Audio output device

Abstract

The acoustic output device according to the embodiments of this specification includes a bone conduction voice generation unit that generates bone conduction sound waves transmitted to a person's ear through bone and having at least one resonance peak within a frequency range of 1 kHz or less, and a piezoelectric voice generation unit that generates sound waves having at least one resonance peak within a frequency range of 6 kHz or more.

Description

Technical Field

[0001] This specification relates to the field of acoustics, particularly to acoustic output devices.

Background Art

[0002] Voice output includes low-frequency output, intermediate-frequency output, and high-frequency output. The high-frequency output of conventional acoustic output devices is generally insufficient, which affects their sound quality performance. In particular, in the field of bone conduction acoustics, the transmission attenuation of high-frequency voice through bone conduction is large, and improvement of high-frequency output is strongly desired.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Therefore, it is desirable to provide an acoustic output device capable of improving high-frequency output.

Means for Solving the Problems

[0004] An acoustic output device according to an embodiment of this specification includes a bone conduction voice generation unit that generates bone conduction sound waves transmitted to a person's ear through bone and having at least one resonance peak within a frequency range of 1 kHz or less, and a piezoelectric voice generation unit that generates sound waves having at least one resonance peak within a range of 6 kHz or more.

Brief Description of the Drawings

[0005] [Figure 1] It is a block diagram of an acoustic output device according to some embodiments of this specification. [Figure 2] It is a frequency response curve diagram of a bone conduction voice generation unit, a piezoelectric voice generation unit, and their combination according to some embodiments of this specification. [Figure 3A] It is a schematic configuration diagram of an acoustic output device according to some embodiments of this specification. [Figure 3B] It is a schematic configuration diagram of an acoustic output device according to some other embodiments of this specification. [Figure 4] This is an illustrative structural diagram of a piezoelectric sound generation unit according to some embodiments of this specification. [Figure 5] This is an illustrative structural diagram of a piezoelectric sound generation unit according to some embodiments of this specification. [Figure 6A] This is an illustrative structural diagram of an acoustic output device according to some embodiments of this specification. [Figure 6B] This is an illustrative structural diagram of an acoustic output device according to some further embodiments of this specification. [Figure 7A] This is a schematic diagram of an acoustic output device according to some embodiments of this specification. [Figure 7B] This is a schematic diagram of an acoustic output device according to some embodiments of this specification. [Figure 8A] This is a schematic diagram of another acoustic output device according to some embodiments of this specification. [Figure 8B] This is a schematic diagram of a bone conduction sound generation unit according to some embodiments of this specification. [Figure 9] This is a schematic diagram of a further acoustic output device according to some embodiments of this specification. [Modes for carrying out the invention]

[0006] To more clearly illustrate the technical means of the embodiments of this application, the drawings necessary for describing the embodiments are briefly described below. Clearly, the drawings described below are only a part of the examples or embodiments of this application, and those skilled in the art can apply this application to other similar scenarios based on these drawings without requiring any creative effort. Unless otherwise stated or otherwise evident from the context, the same reference numerals in the figures represent the same structure or operation.

[0007] It should be understood that the terms “system,” “apparatus,” “unit,” and / or “module” as used herein are ways of distinguishing various assemblies, elements, components, parts, or assemblies of different levels. However, other terms may be used in place of the above terms if they can achieve the same purpose.

[0008] As shown in the present application and claims, unless the context explicitly indicates otherwise, terms such as “one,” “one,” “one kind,” and / or “the” do not specifically mean singular and may include plural forms. Generally, the terms “includes” and “contains” merely indicate the inclusion of clearly identified steps and elements, and these steps and elements are not an exclusive list; the method or apparatus may also include other steps or elements.

[0009] The embodiments described herein describe an acoustic output device. In some embodiments, the acoustic output device may include a bone conduction sound generation unit and a piezoelectric sound generation unit. The bone conduction sound generation unit can generate bone conduction sound waves having at least one resonance peak in a frequency range of 1 kHz or less, and the piezoelectric sound generation unit can generate sound waves having at least one resonance peak in a frequency range of 6 kHz or more. Specifically, the bone conduction sound generation unit outputs intermediate frequency sound waves, and the piezoelectric sound generation unit outputs high frequency sound waves by utilizing its own characteristics (e.g., the natural frequency of the piezoelectric element included in the piezoelectric sound generation unit). By the complementary cooperation of the two, the acoustic output device can achieve a good sound output effect at high frequencies, and the user can receive a large listening volume in the high-frequency band when wearing the acoustic output device. In some embodiments, the piezoelectric sound generation unit and the bone conduction sound generation unit may be arranged on the side of the acoustic output device housing that contacts the person's face, and generate bone conduction sound waves that are transmitted to the person's ears via the bone. In some embodiments, the bone conduction sound generation unit may be positioned on the side of the acoustic output device housing that contacts the person's face and generates bone conduction sound waves transmitted to the person's ears via bone, while the piezoelectric sound generation unit may be positioned in a location on the acoustic output device housing that does not contact the person's face and the mechanical vibrations generated by the piezoelectric sound generation unit are transmitted to the housing, which then generates bone conduction sound waves transmitted to the person's ears via bone, or the housing generates air conduction sound waves transmitted to the person's ears via air, or the mechanical vibrations of the piezoelectric sound generation unit drive and vibrate the surrounding air, generating air conduction sound waves transmitted to the person's ears via air. The acoustic output device according to the embodiments herein expands the frequency response range of the acoustic output device by complementing the high-frequency sound output using the piezoelectric sound generation unit, thereby realizing a rich auditory experience in which sound is heard more clearly and in greater detail.

[0010] Figure 1 is a block diagram of an acoustic output device according to some embodiments of this specification. As shown in Figure 1, the acoustic output device 100 may include a bone conduction sound generation unit and a piezoelectric sound generation unit.

[0011] The acoustic output device 100 is used to convert an audio signal (e.g., an electrical signal containing speech information) into a speech signal. In some embodiments, the speech signal may include bone conduction and / or air conduction. For example, the acoustic output device 100 can generate mechanical vibrations in response to a received audio signal to output sound waves (i.e., a speech signal), which may be transmitted to a person's ear by bone conduction or air conduction. The above conversion process may involve the coexistence and conversion of several different types of energy, for example, an optical signal (i.e., a signal containing speech information) may be converted into a speech signal. Other types of energy that can coexist and be converted during the operation of the acoustic output device 100 include thermal energy, magnetic field energy, and the like. In some embodiments, the type of acoustic output device 100 may include one or more types from among moving coil type, electrostatic type, piezoelectric type, balanced armature type, pneumatic type, electromagnetic type, etc.

[0012] The bone conduction sound generation unit 110 is used to convert an audio signal into bone conduction sound waves. In some embodiments, the bone conduction sound generation unit 110 may include a vibrating element (also called a transducer device) and a vibration transmission element, at least a part of the structure of the vibration transmission element (for example, one side of the vibration transmission element body or a silicone layer covering the vibration transmission element body) may be in direct contact with the user's face, the vibrating element generates mechanical vibrations in response to the audio signal, the vibration transmission element vibrates in response to the vibration of the vibrating element and transmits the vibrations it receives (i.e., bone conduction sound waves) directly to the user's ears via the user's muscles, bones, blood, etc. In some embodiments, the acoustic output device 100 may include a housing, and the vibrating element may be connected to the housing via an elastic element (e.g., a vibration transmission sheet) or directly to the housing, and when the user wears the acoustic output device 100, at least a part of the structure of the housing (e.g., the side wall of the housing or the silicone layer covering the side wall) may come into contact with the user's face, and the housing may transmit the vibrations it receives (i.e., bone conduction sound waves) to the user's ears via the user's muscles, bones, blood, etc. The bone conduction sound generation unit 110 outputs bone conduction sound waves and, at the same time, its vibrations drive the surrounding air to vibrate, generating a small amount of air conduction sound waves. For more details regarding the bone conduction sound generation unit 110, please refer to other parts of this specification, for example, Figures 3A, 3B, 6A to 9 and their related descriptions.

[0013] The piezoelectric sound generation unit 120 is used to convert an audio signal into bone-conducted and / or air-conducted sound waves. In some embodiments, the piezoelectric sound generation unit 120 may include one or more piezoelectric elements, each piezoelectric element may be configured to vibrate based on the audio signal. In some embodiments, the audio signal acts on the piezoelectric layer of the piezoelectric element, causing the piezoelectric layer to deform, i.e., generate vibration. When the piezoelectric sound generation unit 120 is used to convert an audio signal into bone-conducted sound waves, the piezoelectric sound generation unit 120 is in direct or indirect contact (for example, via the housing, vibration transmission element, or silicone layer covering the side wall of the housing, vibration transmission element, or piezoelectric sound generation unit 120) with the user's face area to transmit vibrations to the user's ears via the user's muscles, bones, blood, etc., thereby achieving bone-conducted sound wave output. In some embodiments, the piezoelectric sound generation unit 120 may include a piezoelectric element and a vibration transmission sheet, the piezoelectric element may be connected to a housing via the vibration transmission sheet, and in response to the action of a drive voltage, the piezoelectric element vibrates to drive the vibration transmission sheet to generate mechanical vibration, the vibration transmission sheet transmits the mechanical vibration to the housing and, through the housing, transmits the mechanical vibration to the user's face area to generate bone conduction sound waves. In some embodiments, the piezoelectric sound generation unit 120 may be used to convert an audio signal into air conduction sound waves. For example, the piezoelectric sound generation unit 120 vibrates based on an audio signal and transmits the vibration to a housing, the vibration of the housing drives the surrounding air to vibrate and generate air conduction sound waves, or the piezoelectric sound generation unit 120 vibrates to drive the air around the piezoelectric sound generation unit to vibrate and generate air conduction sound waves. In some embodiments, the piezoelectric sound generation unit 120 may include a piezoelectric element and a vibrating membrane, the piezoelectric element being connected to the vibrating membrane, the piezoelectric element vibrating in response to an audio signal and driving the vibrating membrane to vibrate, the vibrating membrane driving the surrounding air to vibrate, and thereby generating air-conducted sound waves.In some embodiments, the piezoelectric sound generation unit 120 may include a piezoelectric element and a vibration transmission sheet, the piezoelectric element may be connected to the housing via the vibration transmission sheet, and under the action of a driving voltage, the piezoelectric element vibrates, driving the vibration transmission sheet to generate mechanical vibration, the vibration transmission sheet generates mechanical vibration and at the same time drives the surrounding air to vibrate, thereby generating air-conducted sound waves. Furthermore, the vibration transmission sheet transmits the mechanical vibration to the housing, the housing generates mechanical vibration and drives the air near the housing to vibrate, thereby generating air-conducted sound waves. In some embodiments, the housing may include one or more sound ducts, and the air-conducted sound waves in the housing are radiated to the outside through the sound ducts and can be received by a person's ear. In addition, the piezoelectric sound generation unit 120 outputs bone-conducted sound waves and at the same time drives the surrounding air to vibrate, generating a small amount of air-conducted sound waves, and at the same time outputs air-conducted sound waves and at the same time drives the part of the sound output device 100 that comes into contact with a person's face to vibrate, generating a small amount of bone-conducted sound waves. For further details regarding the piezoelectric sound generation unit 120, please refer to other sections of this specification, for example, Figures 3A to 6B and their related descriptions.

