Two-way integrated speaker with piezoelectric diaphragm as tweeter

Abstract

The present disclosure relates to a bidirectional integrated loudspeaker with a piezoelectric diaphragm as a tweeter. Aspects of the subject technology relate to a device that includes a moving-coil loudspeaker that includes a diaphragm to play low-frequency signals from an audio signal source, and a piezoelectric transducer coupled to the diaphragm to play high-frequency signals from the audio signal source. A coupler couples the diaphragm to a housing of the device.

Description

TECHNICAL FIELD

[0001] This specification generally relates to audio systems including a bi-directional integrated system including a moving coil micro speaker woofer with a lead-free piezoelectric diaphragm as a tweeter. BACKGROUND

[0002] In a sound system, a woofer is a speaker designed to play low frequency (bass) signals and can not be efficient when playing high frequency (treble) signals. A woofer typically has a lower resonant frequency and operates into voltage headroom, and if used to play high frequency signals, can generate a large amount of heat due to its heavy moving mass and high inductance from the coil. Additionally, if used to play full audio bandwidth, a woofer can reduce audio fidelity. A conventional tweeter is also a moving coil speaker that is designed to be efficient when playing high frequency signals. A tweeter has a higher resonant frequency and is relatively compact. Thus, a combination of a woofer and a tweeter is used to cover the entire audio bandwidth to maintain fidelity.

[0003] Some electronic devices incorporate such bi-directional audio systems, for example, by using four moving coil woofers and four moving coil tweeters as separate modules, with a crossover frequency of about 2.5 kHz or lower. Bi-directional audio systems utilize two different modules (one woofer and one tweeter). This becomes increasingly challenging as electronic devices are severely constrained in terms of space requirements and module cost. BRIEF DESCRIPTION OF DRAWINGS

[0004] Some features of the subject technology are set forth in the appended claims. However, for purpose of explanation, several aspects of the subject technology are set forth in the following figures.

[0005] Figure 1 A cross-sectional view of an example of a bi-directional integrated speaker module according to aspects of the subject technology is shown.

[0006] Figure 2A And Figure 2B Top and cross-sectional views of a bi-directional integrated speaker system module according to aspects of the subject technology are shown. Figure 1

[0007] Figure 3A And Figure 3B Top and cross-sectional views of a bi-directional integrated speaker system module according to aspects of the subject technology are shown.

[0008] Figure 4 ​A cross-sectional view showing an example of a bidirectional integrated speaker module with a secondary coil is shown in accordance with various aspects of the subject technology.

[0009] Figure 5 A flow diagram showing an example process of manufacturing a bidirectional integrated speaker system module is shown in accordance with various aspects of the subject technology.

[0010] Figure 6 A wireless communication device in which some aspects of the subject technology are implemented is shown. DETAILED DESCRIPTION

[0011] The detailed description shown below is intended as a description of various configurations of the subject technology and is not intended to represent the only configurations in which the subject technology can be practiced. The appended drawings are incorporated herein and constitute a part of the detailed description. The detailed description includes specific details for the purpose of providing a thorough understanding of the subject technology. However, it will be clear and apparent to those skilled in the art that the subject technology is not limited to the specific details set forth herein and can be practiced without some of the specific details. In some instances, well-known structures and components are shown in block diagram form, so as to avoid obscuring the concepts of the subject technology.

[0012] The present disclosure relates to a bidirectional integrated system comprising a moving coil micro speaker woofer with a lead-free piezoelectric diaphragm as a tweeter. The subject technology combines a moving coil woofer and a piezoelectric tweeter into a single standalone module, which saves space while maintaining audio performance and fidelity. The moving coil woofer generates low frequency sound waves, and the piezoelectric tweeter generates high frequency sound. The standalone device of the subject technology utilizes piezoelectricity generated by the application of an electric field to create a strain in the piezoelectric material. The piezoelectric tweeter can be very thin (e.g., thickness in the range of about 50-150 pm) and have a high resonance frequency with relatively less displacement compared to traditional moving coil speakers, and thus a good fit for high frequency applications. Furthermore, the piezoelectric tweeter can dissipate almost no heat, as they are a capacitive load and have no traditional voice coil in the magnet assembly. This can be an advantageous feature, as a large number of electronic devices such as smartphones, tablets, and laptops are heat-limited due to the heat generated by traditional coils in the speakers.

[0013] Figure 1A cross-sectional view of an example of a bidirectional integrated speaker module 100 is shown in accordance with various aspects of the subject technology. The bidirectional integrated speaker module 100 (hereinafter speaker module 100) includes a housing 110, a magnet 120, a voice coil 130, a diaphragm 140, and a piezoelectric transducer 150. The voice coil 130 is a conventional moving coil that can generate low frequency (e.g., bass) sound by causing up and down motion of the diaphragm 140. High frequency sound is produced due to the radial motion (e.g., expansion or contraction) of the piezoelectric transducer 150, which is bonded to the diaphragm 140 with a suitable adhesive. In some implementations, the piezoelectric transducer 150 is a thin ceramic (or other material) disk, with a thickness in the range of about 80-120 pm, and is bonded to the diaphragm 140 or formed on the diaphragm 140. In one or more implementations, high frequency audio signals are separated by a high pass filter and provided to the piezoelectric transducer 150 via conductive traces and a suitable bias voltage. In some implementations, the piezoelectric transducer 150 can be driven with a different voltage than the diaphragm 140.

[0014] In some implementations, the diaphragm 140 is made of a metal such as aluminum or similar metal, and is coupled to the housing 110 via a coupler (surround) 160, which can be made of a flexible material. The voice coil 130 is placed in a cylindrical cavity within the magnet 120, which is made of a ferromagnetic material. The voice coil 130 can receive low frequency audio signals from an audio source via a low pass filter. In some implementations, the piezoelectric transducer 150 can be polarized in the thickness direction of the diaphragm 140, which produces radial strain on the top or bottom of the diaphragm 140. The piezoelectric transducer 150 can receive high frequency audio signals from an audio source via a high pass filter via conductive traces that can be formed on the diaphragm 140. As described above, in the speaker module 100, low frequency sound waves and high frequency sound waves can be produced by the up and down motion of the diaphragm 140 and the radial motion of the piezoelectric transducer 150, respectively. The radial motion of the piezoelectric transducer 150 is in a direction perpendicular to the direction of the up and down motion of the diaphragm 140, and can cause flexing and / or bending of the diaphragm itself, thereby producing sound pressure at high frequencies. Bonding the piezoelectric transducer 150 to the diaphragm 140 can also contribute to the stiffness and rigidity of the diaphragm 140. The adhesion of the diaphragm 140 to the coupler 160 can be carefully implemented to further suppress resonant structural modes of the diaphragm 140.

[0015] Figure 2A and Figure 2B A cross-sectional view of an example of a bidirectional integrated speaker module 100 is shown in accordance with various aspects of the subject technology. The bidirectional integrated speaker module 100 (hereinafter speaker module 100) includes a housing 110, a magnet 120, a voice coil 130, a diaphragm 140, and a piezoelectric transducer 150. The voice coil 130 is a conventional moving coil that can generate low frequency (e.g., bass) sound by causing up and down motion of the diaphragm 140. High frequency sound is produced due to the radial motion (e.g., expansion or contraction) of the piezoelectric transducer 150, which is bonded to the diaphragm 140 with a suitable adhesive. In some implementations, the piezoelectric transducer 150 is a thin ceramic (or other material) disk, with a thickness in the range of about 80-120 pm, and is bonded to the diaphragm 140 or formed on the diaphragm 140. In one or more implementations, high frequency audio signals are separated by a high pass filter and provided to the piezoelectric transducer 150 via conductive traces and a suitable bias voltage. In some implementations, the piezoelectric transducer 150 can be driven with a different voltage than the diaphragm 140. Figure 1FIGS. 2A and 2B, respectively, illustrate a top view 200A and a cross-sectional view 200B of a bidirectional integrated loudspeaker system module 100, according to various aspects of the subject technology. The top view 200A illustrates a piezoelectric transducer 150 bonded to a diaphragm 140. In the example implementation depicted in the top view 200A, the piezoelectric transducer 150 has a circular shape, although the shape is not limited to circular and can follow the shape of the diaphragm 140. In some implementations, the area of the piezoelectric transducer 150 is approximately, although not limited to, 70% to 90% of the area of the diaphragm 140. In one or more implementations, the piezoelectric transducer 150 can be a piezoelectric ceramic disc made of a thin film (e.g., in the range of approximately 50-150 pm) of lead zirconate titanate (PZT), for example.