[0014] The mechanical vibrations, i.e., bone conduction sound waves, output by the bone conduction sound generation unit 110 described above have at least one resonance peak in a frequency range of 1 kHz or less, meaning that the bone conduction sound generation unit 110 has a good acoustic output effect near the resonance frequency corresponding to that resonance peak. In some embodiments, the bone conduction sound generation unit 110 generates bone conduction sound waves having at least one resonance peak in a frequency range of 100 Hz to 1 kHz. Preferably, the bone conduction sound generation unit 110 generates bone conduction sound waves having at least one resonance peak in a frequency range of 200 Hz to 900 Hz. More preferably, the bone conduction sound generation unit 110 generates bone conduction sound waves having at least one resonance peak in a frequency range of 300 Hz to 800 Hz. The piezoelectric sound generation unit 120 has good sensitivity even at high frequencies (e.g., 1000Hz to 40000Hz) due to the characteristics of the piezoelectric element itself (e.g., the natural frequency of the piezoelectric element), and the sound waves it outputs (bone-conducted sound waves or air-conducted sound waves) have at least one resonance peak within a frequency range of 6kHz or higher (e.g., within a frequency range of 6kHz to 40kHz). In other words, the piezoelectric sound generation unit 120 has a good acoustic output effect near the resonance frequency corresponding to its resonance peak. In some embodiments, the piezoelectric sound generation unit 120 can output sound waves having at least one resonance peak within a frequency range greater than 7kHz. In some embodiments, the piezoelectric sound generation unit 120 can output sound waves having at least one resonance peak within a frequency range greater than 8kHz. In some embodiments, the piezoelectric sound generation unit 120 can output sound waves having at least one resonance peak within a frequency range greater than 9kHz. Specifically, in some embodiments, the piezoelectric sound generation unit 120 can output a sound wave having a single resonant peak at around 10 kHz.Since the acoustic output device 100 simultaneously has a bone conduction sound generation unit 110 and a piezoelectric sound generation unit 120, the sound frequency output of the acoustic output device 100 can cover from intermediate frequencies to high frequencies, achieving the objective of expanding the frequency response range of the acoustic output device 100 and, accordingly, complementing the sound output at high frequencies to realize a rich auditory experience in which sounds are heard more clearly and in more detail.

[0015] Here, with reference to Figure 2, the effect of the piezoelectric sound generation unit 120 in complementing sound output at high frequencies will be explained. Figure 2 is a frequency response curve diagram of a bone conduction sound generation unit, a piezoelectric sound generation unit, and a combination thereof according to some embodiments of this specification. In Figure 2, the horizontal axis represents frequency (Hz), and the vertical axis represents the sound pressure level (dB) of the sound output device at different frequencies. Frequency curve 21 is the frequency response curve when the sound output device has only a bone conduction sound generation unit, frequency curve 22 is the frequency response curve when the sound output device has only a piezoelectric sound generation unit, and frequency curve 23 is the frequency response curve when the sound output device has both a bone conduction sound generation unit and a piezoelectric sound generation unit. As shown in Figure 2, frequency curve 21 has a resonance peak 211 in the frequency range of 100Hz to 1kHz, and the sound pressure level drops significantly at frequencies above 10kHz. Frequency curve 22 has a low sound pressure level in the frequency range of 100Hz to 1kHz, but in the frequency range of 6kHz to 10kHz, the sound pressure level increases significantly as the resonance frequency of the piezoelectric element itself increases, and reaches a peak value around 10kHz. Frequency curve 23 for the combination of bone conduction sound generation unit 110 and piezoelectric sound generation unit 120 has a resonance peak 231 in the frequency range of 100Hz to 1kHz, and a resonance peak 232 in the frequency range of 6kHz to 10kHz, and at frequencies above 10kHz, the sound pressure level of the acoustic output device having bone conduction sound generation unit 110 and piezoelectric sound generation unit 120 is significantly higher than the sound pressure level of the acoustic output device having bone conduction sound generation unit 110 alone. Therefore, as can be seen from Figure 2, by combining it with the piezoelectric sound generation unit 120, the high-frequency output of the bone conduction sound generation unit 110 is complemented, the output sound is heard more clearly, and the frequency response curve between resonance peak 231 and resonance peak 232 is flat, thus guaranteeing good sound quality when the bone conduction sound generation unit 110 and the piezoelectric sound generation unit 120 are combined.

[0016] In some embodiments, the acoustic output device 100 may include at least one excitation source, which may be used to provide an excitation voltage to a piezoelectric element and a bone conduction sound generation unit 110, causing the piezoelectric element and the bone conduction sound generation unit 110 to vibrate under the action of the excitation voltage. To some extent, the excitation voltage provided by the excitation source may be understood as an audio signal, and in some embodiments, the excitation voltage provided by the excitation source may be an audio signal that has undergone a voltage transformation (e.g., boost or buck). In some embodiments, one excitation source may provide the same excitation voltage to the piezoelectric element and the bone conduction sound generation unit 110, or two excitation sources may each provide the same excitation voltage to the piezoelectric element and the bone conduction sound generation unit 110, causing the piezoelectric element and the bone conduction sound generation unit 110 to vibrate under the driving of the same excitation voltage. In some embodiments, the excitation source may provide a low excitation voltage to the piezoelectric element and the bone conduction sound generation unit 110. When driven by a low excitation voltage, the bone conduction sound generation unit 110 mainly generates sound waves of low frequency (e.g., 20Hz to 500Hz), mid-high frequency (e.g., 500Hz to 6kHz), and high frequency (e.g., 6kHz to 20kHz). Because the piezoelectric element itself has a high resonant frequency, it mainly generates high-frequency sound waves, and accordingly, the low-frequency and mid-high frequency sound wave components are less, which helps the piezoelectric sound generation unit 120 and the bone conduction sound generation unit 110 to work together. As a result, the acoustic output device 100 can achieve high-frequency, mid-high frequency, and low-frequency sound waves output by the bone conduction sound generation unit 110 and high-frequency sound waves output by the piezoelectric sound generation unit 120 without installing a frequency division circuit, and the acoustic output device 100 has a good acoustic output effect in each frequency band.Also, when the acoustic output device 100 operates, the bone conduction voice generation unit 110 mainly outputs sound waves of low frequency, medium-high frequency, and high frequency, and the piezoelectric voice generation unit 120 mainly outputs sound waves of high frequency. The sound pressure level of the high-frequency sound waves output by the bone conduction voice generation unit 110 at a frequency higher than a specific frequency (for example, 10 kHz) decreases, and the high-frequency sound waves output by the piezoelectric voice generation unit 120 can compensate for the deficiency in the high-frequency output of the bone conduction voice generation unit 110, thereby improving the acoustic output effect of the acoustic output device 100 at high frequencies.

[0017] The resonance frequency of the piezoelectric element is related to its mass and rigidity. In some embodiments, the resonance frequency of the piezoelectric element can be adjusted by adjusting parameters related to the mass and rigidity of the piezoelectric element (such as length, width, thickness, or material, etc.). For example, by increasing the mass of the piezoelectric element, the resonance frequency of the piezoelectric element can be lowered. In some embodiments, the number of piezoelectric elements may be one or more. In some embodiments, the plurality of piezoelectric elements may be the same piezoelectric element, that is, having the same resonance frequency. The high-frequency bone conduction sound waves output from the plurality of same piezoelectric elements can be superimposed to improve the voice compensation effect in a specific frequency band (for example, high frequency) of the acoustic output device. In some embodiments, the plurality of piezoelectric elements may be different piezoelectric elements, that is, the plurality of piezoelectric elements have different resonance frequencies, and different piezoelectric elements can compensate for the sound pressure level of the bone conduction voice generation unit 110 in different frequency bands. For example, the piezoelectric voice generation unit 120 includes a first piezoelectric element with a resonance frequency of 8 kHz and a second piezoelectric element with a resonance frequency of 12 kHz. The first piezoelectric element can compensate for the sound pressure level of the bone conduction voice generation unit 110 in the frequency range of 5 kHz to 10 kHz, and the second piezoelectric element can compensate for the sound pressure level of the bone conduction voice generation unit 110 within the frequency range of 10 kHz to 14 kHz.

[0018] In some embodiments, the acoustic output device 100 may further include a first boost circuit for boosting the excitation voltage that drives the piezoelectric element generated by the excitation source, where a higher excitation voltage allows the piezoelectric element to generate higher frequency sound waves, avoiding the situation where the piezoelectric element cannot generate sufficiently high frequency sound waves due to its own low resonant frequency. In some embodiments, the piezoelectric sound generation unit 120 can output sound waves having at least one resonant peak in a frequency range of 7 kHz or higher when driven by a higher excitation voltage. As a simple example, if the resonant frequency of the piezoelectric sound generation unit 120 is 8kHz, the piezoelectric sound generation unit 120 needs to compensate for the output of the bone conduction sound generation unit 110 in the frequency range of 10kHz to 14kHz. In this case, the excitation voltage of the piezoelectric sound generation unit 120 can be increased using a boost circuit, and the piezoelectric sound generation unit 120 can output sound with a high sound pressure level in the range of 10kHz to 14kHz by driving the boosted excitation voltage, thereby achieving the objective of compensating for the output of the bone conduction sound generation unit 110 in the frequency range of 10kHz to 14kHz.

[0019] In some embodiments, the acoustic output device 100 may further include a frequency division circuit for performing frequency division based on a first crossover frequency to generate a signal in a first frequency range and a signal in a second frequency range. The first crossover frequency is set within a high frequency range (for example, 5 kHz to 40 kHz). For example, the first crossover frequency may be 5 kHz. A signal lower than the first crossover frequency is a signal in the first frequency range, and a signal higher than the first crossover frequency is a signal in the second frequency range. The signal in the first frequency range is used to drive the bone conduction voice generating unit 110 to generate sound waves in an intermediate frequency range, and the signal in the second frequency range is used to drive the piezoelectric voice generating unit 120 to generate sound waves in a high frequency range. By using the frequency division circuit to generate signals in different frequency ranges and driving the bone conduction voice generating unit 110 and the piezoelectric voice generating unit 120 respectively, the bone conduction voice generating unit 110 intensively generates sound waves in the intermediate frequency range, and the piezoelectric voice generating unit 120 intensively generates sound waves in the high frequency range. At the same time, the piezoelectric voice generating unit 120 can generate sound waves with a sufficiently high frequency to compensate for the high frequency output of the acoustic output device 100. In some embodiments, in order to enable the piezoelectric voice generating unit 120 having a low resonance frequency to generate sound waves with a sufficiently high frequency, the acoustic output device 100 may further include a second booster circuit. The function of the second booster circuit is similar to that of the first booster circuit and is used to boost the signal in the second frequency range. Compared with the signal in the second frequency range at a low voltage, the signal in the second frequency range after boosting enables the piezoelectric voice generating unit 120 to generate sound waves with a higher high frequency.