[0016] The cross-sectional view 200B illustrates the diaphragm 140 having a convex shape to facilitate vibration of the diaphragm 140. The piezoelectric transducer 150 conforms to the convex shape of the diaphragm 140 to form a durable bond. In some implementations, the amount of curvature of the diaphragm 140 is not limited to the curvature shown and can be smaller or larger depending on the metal used.

[0017] Figure 3A and Figure 3B FIGS. 3A and 3B, respectively, illustrate a top view 300A and a cross-sectional view 300B of a bidirectional integrated loudspeaker system module, according to various aspects of the subject technology. The top view 300A illustrates a piezoelectric transducer 350 bonded to a diaphragm 140. In the example implementation depicted in the top view 300A, the piezoelectric transducer 350 is a ring having a circular shape, although the shape is not limited to circular and can follow the shape of the diaphragm 140. In some implementations, the area of the piezoelectric transducer 350 is approximately, although not limited to, 10% to 20% of the area of the diaphragm 140, which can make it less efficient than the piezoelectric transducer 150 of Figures 2A-2B However, an advantageous feature of the piezoelectric transducer 350 is that it can reduce interference. In one or more implementations, the piezoelectric transducer 350 can be a piezoelectric ceramic made of a thin film (e.g., 100 pm) of PZT, for example. In some implementations, the high frequency audio signal is separated by a high pass filter and provided to the piezoelectric transducer 350 through a conductive trace along with a suitable bias voltage.

[0018] The cross-sectional view 300B illustrates the diaphragm 140 having a convex shape and the piezoelectric transducer 350 conforms to the convex shape of the diaphragm 140 to form a durable bond. In some implementations, the amount of curvature of the diaphragm 140 is not limited to the curvature shown and can be smaller or larger depending on the metal used to manufacture the diaphragm 140.

[0019] Figure 4A cross-sectional view showing an example of a bidirectional integrated speaker module 400 with a secondary coil is shown in accordance with various aspects of the subject technology. The bidirectional integrated speaker module 400 has one or more of the features of the bidirectional integrated speaker module 100, such as a housing 410, a magnet 420, a primary coil 430, a diaphragm 440, and a piezoelectric transducer 450, which are analogous to the housing 110, the magnet 120, the voice coil 130, the diaphragm 140, and the piezoelectric transducer 150, respectively, as described above with respect to Figure 1

[0020] Additional features of the bidirectional integrated speaker module 400 include a secondary coil 432, a substrate layer 460, and a plating layer 470, which sandwich the piezoelectric transducer 450 and are connected to two terminals 442-1 and 442-2 of the secondary coil 432, respectively. The substrate layer 460 and the plating layer 470 can be made of an electrically conductive material, such as a metal, for example, copper, silver, aluminum, tungsten, or other suitable electrically conductive material.

[0021] The secondary coil 432 can not be connected to any external voltage or current source, and can not have any electrical connection to the primary coil 430. The secondary coil 432 is magnetically excited by magnetic coupling to the magnetic field generated by the primary coil 430. The voltage generated at the terminals 442-1 and 442-2 due to the magnetic coupling is applied to the piezoelectric transducer 450 via the substrate layer 460 and the plating layer 470, respectively. The primary coil 430 provides broadband actuation of the piezoelectric transducer 450 as a piston. The secondary coil 432 directly and at higher voltage excites the piezoelectric transducer 450.