[0020] In some embodiments, the acoustic output device 100 may further include an air-conducted sound generation unit 130. The air-conducted sound generation unit 130 is used to convert an audio signal into an air-conducted sound wave, which has at least one resonant peak in a frequency range of 500 Hz or less (for example, in a frequency range of 20 Hz to 500 Hz), that is, the air-conducted sound generation unit 130 has a strong acoustic output effect near the resonant frequency corresponding to that resonant peak, i.e., the volume of the sound it outputs is high. In some embodiments, the acoustic output device 100 may simultaneously have an air conduction sound generation unit 130, a bone conduction sound generation unit 110, and a piezoelectric sound generation unit 120. The air conduction sound generation unit 130 is mainly used for low-frequency output, the bone conduction sound generation unit 110 is mainly used for intermediate-frequency output, and the piezoelectric sound generation unit 120 is mainly used for high-frequency output. As a result, the sound output by the acoustic output device 100 can cover a range from low to high frequencies, and the output intensity of the sound is improved across the entire frequency range, effectively improving the overall sound quality.

[0021] In some embodiments, a frequency division circuit included in the acoustic output device 100 can perform frequency division on a signal in a first frequency range based on a second crossover frequency to generate a signal in a first sub-frequency range and a signal in a second sub-frequency range, the second crossover frequency being set within the range of intermediate frequencies (e.g., 500 Hz to 1 kHz), and the second crossover frequency may be 500 Hz, the signal lower than the second crossover frequency being the signal in the first sub-frequency range, and the signal higher than the second crossover frequency being the signal in the second sub-frequency range, the signal in the first sub-frequency range being used to drive the air conduction sound generation unit 130 to generate low-frequency sound waves, and the signal in the second sub-frequency range being used to drive the bone conduction sound generation unit 110 to generate intermediate-frequency sound waves. Further description of the air conduction sound generation unit 130 can be found elsewhere in this specification, for example, in Figures 6A to 6B and their related descriptions.

[0022] The following describes various embodiments in which the acoustic output device 100 includes a bone conduction sound generation unit and a piezoelectric sound generation unit, with reference to Figures 3A to 5.

[0023] Figure 3A is a schematic diagram of an acoustic output device according to some embodiments of this specification. As shown in Figure 3A, the acoustic output device 300A may include a housing 340A, a bone conduction sound generation unit 310A, and a piezoelectric sound generation unit 320A. The housing 340A is a three-dimensional structure having an internal housing space (also called a housing cavity), and when a user puts on the acoustic output device 300A, the side wall 341A of the housing 340A can come into direct contact with the person's face. In some embodiments, the side wall 341A may be one of the side walls of the housing 340A. In some embodiments, the side wall 341A may be installed independently of the housing 340A, and the side wall 341A is connected to the housing 340A via an elastic element (e.g., a vibration damping sheet). In some embodiments, the bone conduction sound generation unit 310A may be installed within the housing space of the housing 340A and may be connected to the side wall 341A or another side wall of the housing 340A via an elastic element (e.g., a vibration transmission sheet and / or a vibration damping sheet), or directly connected. The piezoelectric sound generation unit 320A may be directly connected to the side wall 341A. The vibrations generated by the installation of the bone conduction sound generation unit 310A and the piezoelectric sound generation unit 320A may be transmitted directly to the user's muscles, bones, blood, etc., or via the side wall 341A. In some embodiments, the piezoelectric sound generation unit 320A may consist only of a piezoelectric element, which may be installed on the inner or outer surface of the side wall 341A, or embedded in the side wall 341A. The piezoelectric element may have a plate-like structure, and at least a portion of the edge of the piezoelectric element is connected to the side wall 341A. For example, in some embodiments, the piezoelectric element may be a circular plate-like structure with its periphery fixed to the side wall 341A, and when a signal is transmitted to the piezoelectric element, the region of the piezoelectric element not fixed to the side wall 341A deforms and vibrates, which is transmitted to the user. Alternatively, in some embodiments, the piezoelectric element may be an annular plate-like structure with its outer or inner periphery fixed to the side wall 341A, and when a signal is transmitted to the piezoelectric element, the region of the piezoelectric element not fixed to the side wall 341A deforms and vibrates, which is transmitted to the user.In some other embodiments, the piezoelectric sound generation unit 320A may include a piezoelectric element and a diaphragm (not shown), the piezoelectric element and the diaphragm located inside the housing 340A, and the piezoelectric element is fixed within the housing space of the housing 340A by a support structure (e.g., a bracket). The piezoelectric element is connected to the side wall 341A via the diaphragm, one side of the diaphragm is connected to the side wall 341A and the other side of the diaphragm is connected to the piezoelectric element, and in response to the action of a driving voltage, the piezoelectric element vibrates, driving the diaphragm to generate mechanical vibration, the diaphragm transmits the mechanical vibration to the housing 340A, and the side wall 341A of the housing 340A transmits the mechanical vibration to the user's face area to generate bone conduction sound waves. The diaphragm may be a structure independent of the housing 340A or the side wall in the housing 340A, or it may be a structure formed integrally with the housing 340A or the side wall in the housing 340A.

[0024] In some embodiments, the housing 340A may be a rectangular parallelepiped structure. In some embodiments, the housing 340A may be a regular or irregular structure such as a cylindrical structure, an ellipsoidal structure, or a trapezoidal structure. In some embodiments, the internal housing space of the housing 340A and its outer contour may have the same or different shapes. For example, the outer contour of the housing 340A may be a rectangular parallelepiped and the housing space may be a rectangular parallelepiped, or for example, the outer contour of the housing 340A may be a rectangular parallelepiped and the housing space may be a sphere.

[0025] As an example, if the housing 340A has a rectangular parallelepiped structure, the side wall 341A of the housing 340A can come into direct contact with a person's face against the outer surface of the housing space. The bone conduction sound generation unit 310A may be connected to the side wall 341A via a vibration transmission element, which vibrates in response to vibrations from the bone conduction sound generation unit 310A and transmits the vibrations it receives to the side wall 341A, and the side wall 341A further transmits the vibrations to the user's face area.

[0026] In some embodiments, the piezoelectric sound generation unit 320A may be installed on the inner surface of the side wall 341A. At least some of the structure of the piezoelectric sound generation unit 320A may be connected to the side wall 341A. For example, the piezoelectric element of the piezoelectric sound generation unit 320A may be a sheet-like structure, a groove may be formed on the inner surface of the side wall 341A, the piezoelectric element may be located in the groove, the edge of the piezoelectric element may be connected to the corresponding side wall of the groove, the piezoelectric element may be substantially parallel to the bottom wall of the groove, and the piezoelectric element and the bottom wall of the groove may be spaced apart, thereby ensuring that the piezoelectric element vibrates in response to the driving voltage. Alternatively, for example, the piezoelectric sound generation unit 320A may include a diaphragm and a piezoelectric element, the piezoelectric element being connected to the inner surface of the side wall 341A via the diaphragm. The diaphragm vibrates in response to the vibration of the piezoelectric element and transmits the vibration it receives to the side wall 341A, which then transmits the vibration to the user's face area. In some embodiments, the piezoelectric sound generating unit 320A may be installed on the outer surface of the side wall 341A and connected to the side wall 341A, and at least a portion of the structure of the piezoelectric sound generating unit 320A may be in direct contact with the user's face area, so that the mechanical vibrations of the piezoelectric sound generating unit 320A can be transmitted directly to the user's face area. The inner surface of the side wall 341A is the side that contacts the housing space of the side wall 341A, and accordingly, the outer surface of the side wall 341A is the side that is away from the housing space of the side wall 341A. In some embodiments, a hole is formed in the side wall 341A, the hole penetrates the side wall 341A, and the edge of the piezoelectric element is connected to the corresponding hole wall of the hole. In some embodiments, the side wall of the housing 340A where the piezoelectric element is located may be covered with a protective layer (e.g., a silicone layer) to protect the piezoelectric element and at the same time improve the comfort of the user when wearing it. In some embodiments, the connection between the piezoelectric sound generating unit 320A and the side wall 341A may be achieved by a local connection between the unit and the side wall 341A. For example, by connecting the edge or middle portion of the piezoelectric sound generating unit 320A to the side wall 341A, a large portion of the piezoelectric sound generating unit 320A is fixed to the side wall 341A, thereby avoiding any influence on the vibration of the piezoelectric sound generating unit 320A.In some embodiments, the piezoelectric element of the piezoelectric sound generating unit 320A may have a plate-like structure, and the piezoelectric element may have a plate-like structure of a regular or arbitrary irregular shape such as a rectangle, circle, ring, ellipse, semicircle, or polygon. Taking the case where the piezoelectric element has a circular plate-like structure as an example, the edge of the piezoelectric element is connected to the side wall 341A, and the main body portion of the piezoelectric element (the portion other than the edge region) is suspended from the side wall 341A. Taking the case where the piezoelectric element has an annular plate-like structure as an example, the outer edge of the piezoelectric element is connected to the side wall 341A, and the main body portion of the piezoelectric element (the portion other than the outer edge region) is suspended from the side wall 341A, or, if the dimensions of the piezoelectric element are larger than the side wall 341A, the piezoelectric element may be fitted onto the side wall 341A.

[0027] In some embodiments, when the piezoelectric sound generation unit 320A is mainly used for bone conduction sound wave output, the angle between the vibration direction of the piezoelectric sound generation unit 320A and the vibration direction of the bone conduction sound generation unit 310A may be within the angular range of -45° to 45°. This minimizes the cancellation between the sound wave vibrations generated by the piezoelectric sound generation unit 320A and the sound waves generated by the bone conduction sound generation unit 310A, thereby improving the output capability and output effect of the bone conduction sound waves. In some embodiments, the angle between the vibration direction of the piezoelectric sound generation unit 320A and the vibration direction of the bone conduction sound generation unit 310A may be within the angular range of -20° to 20°. In some embodiments, the vibration direction of the piezoelectric sound generation unit 320A and the vibration direction of the bone conduction sound generation unit 310A may be approximately the same. In some embodiments, the vibration direction of the piezoelectric sound generation unit 320A and the vibration direction of the bone conduction sound generation unit 310A may be the same.

[0028] Figure 3B is a schematic diagram of the configuration of an acoustic output device according to some other embodiments of this specification. The overall structure of the acoustic output device 300B shown in Figure 3B and the acoustic output device 300A shown in Figure 3A are almost the same, the main difference being that the piezoelectric sound generation unit 320B is positioned on the side opposite the side wall 341B. The vibrations generated by the piezoelectric sound generation unit 320B are transmitted to the housing 340B, and the housing 340B vibrates, causing the surrounding air to vibrate and generate air-conducted sound waves. As mentioned above, in this situation, the mechanical vibrations generated by the piezoelectric sound generation unit 320B may be transmitted through the housing 340B to the user's muscles, bones, blood, etc., generating bone-conducted sound waves. The housing 340B, bone-conducted sound generation unit 310B, and piezoelectric sound generation unit 320B shown in Figure 3B are similar in structure to the housing 340A, bone-conducted sound generation unit 310A, and piezoelectric sound generation unit 320A shown in Figure 3A, so their explanation is omitted here.

[0029] Taking the housing 340B as an example of a rectangular parallelepiped structure, in some embodiments, the piezoelectric sound generating unit 320B may be installed on a side wall 341B of the housing 340B that is opposite to or adjacent to it, and vibrations of the piezoelectric sound generating unit 320B can be partially transmitted to the side wall 341B of the housing 340B via the side wall 341B that is opposite to or adjacent to it, thereby generating bone conduction sound waves. In some embodiments, the piezoelectric sound generating unit 320B may be installed on the inner or outer surface of the side wall 341B of the housing 340B that is opposite to or adjacent to it, or it may be fitted onto the side wall 341B of the housing 340B that is opposite to or adjacent to it. Furthermore, when the piezoelectric sound generating unit 320B is located on a side wall 341B of the housing 340B that is opposite to or adjacent to it, vibrations of the piezoelectric sound generating unit 320B may also cause vibrations in the air around the piezoelectric sound generating unit 320B, potentially generating air conduction sound waves. Simultaneously, vibrations from the piezoelectric sound generating unit 320B are transmitted to the housing 340B, causing the housing 340B to vibrate and drive the surrounding air to vibrate, potentially generating air-conducted sound waves. In particular, when the piezoelectric sound generating unit 320B is located on the side wall of the housing 340B facing the side wall 341B, the mechanical vibrations generated by the piezoelectric sound generating unit 320B are transmitted to the side wall 341B, resulting in significant vibration loss. At this time, the vibrations of the piezoelectric sound generating unit 320B mainly cause vibrations in the air surrounding the piezoelectric sound generating unit 320B and the housing 340B, generating air-conducted sound waves. In some embodiments, the piezoelectric sound generating unit 320B may be installed at any other location in the housing 340B that does not come into contact with a person's face. For example, the piezoelectric sound generating unit 320B may be suspended within the housing space of the housing 340B, and the piezoelectric sound generating unit vibrates to drive the surrounding air to vibrate, generating air-conducted sound waves. In some embodiments, the housing 340B may be provided with sound guide holes (not shown in Figure 3B) to allow the piezoelectric sound generating unit 320B to radiate air-conducted sound waves generated within the housing space to the outside so that they can be received by a person's ear.In some embodiments, the piezoelectric sound generation unit 320B may include a piezoelectric element, a vibration transmission element, and a vibrating membrane, wherein one end of the piezoelectric element is connected to the housing 340B of the sound output device and the other end is suspended and installed within the housing space of the housing 340B, and the vibrating membrane is installed on the side of the housing 340B facing the human body, and the vibration transmission element is installed within the housing space of the housing 340B, with one end of the vibration transmission element connected to the piezoelectric element and the other end in contact with the vibrating membrane, and the piezoelectric element drives the vibrating membrane via the vibration transmission element to vibrate, which in turn drives the surrounding air to vibrate, thereby generating air-conducted sound waves that can be received by the human ear. In some embodiments, the vibrating membrane may be installed on a side wall adjacent to or opposite to the side wall 341B of the housing 340B, in which case the vibrating membrane may be considered as part of the side wall, or the vibrating membrane may be located within the housing space of the housing 340B, in which case the housing 340B may be provided with sound guide holes to radiate air-conducted sound waves generated by the piezoelectric sound generating unit 320B within the housing space to the outside so that they can be received by human ears. Hereinafter, various embodiments in which the piezoelectric sound generating unit 320B is mainly used for generating air-conducted sound waves will be described with reference to Figures 4 and 5.

[0030] Figure 4 is an illustrative structural diagram of a piezoelectric sound generation unit according to some embodiments of this specification. As shown in Figure 4, the piezoelectric sound generation unit 420 includes a piezoelectric element 421, one end of which is connected to the housing 440 of an acoustic output device, and the other end of which is suspended and installed within the housing space of the housing 440. A sound guide hole 442 is installed on the side of the housing 440 facing the human body, and the piezoelectric element 421 vibrates to drive and vibrate the surrounding air, thereby generating air-conducted sound waves, which are then radiated to the outside through the sound guide hole 442. The housing 440 shown in Figure 4 is similar to the housing 340A shown in Figure 3A, so its description is omitted here.

[0031] In some embodiments, the piezoelectric element 421 has a fixed end and a free end, respectively. The fixed end is the end of the piezoelectric element 421 that provides a fixing or support function to the other part. In some embodiments, during the vibration process of the piezoelectric element 421, the vibration intensity of the fixed end is smaller than that of the other part of the piezoelectric element 421 (e.g., the free end). As just one example, the fixed end may be a location in the piezoelectric element 421 where the vibration acceleration or acceleration level is less than a vibration acceleration threshold or acceleration level threshold. In some embodiments, the fixed end may be connected to a fixed position or structure on the sound output device. The fixed position or structure here may be a location or structure in the sound output device where the vibration acceleration or acceleration level is less than a vibration acceleration threshold or acceleration level threshold. The fixed end shown in Figure 4 is connected to the housing 440. The free end is the end of the piezoelectric element 421 that generates sound and is away from the fixed end and can vibrate more freely relative to the fixed end. The free end shown in Figure 4 is the suspended end of the piezoelectric element 421. In some embodiments, the piezoelectric element 421 may be a plate-shaped, strip-shaped structure or any other structure in which the length is greater than the width and thickness. For example, the piezoelectric element 421 may be a prismatic structure, where length is the dimension in the longitudinal direction (direction a in Figure 4), thickness is the dimension in the thickness direction (direction b in Figure 4), and width is the dimension in the width direction (which is also perpendicular to the longitudinal and thickness directions).

[0032] In some embodiments, the piezoelectric element 421 may include a piezoelectric layer 4211 and a base layer 4212. In some embodiments, the piezoelectric layer 4211 may be made of a piezoelectric material. In some embodiments, the material of the base layer 4212 may include, but is not limited to, metals, alloys, resins, glass fibers, and carbon fibers, or any combination thereof. In some embodiments, the piezoelectric layer 4211 and the base layer 4212 are installed overlapping in the thickness direction of the piezoelectric element 421. In some embodiments, the piezoelectric layer 4211 may be fixed to one side of the base layer 4212 by a physical method such as adhesive. In some embodiments, the piezoelectric element 421 may include two piezoelectric layers 4211 and a base layer 4212, and the two piezoelectric layers 4211 and the base layer 4212 are installed overlapping in the thickness direction of the piezoelectric element 421. In some embodiments, the piezoelectric element 421 may include multiple piezoelectric layers 4211, and the multiple piezoelectric layers 4211 and the base layer 4212 are installed overlapping.

[0033] In some embodiments, the sound duct 442 may be located at any other location on the housing 440 that does not come into contact with a person's face. For example, the sound duct 442 may be located on a side of the housing 440 adjacent to the side that comes into contact with a person's face. In some embodiments, the sound duct 442 connects the housing cavity of the housing 440 to the outside of the housing 440. In some embodiments, the sound duct 442 is installed through the side wall of the housing 440. In some embodiments, the sound duct 442 may have a regular or any irregular shape, such as a rectangle, circle, ring, ellipse, semicircle, polygon, or triangle.

[0034] In some embodiments, the piezoelectric sound generation unit 420 may include a plurality of different piezoelectric elements, each having a different resonant frequency, and piezoelectric elements having different resonant frequencies can output air-conducted sound waves in different frequency bands, thereby compensating for sound wave output in different frequency bands. For example, the piezoelectric sound generation unit 420 includes a third piezoelectric element and a fourth piezoelectric element, the third piezoelectric element having a resonant frequency of 7 kHz and being able to output air-conducted sound waves in the 4 kHz to 9 kHz range, the fourth piezoelectric element having a resonant frequency of 11 kHz and being able to output air-conducted sound waves in the 9 kHz to 12 kHz range, and the combination of the third piezoelectric element and the fourth piezoelectric element can compensate for sound wave output within the frequency range of 4 kHz to 12 kHz.

[0035] Figure 5 is an illustrative structural diagram of a piezoelectric sound generation unit according to some embodiments of this specification. As shown in Figure 5, the piezoelectric sound generation unit 520 includes a piezoelectric element 521, a vibration transmission element 522, and a vibrating membrane 550. The piezoelectric element 521 is installed with one end connected to the housing 540 of the sound output device and the other end suspended within the housing space of the housing 540. The vibrating membrane 550 is installed on the side of the housing 540 facing the human body. The vibration transmission element 522 is installed within the housing space of the housing 540. One end of the vibration transmission element 522 is connected to the piezoelectric element 521 and the other end is in contact with the vibrating membrane 550. The piezoelectric element 521 drives the vibrating membrane 550 via the vibration transmission element 522 to vibrate, and the vibrating membrane 550 drives the surrounding air to vibrate, generating air-conducted sound waves that can be received by the human ear. In some embodiments, the vibrating membrane 550 may be installed on the side wall of the housing 540, for example, on a side wall adjacent to or opposite to the side wall 341B shown in Figure 3B, in which case the vibrating membrane 550 may be considered as part of the side wall, and the air-conducted sound waves generated by the vibration of the vibrating membrane 550 can be transmitted directly to the outside. In some embodiments, the vibrating membrane 550 may be located within the housing space of the housing 540, in which case the housing 540 may be provided with sound guide holes to allow the piezoelectric sound generation unit 520 to radiate air-conducted sound waves generated within the housing space to the outside so that they can be received by human ears. The housing 540 and piezoelectric element 521 shown in Figure 5 are similar to the housing 440 and piezoelectric element 421 shown in Figure 4, so their description is omitted here.

[0036] In some embodiments, the circumferential side of the vibrating membrane 550 is connected to the housing 540. In some embodiments, the vibrating membrane 550 may be installed at any other location on the housing 540 that does not come into contact with the person's face, for example, the vibrating membrane 550 may be installed on a side of the housing 540 that is substantially perpendicular to the person's face.