[0022] Figure 5 A flowchart of an example process 500 to manufacture a bidirectional integrated speaker system module is shown in accordance with various aspects of the subject technology. For explanatory purposes, the process 500 is primarily described herein with reference to the speaker module 100 of Figure 1 However, the process 500 is not limited to the speaker module 100 of Figure 1 and one or more blocks (or operations) of the process 500 can be performed by one or more other components of other suitable devices, such as earbuds, headphones, headsets, etc. Further for explanatory purposes, the blocks of the process 500 are described herein as occurring in sequence or linearly. However, multiple blocks of the process 500 can occur in parallel. Moreover, the blocks of the process 500 need not be performed in the order shown and / or one or more blocks of the process 500 need not be performed and / or can be replaced by other operations.

[0023] The process 500 begins with a diaphragm (e.g., 140 of Figure 1 being coupled to a voice coil (e.g., 130 of Figure 1 in response to a connection to a device (e.g., 100 of Figure 1 ​100) of the audio signal source (e.g., Figure 6 The 660) receives a low-frequency audio signal and generates a low-frequency audio wave (510). A piezoelectric transducer (e.g., Figure 1 (520) is coupled to the diaphragm to generate a high-frequency audio wave in response to receiving a high-frequency audio signal from an audio signal source. The diaphragm is coupled to the housing of the device (e.g., Figure 1 110)(530).

[0024] Figure 6 A wireless communication device in which some aspects of the techniques of this subject matter are implemented is illustrated. In one or more embodiments, the wireless communication device 600 may be a tablet computer, smartphone, or smartwatch, which may use a bidirectional integrated speaker system module of the techniques of this subject matter, such as... Figure 1 As depicted herein, the wireless communication device 600 may include a radio frequency (RF) antenna 610, a duplexer 612, a receiver 620, a transmitter 630, a baseband processing module 640, a memory 650, a processor 660, and a local oscillator (LOGEN) 670. In various aspects of the subject matter art, Figure 6 One or more boxes represented therein may be integrated on one or more semiconductor substrates. For example, boxes 620 to 870 may be implemented on a single chip or a single system-on-a-chip, or in a multi-chip chipset.

[0025] Receiver 620 may include suitable logic circuitry and / or code operable to receive and process signals from RF antenna 610. Receiver 620 may, for example, be operable to amplify and / or down-convert received wireless signals. In various aspects of the subject matter, receiver 620 is operable to eliminate noise in the received signal and is linear over a wide frequency range. Thus, receiver 620 is suitable for receiving signals according to various wireless standards such as Wi-Fi, WiMAX, Bluetooth, and various cellular standards. In various aspects of the subject matter, receiver 620 may not use any sawtooth acoustic wave (SAW) filters and uses little or no off-chip discrete components such as large capacitors and inductors.

[0026] The transmitter 630 can include suitable logic, circuitry, and / or code that can be operable to process and transmit signals from the RF antenna 610. The transmitter 630, for example, can be operable to upconvert and amplify RF signals. In various aspects of the subject technology, the transmitter 630 can be operable to upconvert and amplify baseband signals processed in accordance with a variety of wireless standards. Examples of such standards can include Wi-Fi, WiMAX, Bluetooth, and various cellular standards. In various aspects of the subject technology, the transmitter 630 can be operable to provide signals for further amplification by one or more power amplifiers.

[0027] The duplexer 612 can provide isolation in the transmit frequency band to avoid saturation of the receiver 620 or damage to components of the receiver 620 and to relax one or more design requirements of the receiver 620. In addition, the duplexer 612 can attenuate noise in the receive frequency band. The duplexer 612 can be operable in multiple frequency bands of various wireless standards.

[0028] The baseband processing module 640 can include suitable logic, circuitry, and / or code that can be operable to perform baseband signal processing. The baseband processing module 640 may, for example, analyze received signals and generate control and / or feedback signals for configuring various components of the wireless communication device 600, such as the receiver 620. The baseband processing module 640 can be operable to encode, decode, transcode, modulate, demodulate, encrypt, decrypt, scramble, descramble, and / or otherwise process data in accordance with one or more wireless standards.