[0037] In some embodiments, the vibrating membrane 550 and the piezoelectric element 521 are connected via a vibration transmission element 522. In some embodiments, one end of the piezoelectric element 521 may be connected to the side wall of the housing 540, and the end of the piezoelectric element 521 away from the housing 540 is connected to the vibration transmission element 522. In some embodiments, the polarization direction of the piezoelectric element 521 is perpendicular to the stress direction, and when the piezoelectric element 521 is subjected to an electric field perpendicular to its surface, the piezoelectric element 521 is subjected to stress along its length, at which time the piezoelectric layer of the piezoelectric element 521 deforms and drives the overall structure of the piezoelectric element 521 to deform, generating vibration along its polarization direction, the vibration transmission element 522 can extend along the polarization direction of the piezoelectric element 521, the piezoelectric element 521 vibrates due to the vibration transmission element 522, and the vibrating membrane 550 vibrates along the polarization direction of the piezoelectric element 521. In some embodiments, the vibration transmission element 522 may have a regular or irregular structure such as a rod, plate, strip, or spiral structure. In some embodiments, the piezoelectric sound generation unit 520 may not include the vibration transmission element 522, and the piezoelectric element 521 may have one end connected to the housing 540 of the sound output device and the other end in direct contact with the vibrating membrane 550, and the piezoelectric element 521 may directly drive and vibrate the vibrating membrane 550 to generate air-conducted sound waves.

[0038] In some embodiments, in order to avoid the vibration of the diaphragm 550 of the piezoelectric sound generation unit and the vibration of the bone conduction sound generation unit influencing each other due to vibration transmission by the housing 540, the vibration direction of the diaphragm 550 and the vibration direction of the bone conduction sound generation unit can be made perpendicular, where perpendicular can be understood as approximately perpendicular, and in some embodiments, the angle between the vibration direction of the diaphragm 550 and the vibration direction of the bone conduction sound generation unit may be within the angular range of 70° to 110°.

[0039] Hereinafter, various embodiments of the acoustic output device, which includes a bone conduction sound generation unit, a piezoelectric sound generation unit, and an air conduction sound generation unit, will be described with reference to Figures 6A and 6B.

[0040] Figure 6A is an exemplary structural diagram of an acoustic output device according to some embodiments of this specification. Figure 6B is an exemplary structural diagram of an acoustic output device according to some further embodiments of this specification. As shown in Figures 6A and 6B, the acoustic output device 600 includes a housing 640, a bone conduction sound generation unit 610, a piezoelectric sound generation unit 620, and an air conduction sound generation unit 630, wherein the air conduction sound generation unit 630 is used to output low-frequency air conduction sound waves, the bone conduction sound generation unit 610 is used to output intermediate-frequency bone conduction sound waves, and the housing cavity of the housing 640 has two independent keys The cavity is partitioned, and the bone conduction sound generation unit 610 is installed alone in one cavity, while the piezoelectric sound generation unit 620 and the air conduction sound generation unit 630 are arranged in parallel (as shown in Figure 6A) or stacked (as shown in Figure 6B) in a separate cavity, thereby preventing the vibrations of the bone conduction sound generation unit 610 from being transmitted by the air in the housing 640 and affecting the air conduction sound waves of the piezoelectric sound generation unit 620 and the air conduction sound generation unit 630. For more information on the air conduction sound generation unit 630, see Figure 1; for more information on the bone conduction sound generation unit 610 and the housing 640, see Figures 1, 3A, and 3B; and for more information on the piezoelectric sound generation unit 620, see Figures 1 and 3B to 5.

[0041] In some embodiments, the air-conducted sound generation unit 630 may include a diaphragm that vibrates based on an audio signal, and the diaphragm drives the air inside the housing 640 of the sound output device 600 to vibrate, thereby generating air-conducted sound waves. These air-conducted sound waves inside the housing 640 are radiated to the outside through sound ducts and can be received by human ears. In some embodiments, the air-conducted sound generation unit 630 may further include a voice coil and a magnetic circuit structure, the diaphragm and the magnetic circuit structure are connected via the voice coil, the internal magnetic field of the magnetic circuit structure changes in response to an audio signal, the voice coil vibrates due to the action of the magnetic circuit structure, and the diaphragm vibrates in response to the vibration of the voice coil. Note that the diaphragm of the air-conducted sound generation unit 630 and the diaphragm of the piezoelectric sound generation unit 620 in some embodiments are not the same diaphragm, but rather diaphragms that each has in order to realize the transmission of air-conducted sound waves.

[0042] In some embodiments, to reduce the mutual influence between the vibration of the bone conduction sound generation unit 610 and the vibration of the air conduction sound generation unit due to vibration transmission by the housing 640, the angle between the vibration direction of the diaphragm and the vibration direction of the bone conduction sound generation unit 610 may be within an angular range of 70° to 110°. In some embodiments, the vibration direction of the diaphragm and the vibration direction of the bone conduction sound generation unit 610 may be approximately perpendicular. In some embodiments, the vibration direction of the diaphragm and the vibration direction of the bone conduction sound generation unit 610 may be perpendicular. In some embodiments, the piezoelectric sound generation unit 620 vibrates to generate air conduction sound waves, and the vibration direction of the piezoelectric sound generation unit 620 and the vibration direction of the air conduction sound generation unit may be made to coincide. This improves the output capability and output effect of the air conduction sound waves by minimizing the cancellation of the sound wave vibrations generated by the piezoelectric sound generation unit 620 and the sound waves generated by the air conduction sound generation unit. In some embodiments, the vibration direction of the piezoelectric sound generation unit 620 and the vibration direction of the air conduction sound generation unit 630 may be approximately the same. In some embodiments, the angle between the vibration direction of the piezoelectric sound generation unit 620 and the vibration direction of the air conduction sound generation unit 630 may be within the angular range of -20° to 20°.

[0043] In some embodiments, the piezoelectric sound generating unit 620 and the air-conducted sound generating unit 630 may be arranged in any other configuration, for example, they may be arranged diagonally.

[0044] In some embodiments, the acoustic output device 600 includes a housing 640, a bone conduction sound generation unit 610, a piezoelectric sound generation unit 620, and an air conduction sound generation unit 630, wherein the air conduction sound generation unit 630 is mainly used to output low-frequency air conduction sound waves, the bone conduction sound generation unit 610 is mainly used to output intermediate-frequency bone conduction sound waves, and the piezoelectric sound generation unit 620 is mainly used to output high-frequency bone conduction sound waves. The housing cavity of the housing 640 is divided into two independent cavities, with the bone conduction sound generation unit 610 and the piezoelectric sound generation unit 620 installed in one cavity and the air conduction sound generation unit 630 placed in the other cavity, thereby preventing vibrations from the piezoelectric sound generation unit 620 and the bone conduction sound generation unit 610 from being transmitted through the air inside the housing 640 and affecting the air conduction sound waves of the air conduction sound generation unit 630. For more details regarding the air conduction sound generation unit 630, please refer to Figures 1, 6A, and 6B. For more details regarding the piezoelectric sound generation unit 620, the bone conduction sound generation unit 610, and the housing 640, please refer to Figures 1, 3A, and 3B.

[0045] In some embodiments, the vibration direction of the diaphragm and the vibration direction of the bone conduction sound generation unit 610 may be perpendicular to each other in order to avoid the vibrations of the bone conduction sound generation unit 610 and the vibrations of the air conduction sound generation unit influencing each other due to vibration transmission by the housing 640. In some embodiments, the piezoelectric sound generation unit 620 vibrates to generate bone conduction sound waves, and the vibration direction of the piezoelectric sound generation unit 620 and the vibration direction of the bone conduction sound generation unit 610 may be aligned, thereby improving the output capability and output effect of the bone conduction sound waves by minimizing the cancellation of the sound wave vibrations generated by the piezoelectric sound generation unit 620 and the sound waves generated by the bone conduction sound generation unit 610.

[0046] The following describes various embodiments of the bone conduction sound generation unit with reference to Figures 7A to 8A.

[0047] Figures 7A and 7B are schematic diagrams of an acoustic output device according to some embodiments of this specification. As shown in Figures 7A and 7B, the acoustic output device 700 includes a housing 740, an air conduction sound generation unit 730, and a bone conduction sound generation unit 710. The housing 740 is similar to the housing 340A shown in Figure 3A. The air conduction sound generation unit 730 is installed on the side wall of the housing 740, and the bone conduction sound generation unit 710 is installed in a housing cavity, and the vibration direction of the air conduction sound generation unit 730 and the vibration direction of the bone conduction sound generation unit 710 are substantially perpendicular. Here, substantially perpendicular means that the angle between the vibration direction of the air conduction sound generation unit 730 and the vibration direction of the bone conduction sound generation unit 710 may be within a specific angular range. In some embodiments, the specific angular range may be 70° to 110°. Preferably, the specific angular range may be 80° to 100°. In some embodiments, the diaphragm of the air-conducted sound generation unit 730 may be located on a side wall adjacent to or opposite to the side of the housing 740 that contacts a person's face. For example, a hole may be formed in the housing 740, and the edge of the diaphragm may be connected to the corresponding hole wall of the hole. In this case, the diaphragm of the air-conducted sound generation unit 730 may be considered as part of the side wall of the housing 740, and the air-conducted sound waves output by the air-conducted sound generation unit 730 can be transmitted directly to the outside. Alternatively, for example, the diaphragm of the air-conducted sound generation unit 730 may be located within the housing cavity of the housing 740. Accordingly, one or more sound ducts (not shown) may be provided in the housing 740, and the sound ducts may be used to transmit the air-conducted sound waves generated by the air-conducted sound generation unit 730 to the outside.In some embodiments, the bone conduction sound generation unit 710 includes a magnetic circuit system 711, a coil 712, and a vibration transmission sheet 713A, the magnetic circuit system 711 includes a magnet assembly 7111 and a magnetic flux conduction cover 7112, the coil 712 is fitted outside the magnet assembly 7111 around an axis parallel to the vibration direction of the bone conduction sound generation unit 710 (direction c shown in Figure 7A), the magnetic flux conduction cover 7112 is circumferentially positioned outside the coil 712 along the vibration direction of the bone conduction sound generation unit 710, the magnetic flux conduction cover 7112, the coil 712, and the magnet assembly 7111 are spaced apart in a direction perpendicular to the vibration direction, a magnetic gap is formed between the inner wall of the magnetic flux conduction cover 7112 and the outside of the magnet assembly 7111, and in the vibration direction, the vibration transmission sheet 713A elastically supports the magnet assembly 7111 from one side. The air-conducted sound generation unit 730 may be replaced with a piezoelectric sound generation unit, in which case the position and structure of the piezoelectric sound generation unit in the acoustic output device 700 will be similar to that of the piezoelectric sound generation unit 320A shown in Figure 3A. Alternatively, the acoustic output device 700 may further include a piezoelectric sound generation unit, in which case the piezoelectric sound generation unit may be located on the side wall of the housing 740 that contacts the person's face (the side that abuts the person's face), on the side wall adjacent to or opposite the side of the housing 740 that abuts the person's face, or within the housing cavity of the housing 740. For the position and structure of the piezoelectric sound generation unit in the acoustic output device 700, refer to the piezoelectric sound generation units shown in Figures 3B, 4, and 5.

[0048] In some embodiments, the side of the housing 740 connected to the bone conduction sound generation unit 710 may be in contact with the user's face area, and vibrations generated by the bone conduction sound generation unit 710 can be transmitted to the user through the housing 740. In some embodiments, the housing 740 may be connected to the magnet assembly 7111 via a vibration transmission sheet 713A, thereby suspending the magnet assembly 7111 within the housing cavity of the housing 740. For example, the vibration transmission sheet 713A and the magnet assembly 7111 are positioned along the direction of vibration, and the side of the vibration transmission sheet 713A perpendicular to the direction of vibration is connected to the end of the magnetic flux conduction cover 7112 perpendicular to the direction of vibration, thereby securing the magnet assembly 7111. In some embodiments, the magnetic flux conduction cover 7112 may be connected to the magnet assembly 7111, thereby securing the magnetic flux conduction cover 7112 to the magnet assembly 7111. In some embodiments, the vibration transmission sheet 713A and the magnetic flux transmission cover 7112 are arranged along the direction of vibration, and the side of the vibration transmission sheet 713A perpendicular to the direction of vibration is connected to the end of the magnetic flux transmission cover 7112 perpendicular to the direction of vibration. In some embodiments, the acoustic output device 700 may further include a vibration transmission sheet 713B, the side of the vibration transmission sheet 713B perpendicular to the direction of vibration is connected to the end of the magnet assembly 7111 perpendicular to the direction of vibration, and another side of the vibration transmission sheet 713B perpendicular to the direction of vibration is connected to the side wall of the housing 740 perpendicular to the direction of vibration. The acoustic output device 700 may include only the vibration transmission sheet 713A or only the vibration transmission sheet 713B, or it may include both the vibration transmission sheet 713A and the vibration transmission sheet 713B simultaneously, thereby enhancing the stability of the magnet assembly 7111 during vibration. In some embodiments, the vibration transmission sheet may also be located between the flux conduction cover 7112 and the housing 740, as shown in Figure 7B, where the vibration transmission sheet 713C has an annular structure, with the inner ring side of the vibration transmission sheet 713C connected to the circumferential side of the flux conduction cover 7112 and the outer circumferential side of the vibration transmission sheet 713C connected to the housing 740, thereby enabling the fixing of the magnet assembly 7111 to the flux conduction cover 7112.

[0049] In some embodiments, the magnetic flux conduction cover 7112 is a housing structure with an open opening at one end, the magnet assembly 7111 is located inside the magnetic flux conduction cover 7112, one end of the magnet assembly 7111 is connected to the bottom wall opposite the opening of the magnetic flux conduction cover 7112, and the side wall of the magnet assembly 7111 and the side wall of the housing 740 are spaced apart. In some embodiments, there is a gap between the inner wall of the magnetic flux conduction cover 7112 and the side wall of the magnet assembly 7111 along a direction perpendicular to the vibration direction of the bone conduction sound generation unit 710, a magnetic gap is formed on the circumferential side of the magnetic flux conduction cover 7112 and the magnet assembly 7111, one end of the coil 712 is connected to the side of the housing 740 that contacts the person's face and the other end is inserted into the magnetic gap, and there is a gap between the other end of the coil 712 and the magnetic flux conduction cover 7112 along the vibration direction, thereby ensuring that relative motion can be realized between the magnetic circuit system 711 and the coil 712.

[0050] Figure 8A is a schematic diagram of an acoustic output device according to some embodiments of this specification. As shown in Figure 8A, the acoustic output device 800 includes a housing 840, an air conduction sound generation unit 830, and a bone conduction sound generation unit 810. The air conduction sound generation unit 830 is similar to the air conduction sound generation unit 730 shown in Figure 7A, and therefore its description is omitted here. A housing cavity for housing the bone conduction sound generation unit 810 may be formed inside the housing 840. The bone conduction sound generation unit 810 may include a magnetic circuit system, a coil 812, a first vibration transmission sheet 813, and a second vibration transmission sheet 814. The magnetic circuit system includes a magnet assembly 8111 and a magnetic flux conduction cover 8112. The coil 812 is fitted outside the magnet assembly 8111 around an axis parallel to the vibration direction of the bone conduction sound generation unit 810 (see Figure 8A), and the magnetic flux conduction cover 8112 transmits vibrations of the bone conduction sound generation unit 810. The magnetic flux conduction cover 8112 and the magnet assembly 8111 are fitted onto the coil 812 along the direction of motion, spaced apart in a direction perpendicular to the direction of vibration, a magnetic gap is formed between the inner wall of the magnetic flux conduction cover 8112 and the outer side of the magnet assembly 8111, and in the direction of vibration, the first vibration transmission sheet 813 and the second vibration transmission sheet 814 elastically support the magnet assembly 8111 from opposite sides of the magnet assembly 8111, respectively. In the embodiments herein, the magnet assembly 8111 is elastically supported on opposite sides in the direction of vibration of the bone conduction sound generation unit 810, thereby minimizing the chance of the magnet assembly 8111 and the magnetic flux conduction cover 8112 being attracted or repelled by magnetic force and thus helping to improve the vibration stability of the bone conduction sound generation unit 810.The air-conducted sound generation unit 830 may be replaced with a piezoelectric sound generation unit (for example, the piezoelectric sound generation unit 420 shown in Figure 4 or the piezoelectric sound generation unit 520 shown in Figure 5), and the piezoelectric sound generation unit may include a piezoelectric element and a vibrating membrane connected to the piezoelectric element. The piezoelectric element can drive the vibrating membrane to vibrate and generate air-conducted sound waves, and by adjusting the parameters of the piezoelectric element itself (for example, structure, length, width, thickness, material, etc.), the piezoelectric sound generation unit can be made to output air-conducted sound waves mainly in the low-frequency band so as to be similar to the air-conducted sound generation unit 830. The position and structure of the piezoelectric sound generation unit in the acoustic output device 800 are similar to those of the piezoelectric sound generation unit 320A shown in Figure 3A. In the embodiment shown in Figure 8A, the acoustic output device 800 further includes a piezoelectric sound generation unit 880, which is located on a vibrating panel 860. The piezoelectric element of the piezoelectric sound generation unit 880 vibrates in response to a driving voltage, and this vibration is transmitted to the human face along with the vibration of the vibrating panel 860, allowing the user to hear bone-conducted sound waves. By adjusting the parameters of the piezoelectric element itself (e.g., structure, length, width, thickness, material, etc.), the piezoelectric sound generation unit is made to output bone-conducted sound waves mainly in the high-frequency band. In some embodiments, the piezoelectric sound generation unit 880 may be located on a side wall adjacent to or facing the vibrating panel of the housing 840, or it may be located within the housing cavity of the housing 840. For the position and structure of the piezoelectric sound generation unit 880 in the acoustic output device 800, refer to the piezoelectric sound generation unit shown in Figures 3B, 4, and 5. The air conduction sound generation unit 830 is mainly used for low frequency output (e.g., 20Hz to 500Hz), the bone conduction sound generation unit 810 is mainly used for intermediate frequency output (e.g., 500Hz to 6kHz), and the piezoelectric sound generation unit 880 is mainly used for high frequency output (e.g., 6kHz to 20kHz). As a result, the sound output by the sound output device 800 can cover a wide range from low to high frequencies, and the sound output intensity is improved across the entire frequency range, effectively improving the overall sound quality.

[0051] In some embodiments, the acoustic output device 800 may include a vibrating panel 860, which may be connected to a bone conduction sound generation unit 810. The vibrating panel 860 is used to transmit the mechanical vibrations generated by the bone conduction sound generation unit 810 to the person's face and act on the user's auditory nerve through the user's skin, bones, and / or tissues to form bone conduction sound waves. The housing 840 may be a columnar structure (e.g., a rectangular parallelepiped structure, a cylindrical structure), spherical, a platform, or any irregular shape or combination thereof, and is not limited to the shape shown in the figure.

[0052] In some embodiments, the acoustic output device 800 may further include a vibration damping sheet 870. The bone conduction sound generation unit 810 may be suspended within the housing cavity of the housing 840 via the vibration damping sheet 870. The vibration panel 860 does not have to be in contact with the housing 840, in which case, the presence of the vibration damping sheet 870 reduces, or even prevents from, the transmission of mechanical vibrations generated by the bone conduction sound generation unit 810 to the housing 840, thereby somewhat preventing the housing 840 from driving the air outside the acoustic output device 800 to vibrate, and helping to reduce sound leakage from the acoustic output device 800. Furthermore, since the vibration panel 860 and the elements rigidly connected to the vibration panel 860 are elastically connected to the housing 840 and the elements rigidly connected to the housing 840 by the vibration damping sheet 870, they can be considered almost as a resonant system. In this case, by installing additional elements (e.g., air conduction sound generation unit, piezoelectric sound generation element, circuit element, microphone, etc.) added to the bone conduction sound generation unit 810 in the housing 840, it is possible that vibration transmission between the additional elements and the vibration panel 860 can be suppressed in a specific frequency band (e.g., a resonant frequency higher than that of the resonant system). In other words, the influence of the additional elements on the vibration of the vibration panel 860 can be reduced. This ensures that the sensitivity of the bone conduction sound generation unit 810 in the acoustic output device 800 is not affected or is not significantly affected by the additional elements in a specific frequency band, ensuring that the acoustic output device 800 has a good acoustic output effect over a wide frequency range, and improving the user's auditory experience.

[0053] In some embodiments, the housing 840 may have an open end, and the vibrating panel 860 may be installed outside the housing 840 and facing the open end, that is, the edge of the vibrating panel 860 is not connected to the open end of the housing 840, and a connecting rod 861 is installed between the vibrating panel 860 and the bone conduction sound generating unit 810, with one end of the connecting rod 861 connected to the bone conduction sound generating unit 810 and the other end passing through the open end of the housing 840 and connected to the vibrating panel 860, thereby reducing sound leakage of the acoustic output device 800 by preventing the vibrating vibrating panel 860 and bone conduction sound generating unit 810 from contacting the housing 840. In some embodiments, a vibration damping sheet 870 may be connected between the connecting rod 861 and the housing 840 to achieve suspension of the vibrating panel 860 and bone conduction sound generating unit 810.