[0029] The processor 660 can include suitable logic, circuitry, and / or code that can enable processing of data and / or control operation of the wireless communication device 600. In this regard, the processor 660 can enable provision of control signals to various other portions of the wireless communication device 600. The processor 660 can also control transmission of data between various portions of the wireless communication device 600. Additionally, the processor 660 can enable implementation of an operating system or otherwise execute code to manage operation of the wireless communication device 600. In one or more implementations, the processor 660 can be used to perform audio processing and provide audio signals for a bidirectional integrated speaker system module of the subject technology.

[0030] Memory 650 can include suitable logic, circuitry, and / or code that can enable storage of various types of information, such as received data, generated data, code, and / or configuration information. Memory 650 can include, for example, RAM, ROM, flash memory, and / or magnetic storage. In various aspects of the subject technology, information stored in memory 650 can be used to configure receiver 620 and / or baseband processing module 640. In some implementations, memory 650 can store image information of processed and / or unprocessed fingerprint images from an under-display fingerprint sensor of the subject technology.

[0031] LOGEN 670 can include suitable logic, circuitry, interfaces, and / or code that can operate to generate one or more oscillating signals at one or more frequencies. LOGEN 670 can operate to generate digital signals and / or analog signals. As such, LOGEN 670 can operate to generate one or more clock signals and / or sinusoidal signals. Characteristics of the oscillating signals, such as frequency and duty cycle, can be determined based on one or more control signals from, for example, processor 660 and / or baseband processing module 640.

[0032] In operation, processor 660 can configure various components of wireless communication device 600 based on a wireless standard for which the device is designed to receive signals. Wireless signals can be received via RF antenna 610, amplified, and down-converted by receiver 620. Baseband processing module 640 can perform noise estimation and / or noise cancellation, decoding, and / or demodulation of the baseband signals. As such, information in the received signals can be properly recovered and utilized. For example, the information can be audio and / or video to be presented to a user of wireless communication device 600, data to be stored to memory 650, and / or information to affect and / or enable the operation of wireless communication device 600. Baseband processing module 640 can modulate, encode, and perform other processing on audio, video, and / or control signals to be transmitted by transmitter 630 in accordance with a variety of wireless standards.

[0033] The various functions described above can be implemented in digital electronic circuitry, in computer software, firmware or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of them. The technology can be implemented using one or more computer program products. Programmable processors and computers can include, in addition to one or more processors, memory (e.g., volatile memory, non-volatile memory, or both), and storage devices. Generally, a computer includes a system bus for communicating information, and a processor coupled with the system bus for processing information. With such a configuration, the computer can be a mobile device or be packaged as a mobile device. The processes and logic flows can be performed by one or more programmable processors and by one or more programmable logic circuitry. General and special purpose computing devices and storage devices can be interconnected through communication networks.

[0034] Some implementations include electronic components, such as microprocessors, and storage that store computer program instructions in a machine- readable or computer-readable (or processed data) medium (also referred to as computer- readable storage media) such as a

[0035] While the above discussion primarily refers to microprocessor or multi-core processors that execute software, some implementations are performed by one or more integrated circuits such as application specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). In some implementations, such integrated circuits execute instructions that are stored on the circuit itself.

[0036] As used in this description and claims, the terms “computer”, “processor”, and “memory” all refer to electronic or other technological devices. These terms exclude people or groups of people. For purposes of this description, the term “display” or “displaying” mean displaying on an electronic device. As used in this description and claims, the terms “computer readable medium” and “computer readable media” are entirely restricted to tangible, physical objects that store information in a form that is readable by a computer. These terms exclude any wireless signals, wired download signals, and any other ephemeral signals.

[0037] To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube), LCD (liquid crystal display), LED (Light Emitting Diode) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input.

[0038] Many of the above-described features and applications can be implemented as software processes that are specified as a set of instructions recorded on a computer readable storage medium (also referred to as computer readable medium). When these instructions are executed by one or more processing unit(s) (e.g., one or more processors, cores of processors, or other processing units), they cause the processing unit(s) to perform the actions indicated in the instructions. Examples of computer readable media include, but are not limited to, flash drives, RAM chips, hard drives, and EPROMs. The computer readable media does not include carrier waves and electronic signals over wire, fiber optic, or other communication media.