[0054] In some embodiments, the bone conduction sound generation unit 810 may include a bracket 8140, and the vibration panel 860 may be connected to the bracket 8140. In some embodiments, as shown in Figure 8A, the bracket 8140 may be connected to the end of a connecting rod 861 away from the vibration panel 860. The bracket 8140 may be connected to the magnetic circuit system via a first vibration transmission sheet 813 so as to suspend the magnetic circuit system within the housing cavity of the housing 840. In some embodiments, a vibration damping sheet 870 may connect the bracket 8140 to the housing 840 so as to suspend the bone conduction sound generation unit 810 within the housing cavity of the housing 840.

[0055] In some embodiments, the coil 812 may include a first coil 8121 and a second coil 8122. In some embodiments, the first coil 8121 may be inserted into the magnetic gap of the magnetic circuit system from the side adjacent to the vibration panel 860 along the vibration direction, and the second coil 8122 may be inserted into the magnetic gap of the magnetic circuit system from the side away from the vibration panel 860 along the vibration direction. In some embodiments, to simplify the assembly process, the first coil 8121 and the second coil 8122 may be inserted together into the magnetic gap of the magnetic circuit system from the side adjacent to the vibration panel 860. In some embodiments, the bone conduction sound generation unit 810 may further include a retaining part for holding the shape of the first coil 8121 and the second coil 8122. For example, the first coil 8121 and the second coil 8122 may be in a single integrated structure. Specifically, the first coil 8121 and the second coil 8122 can be formed into a single integrated structure by winding them onto a shape-retaining material and then adhering them to the outside of the first coil 8121 and the second coil 8122 using a retaining part (e.g., a retaining material such as high-temperature tape). Since the first coil 8121 and the second coil 8122, fixed to the retaining part, extend from the same side of the vibration panel 860 into the magnetic gap of the magnetic circuit system, the coil assembly process is simplified. In some embodiments, the two coils are formed by winding the same wire, or parts of the two coils are connected, so that there are only two lead wires for the inlet and outlet of the two coils, simplifying wiring and facilitating electrical connections with subsequent structures.

[0056] In some embodiments, in the direction of vibration, the opposite edge regions 8131 of the first vibration transmission sheet 813 are connected to the side of the bracket 8140 that is close to the magnetic circuit system and the side of the magnetic flux conduction cover 8112 that is close to the bracket 8140, respectively. The edge region 8141 of the second vibration transmission sheet 814 is connected to the side of the magnetic flux conduction cover 8112 that is away from the bracket 8140. In some embodiments, the magnetic flux conduction cover 8112 may be a cylindrical structure with open ends. In some embodiments, the magnetic flux conduction cover 8112 may be a sealed structure to prevent sound generated by the magnetic circuit system from leaking to the outside.

[0057] In some embodiments, the magnet assembly 8111 may include a magnet 81111, a first magnetic flux conduction plate 81112, and a second magnetic flux conduction plate 81113, the first magnetic flux conduction plate 81112 and the second magnetic flux conduction plate 81113 being located on opposite sides of the magnet 81111 in the vibration direction of the bone conduction sound generation unit 810. The first vibration transmission sheet 813 can support the magnet assembly 8111 from the side of the first magnetic flux conduction plate 81112 away from the second magnetic flux conduction plate 81113, and the second vibration transmission sheet 814 can support the magnet assembly 8111 from the side of the second magnetic flux conduction plate 81113 away from the first magnetic flux conduction plate 81112. In some embodiments, the central region 8132 of the first vibration transmission sheet 813 is connected to the side of the first flux conduction plate 81112 away from the second flux conduction plate 81113, and the central region 8142 of the second vibration transmission sheet 814 is connected to the side of the second flux conduction plate 81113 away from the first flux conduction plate 81112. In some embodiments, the corners of the first flux conduction plate 81112 and / or the second flux conduction plate 81113 away from the magnet 81111 may be chamfered. For example, by chamfering the opposite corners of the first flux conduction plate 81112 and the second flux conduction plate 81113 (i.e., the corners away from the magnet 81111), the distribution of the magnetic field formed by the magnetic circuit system can be adjusted and the magnetic field can be made more concentrated. In some embodiments, in the vibration direction of the bone conduction sound generation unit 810, the position at half the height of the first coil 8121 and the position at half the thickness of the side parallel to the vibration direction of the first magnetic flux conduction plate 81112 may be at the same height, and the position at half the height of the second coil 8122 and the position at half the thickness of the side parallel to the vibration direction of the second magnetic flux conduction plate 81113 may be at the same height. In this way, the magnetic field can be concentrated in the rectangular portions of the first magnetic flux conduction plate 81112 and / or the second magnetic flux conduction plate 81113, excluding the chamfered portions.

[0058] In some embodiments, the magnetic flux conduction cover 8112 may be connected to the bracket 8140, so the bracket 8140 may be connected to the housing 840 via the vibration damping sheet 870 to suspend the bone conduction sound generation unit 810 within the housing cavity of the housing 840. At this time, both sides of the edge region 8131 of the first vibration transmission sheet 813 perpendicular to the direction of vibration may be connected to the bracket 8140 and the magnetic flux conduction cover 8112, respectively, and the side of the edge region 8141 of the second vibration transmission sheet 814 perpendicular to the direction of vibration may be connected to the magnetic flux conduction cover 8112, and the vibration panel 860 may be connected to the bracket 8140, with a certain gap between it and the open end of the housing 840, thereby ensuring that the vibration of the vibration panel 860 is not affected by the housing 840. In some embodiments, the housing 840 and the vibration panel 860 may be connected by an elastic structure such as an elastic silicone member, thereby achieving isolation of the housing 840 from the outside, preventing water, dust, and other impurities from entering, while simultaneously ensuring that the vibration of the vibration panel 860 is not affected.

[0059] As an alternative embodiment of the magnet assembly 8111, as shown in Figure 8B, the magnet assembly 8111 may include a first magnet 8111a and a second magnet 8111b stacked and installed along the vibration direction, wherein the magnetization directions of the first magnet 8111a and the second magnet 8111b are different, and the first vibration transmission sheet 813 (shown in Figure 8A) can support the magnet assembly 8111 from the side of the first magnet 8111a away from the second magnet 8111b, and the second vibration transmission sheet 814 (shown in Figure 8A) can support the magnet assembly 8111 from the side of the second magnet 8111b away from the first magnet 8111a. In some embodiments, the central region 8132 (shown in Figure 8A) of the first vibration transmission sheet 813 is connected to the side of the first magnet 8111a away from the second magnet 8111b, and the central region 8142 (shown in Figure 8A) of the second vibration transmission sheet 814 is connected to the side of the second magnet 8111b away from the first magnet 8111a. In some embodiments, the magnet assembly 8111 may include a flux conduction plate 8111c interposed between the first and second magnets. In some embodiments, the number of coils 812 may be one or three. If there is one coil 812, the coil (e.g., the first coil 812a) overlaps with the side surface of the flux conduction plate 8111c when orthographically projected onto the outer surface of the magnet assembly 8111 along a direction perpendicular to the vibration direction. If there are three coils, for example, the coils may include a first coil 812a, a second coil 812b, and a third coil 812c, where the first coil 812a, the second coil 812b, and the third coil 812c are distributed at intervals along the direction of vibration, the first coil 812a overlaps with the side surface of the magnetic flux conducting plate 8111c when projected orthogonally onto the outer surface of the magnet assembly 8111 in a direction perpendicular to the direction of vibration, the second coil 812b overlaps with the side surface of the first magnet 8111a when projected orthogonally onto the outer surface of the magnet assembly 8111 in a direction perpendicular to the direction of vibration, and the third coil 812c overlaps with the side surface of the second magnet 8111b when projected orthogonally onto the outer surface of the magnet assembly 8111 in a direction perpendicular to the direction of vibration.In some embodiments, the magnetization directions of the first magnet 8111a and the second magnet 8111b are opposite and both are perpendicular to the surface of the magnetic flux conducting plate 8111c facing either the first magnet 8111a or the second magnet 8111b.

[0060] Figure 9 is a schematic diagram of an acoustic output device according to some embodiments of this specification. As shown in Figure 9, the acoustic output device 900 may include a housing 911, a vibrating panel 913, and a bone conduction sound generation unit 930. In some embodiments, the housing 911 has an open end and a hollow structure, and the vibrating panel 913 is located at the open end of the housing 911 and forms a housing cavity for housing the housing 911 and the bone conduction sound generation unit 930. In some embodiments, the bone conduction sound generation unit 930 may include a magnetic circuit system, a coil 940, a first vibration transmission sheet 925, and a second vibration transmission sheet 926, the magnetic circuit system including a magnet assembly 931 and a magnetic flux conduction cover 932, the coil 940 being fitted to the outside of the magnet assembly 931 around an axis parallel to the vibration direction of the bone conduction sound generation unit 930 (see Figure 9), the magnetic flux conduction cover 932 being fitted to the coil 940 along the vibration direction of the bone conduction sound generation unit 930, the magnetic flux conduction cover 932 and the magnet assembly 931 being spaced apart in a direction perpendicular to the vibration direction, a magnetic gap being formed between the inner wall of the magnetic flux conduction cover 932 and the outside of the magnet assembly 931, and in the vibration direction, the first vibration transmission sheet 925 and the second vibration transmission sheet 926 elastically support the magnet assembly 931 from opposite sides of the magnet assembly 931, respectively. In the embodiments herein, the magnet assembly 931 is elastically supported on opposite sides in the direction of vibration of the bone conduction sound generation unit 930, so as to be free from abnormal vibrations such as obvious shaking, thereby helping to improve the vibration stability of the bone conduction sound generation unit 930. In some embodiments, the coil 940 may include a first coil 941 and a second coil 942, the first coil 941 and the second coil 942 located within the magnetic gap of the magnetic circuit system and spaced apart in the direction of vibration. For specific structures and positions of the first coil 941 and the second coil 942, refer to Figure 8A and its corresponding contents, which are omitted here.