[0039] In this specification, the term "software" is meant to include firmware residing in read-only memory or applications stored in magnetic storage which can be read into memory for processing by a processor. Also, in some embodiments, various software aspects of the subject disclosure can be implemented as sub-parts of a larger program, where the sub-parts can be stored in any number of locations, including on the read-only memory, in the magnetic storage, in the memory, or elsewhere. In some embodiments, the software aspects can be implemented as a single program, or as any number of separate programs. Finally, any combination of separate programs that together implement a software aspect described here is within the scope of the subject disclosure. In some embodiments, the software programs, when installed to operate on one or more electronic systems, define one or more specific machine implementations that execute and perform the operations of the software programs.

[0040] A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more modules, sub programs, or code portions). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and

[0041] It should be understood that the particular order in which the steps of processes presented in this disclosure can be performed can depend as desired by the design. The particular order of steps set forth in processes should not be construed as causing the described processes to be limited to only those steps outlined. Other steps that are not mentioned can be incorporated in the steps of processes. Some of the steps can be performed simultaneously. For example, in certain situations, multitasking and parallel processing can be advantageous. Moreover, the dividing of system components in the aspects described above should not be understood as requiring such division in all aspects, and it should be understood that the program components and systems can generally be integrated together in a single software product or packaged into multiple software products.

[0042] The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more." Unless otherwise noted, the term "some" refers to one or more. The term "coupled" as used herein is intended to mean coupled either directly or indirectly through one or more intervening components. The term "program" refers to one or more computer programs, software components, or other software elements. The term "processor" refers to one or more processors or processing units. The term "memory" refers to one or more memories, one or more random access memories (RAM), or one or more read only memories (ROM). The term "inference" as used herein is intended to refer to an action taken as a result of statistical analysis, probabilistic analysis, or employing a probabilistic model, such as a neural network, a support vector machine, a decision tree, a Bayesian network, or any other appropriate probabilistic analysis or model.

[0043] The verb phrase "configured to," "operable to," and "programmed to" do not necessarily express the manner in which a subject is "configured," "operable," or "programmed." For example, a processor configured to monitor and control operations is not necessarily

[0044] The phrase "aspect" does not mean that this aspect is required by the subject technology or that this aspect applies to all configurations of the subject technology. A disclosure related to one aspect can apply to all configurations or one or more configurations. The phrase "aspect" can refer to one or more aspects, and vice versa. The phrase "configuration" does not mean that this configuration is required by the subject technology or that this configuration applies to all configurations of the subject technology. A disclosure related to a configuration can apply to all configurations or one or more configurations. The phrase "configuration" can refer to one or more configurations, and vice versa.

[0045] The word "example" is used herein to mean "serving as an example or illustration." Any aspect or design described herein as "example" is not necessarily to be construed as preferred or advantageous over other aspects or designs.

[0046] As described above, one aspect of the communication devices within which the present technology can be implemented is the collection and use of data available from a variety of sources to detect and track performance of physical activity events. The present disclosure contemplates that, in some instances, such collected data can include personal information data that uniquely identifies or can be used to contact or locate a specific person. Such personal information data can include demographic data, location-based data, telephone numbers, email addresses, twitter accounts, home addresses, data or records pertaining to a user’s health or health status, birth date, or any other identifying or personal information.

[0047] It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled in a manner that minimizes the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

[0048] All structural and functional equivalents to the elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether these disclosure is explicitly recited in the claims. No claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for.” Furthermore, to the extent that the term “comprising” is used in the detailed description and claims, it is intended to be equivalent to the term “including” within the meaning of 35 U.S.C. § 112(f). Additionally, none of the claims are intended to invoke 35 U.S.C. § 112(f) unless the exact words “means for” are followed by a participle.

Claims

1. An electronic device comprising: a moving coil micro speaker comprising: a diaphragm configured to produce low frequency signals from an audio signal source; a piezoelectric transducer coupled to the diaphragm and configured to produce high frequency signals from the audio signal source; a coupler configured to couple the diaphragm to a housing of the electronic device; a voice coil configured to receive the low frequency signals from the audio signal source; and a secondary coil magnetically coupled to the voice coil and configured to excite the piezoelectric transducer.

2. The electronic device of claim 1, wherein the diaphragm comprises a metallic diaphragm, and wherein the metallic diaphragm is made of aluminum.

3. The electronic device of claim 1, wherein the piezoelectric transducer comprises a piezoelectric disc made of a lead zirconate titanate (PZT) thin film, and wherein the piezoelectric disc is bonded to the diaphragm.

4. The electronic device of claim 3, wherein a thickness of the piezoelectric disc is in a range of about 50-150 pm, and wherein the piezoelectric disc is formed on the diaphragm.

5. The electronic device of claim 1, wherein an area of the piezoelectric transducer is less than an area of the diaphragm.

6. The electronic device of claim 1, wherein the piezoelectric transducer comprises a piezoelectric ring made of a lead zirconate titanate (PZT) thin film, and wherein the piezoelectric ring is bonded to the diaphragm.

7. The electronic device of claim 6, wherein a thickness of the piezoelectric ring is in a range of about 50-150 pm, and wherein the piezoelectric ring is formed on the diaphragm.

8. The electronic device of claim 1, wherein the piezoelectric transducer receives the high frequency signals from the audio signal source via a conductive trace.

9. The electronic device of claim 1, wherein the voice coil is configured to move within a cavity of a magnet.

10. The electronic device of claim 9, wherein the magnet and the voice coil are assembled within the housing, wherein terminals of the secondary coil are coupled to a substrate and a plating layer, and wherein the piezoelectric transducer is sandwiched between the substrate and the plating layer.

11. A method for manufacturing a speaker module comprising: coupling a diaphragm to a voice coil to produce low frequency audio waves in response to receiving low frequency audio signals from an audio signal source connected to a device; coupling a piezoelectric transducer to the diaphragm to produce high frequency audio waves in response to receiving high frequency audio signals from the audio signal source; coupling the diaphragm to a housing of the device; and assembling the voice coil, along with a secondary coil and a magnet, within the housing of the device, wherein the secondary coil is magnetically coupled to the voice coil and configured to excite the piezoelectric transducer.

12. The method of claim 11, wherein coupling the piezoelectric transducer to the diaphragm comprises coupling a piezoelectric disc made of a lead zirconate titanate (PZT) thin film to the diaphragm made of a metal, wherein the metal comprises aluminum. ​ 13. The method of claim 11, wherein coupling the piezoelectric transducer to the diaphragm comprises bonding the piezoelectric transducer to the diaphragm.

14. The method of claim 11, wherein coupling the piezoelectric transducer to the diaphragm comprises coupling a piezoelectric ring made of a lead zirconate titanate (PZT) thin film to the diaphragm made of a metal, wherein the metal comprises aluminum.

15. The method of claim 11, further comprising configuring the voice coil to move within a cavity of a magnet.

16. The method of claim 11, further comprising: stacking the piezoelectric transducer between a plating layer and a substrate, and coupling terminals of the secondary coil to the plating layer and the substrate.

17. The method of claim 11, further comprising configuring the piezoelectric transducer to receive high frequency audio signals from the audio signal source via conductive traces formed on the diaphragm.

18. A speaker comprising: a primary coil configured to receive low frequency signals of an audio signal from an audio signal source; a diaphragm configured to play the low frequency signals of the audio signal; a piezoelectric transducer coupled to the diaphragm and configured to play high frequency signals of the audio signal; and a secondary coil magnetically coupled to the primary coil and configured to excite the piezoelectric transducer, wherein the diaphragm is coupled to a housing of the speaker, wherein the housing is configured to integrate the diaphragm and the piezoelectric transducer.

19. The speaker of claim 18, wherein the piezoelectric transducer comprises one of a piezoelectric disc or a piezoelectric ring made of a lead zirconate titanate (PZT) thin film.

20. The speaker of claim 18, wherein the piezoelectric transducer is sandwiched between a plating layer and a substrate.

21. The speaker of claim 20, wherein terminals of the secondary coil are coupled to the plating layer and the substrate. ​

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