[0061] In some embodiments, the flux conduction cover 932 is rigidly connected to the housing 911 or the vibration panel 913, and the circumferential sidewall of the flux conduction cover 932 away from the magnet assembly 931 fits into the inner wall of the housing 911, thereby making full use of the internal space of the housing 911 and helping to achieve miniaturization of the acoustic output device. In other embodiments of the present application, it can be understood that the flux conduction cover 932 may be rigidly connected to the housing 911 or the vibration panel 913 by other fixing structures. In some embodiments, any one edge region of the first vibration transmission sheet 925 and the second vibration transmission sheet 926 may be connected to the open end of the housing 911 by one or a combination of assembly methods such as locking and bonding, and the vibration panel 913 is connected to the open end of the housing 911 to form a sealed cavity. In some embodiments, the side of any one of the first vibration transmission sheet 925 and the second vibration transmission sheet 926 adjacent to the vibration panel 913 is connected to the vibration panel 913, and the vibration panel 913 is connected to the open end of the housing 911. In some embodiments, the vibration panel 913 and the housing 911 may be made of the same material and integrally molded. In some embodiments, the vibration panel 913 and the housing 911 may be made of different materials and may be connected by one or a combination of assembly methods such as fastening and bonding. In some embodiments, the magnet assembly 931 may include a magnet 933, a first magnetic flux conduction plate 934, and a second magnetic flux conduction plate 935, the first magnetic flux conduction plate 934 and the second magnetic flux conduction plate 935, respectively, located on opposite sides of the magnet 933 in the vibration direction of the bone conduction sound generation unit 930. The first vibration transmission sheet 925 can support the magnet assembly 931 from the side of the first magnetic flux conduction plate 934 away from the second magnetic flux conduction plate 935, and the second vibration transmission sheet 926 can support the magnet assembly 931 from the side of the second magnetic flux conduction plate 935 away from the first magnetic flux conduction plate 934.For detailed information regarding the first vibration transmission sheet 925, the second vibration transmission sheet 926, the first magnetic flux conduction plate 934, the second magnetic flux conduction plate 935, and the magnet 933, you can refer to the first vibration transmission sheet 813, the second vibration transmission sheet 814, the first magnetic flux conduction plate 81112, the second magnetic flux conduction plate 81113, and the magnet 81111 shown in Figure 8A of this specification, and their explanation is omitted here.

[0062] In some embodiments, the sound output device 900 may further include a piezoelectric sound generating unit 920, which may be located on the vibration panel 913. For example, the piezoelectric sound generating unit 920 may be located on the side of the vibration panel 913 that contacts a person's face. Alternatively, for example, the piezoelectric sound generating unit 920 may be located on the side of the vibration panel 913 away from the side that contacts a person's face. Furthermore, for example, the piezoelectric sound generating unit 920 may be fitted into the vibration panel 913. In some embodiments, the piezoelectric sound generating unit 920 may further be located on the side walls of the housing 911, for example, on the side wall of the housing 911 facing the vibration panel 913 and on adjacent side walls. In some embodiments, the acoustic output device 900 may include an air-conducted sound generation unit 910, which may be located on the side of the corresponding side wall of the housing 911 away from the housing cavity, in which case the air-conducted sound waves emitted by the air-conducted sound generation unit 910 may be transmitted directly to the outside. In some embodiments, the air-conducted sound generation unit 910 may further be located inside the corresponding side wall of the housing 911, or the air-conducted sound generation unit 910 may be located within the housing cavity of the housing 911 and fixedly connected to the housing 911 by a fixing member, and further, a sound guide hole (not shown) may be formed in the housing 911, and the air-conducted sound waves output by the air-conducted sound generation unit 910 may be transmitted to the outside through the sound guide hole. For details of the piezoelectric sound generation unit 920 and the air-conducted sound generation unit 910, refer to Figures 1 to 5 of this specification. The air conduction sound generation unit 910 is mainly used for low frequency output (e.g., 20Hz to 500Hz), the bone conduction sound generation unit 930 is mainly used for intermediate frequency output (e.g., 500Hz to 6kHz), and the piezoelectric sound generation unit 920 is mainly used for high frequency output (e.g., 6kHz to 20kHz). As a result, the sound output by the sound output device 900 can cover a wide range from low to high frequencies, and the sound output intensity is improved across the entire frequency range, effectively improving the overall sound quality.

[0063] Figures 1 to 9 are for illustrative purposes only and do not limit the present application. Those skilled in the art can make various changes and modifications based on the description of this application. The beneficial effects that can be achieved will differ depending on the embodiment, but in different embodiments, the beneficial effects that can be achieved may be one or more of the above, or any other beneficial effects that can be achieved.

[0064] Having explained the basic concepts above, it will be clear to those skilled in the art that the above detailed disclosures are merely examples and do not limit the present application. Although not explicitly stated herein, those skilled in the art can make various changes, improvements, and modifications to the present application. These changes, improvements, and modifications are intended to be suggested by the present application and are therefore within the spirit and scope of the exemplary embodiments of the present application.

[0065] Furthermore, certain terms are used in this Application to describe the embodiments thereof. For example, “one embodiment,” “one embodiment,” and / or “several embodiments” mean certain features, structures, or properties relating to at least one embodiment of this Application. Therefore, it should be emphasized and understood that two or more references to “one embodiment,” “one embodiment,” or “one alternative embodiment” in different parts of this Specification do not necessarily refer to the same embodiment. Also, certain features, structures, or properties in one or more embodiments of this Application can be appropriately combined.

[0066] Furthermore, unless explicitly stated in the claims, the enumerated order, use of alphanumeric characters, or use of other names of the processing elements or sequences described herein does not limit the order of the procedures and methods of this application. While the above disclosure illustrates various examples that are currently considered useful embodiments of the invention, such details are for illustrative purposes only, and it should be understood that the attached claims are not limited to the disclosed embodiments, but rather are intended to cover all modifications and equivalent combinations within the spirit and scope of the embodiments of this application. For example, the system assembly described above may be implemented by hardware devices, but may also be implemented by software-only solutions, for example, by installing the described system on an existing server or mobile device.

[0067] Similarly, in the foregoing description of embodiments of the present application, various features may be grouped into a single embodiment, drawing, or description thereof for the purpose of simplifying the description of the disclosure and aiding in the understanding of embodiments of one or more inventions. However, such disclosure methods should not be interpreted as reflecting an intention that the subject matter of the present application requires more features than those enumerated in each claim. In fact, the features of an embodiment may be fewer than all the features of a single embodiment disclosed above.

[0068] In some embodiments, numbers are used to describe components and attributes, and it should be understood that in some examples, these numbers are modified by the modifiers “approximately,” “nearly,” or “substantial.” Unless otherwise specified, “approximately,” “nearly,” or “substantial” indicates that the numbers are allowed to vary by up to ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are all approximations that may vary depending on the characteristics required for a particular embodiment. In some embodiments, the numerical parameters should be rounded using standard rounding techniques, taking into account the specified number of significant figures. In some embodiments of this application, the numerical ranges and parameters used to determine their ranges are approximations, but in specific embodiments, such numbers are set as precisely as possible.

[0069] All patents, patent applications, published patent gazettes, and other materials such as articles, books, specifications, publications, and documents referenced herein are incorporated in their entirety by reference, with the exception of any prosecution history documents that are inconsistent with or contradict the content of this Application, and any documents that may have a limited effect on the broadest scope of the claims of this Application (currently or later relating to this Application). In the event of any inconsistency or contradiction between any description, definition, and / or use of terminology in the appendices to this Application and the content of this Application, the description, definition, and / or use of terminology in this Application shall prevail.

[0070] Finally, it should be understood that the embodiments in this application are merely for illustrating the principles of the embodiments herein. Other modifications may also be within the scope of this application. Therefore, alternative configurations of the embodiments herein may be considered, for example, consistent with the teachings herein, without limitation. Accordingly, the embodiments of this application are not limited to those explicitly introduced and described herein. [Explanation of symbols]

[0071] 100 Audio output device 110 Bone conduction sound generation unit 120 Piezoelectric Sound Generating Unit 130 Air-Conditioned Sound Generation Unit 421 Piezoelectric element 4211 Piezoelectric layer 4212 Base layer 440 Housing 442 sound channels 522 Vibration transmission component 550 Diaphragm 711 Magnetic Circuit System 712 Coil 7111 Magnet Assembly 7112 Magnetic flux conduction cover

Claims

1. A bone conduction sound generation unit that generates bone conduction sound waves transmitted to a person's ear via bone and having at least one resonant peak in a frequency range of 1 kHz or less, A piezoelectric sound generation unit that generates sound waves having at least one resonant peak in a frequency range of 6 kHz or higher, Includes an air-conducted sound generation unit that generates air-conducted sound waves having a resonant peak in a frequency range of 500 Hz or less, The piezoelectric sound generation unit includes a piezoelectric element and a vibrating membrane connected to the piezoelectric element, the piezoelectric element drives the vibrating membrane to vibrate and generate a second air-conducted sound wave, and the vibrating membrane is perpendicular to the vibration direction of the bone-conducted sound generation unit. Audio output device.

2. The sound output device according to claim 1, wherein the piezoelectric sound generating unit is positioned in the housing of the sound output device so as not to come into contact with a person's face, the mechanical vibrations generated by the piezoelectric sound generating unit are transmitted to the housing, and the piezoelectric sound generating unit or the housing generates sound waves.

3. The acoustic output device according to claim 1, wherein the air conduction sound generation unit includes a vibrating membrane, and the direction of vibration of the vibrating membrane is perpendicular to the direction of vibration of the bone conduction sound generation unit.

4. The sound output device according to claim 1 or 3, wherein the piezoelectric sound generating unit and the air conduction sound generating unit are arranged in stacked or in parallel, and the vibration direction of the air conduction sound generating unit is perpendicular to the vibration direction of the bone conduction sound generating unit.

5. The acoustic output device according to any one of claims 1 to 3, wherein the bone conduction sound generation unit and the piezoelectric element are driven and vibrated by the same excitation voltage.

6. The acoustic output device according to claim 5, further comprising a boost circuit for boosting the excitation voltage that drives the piezoelectric element.

7. The acoustic output device according to claim 1, further comprising a frequency division circuit, the frequency division circuit performing frequency division based on a first crossover frequency to generate a signal in a first frequency range and a signal in a second frequency range, the signal in the first frequency range driving the bone conduction sound generation unit, and the signal in the second frequency range driving the piezoelectric sound generation unit.

8. The sound output device according to any one of claims 1 to 3, wherein the bone conduction sound generation unit includes a magnetic circuit system, a coil, and a vibration transmission sheet, the magnetic circuit system includes a magnet assembly, the coil is fitted outside the magnet assembly around an axis parallel to the vibration direction of the bone conduction sound generation unit, and in the vibration direction, the vibration transmission sheet elastically supports the magnet assembly from one side.

9. The sound output device according to any one of claims 1 to 3, wherein the bone conduction sound generation unit includes a magnetic circuit system, a coil, a first vibration transmission sheet and a second vibration transmission sheet, the magnetic circuit system includes a magnet assembly, the coil is fitted outside the magnet assembly around an axis parallel to the vibration direction of the bone conduction sound generation unit, and in the vibration direction, the first vibration transmission sheet and the second vibration transmission sheet each elastically support the magnet assembly from opposite sides of the magnet assembly.

10. The magnetic circuit system further includes a magnetic flux conduction cover, the magnet assembly includes a magnet and a first magnetic flux conduction plate and a second magnetic flux conduction plate located on opposite sides of the magnet in the vibration direction of the bone conduction sound generating unit, the coil is fitted to the outside of the magnet assembly around an axis parallel to the vibration direction of the bone conduction sound generating unit, the first vibration transmission sheet elastically supports the magnet assembly from the side of the first magnetic flux conduction plate away from the second magnetic flux conduction plate, the second vibration transmission sheet elastically supports the magnet assembly from the side of the second magnetic flux conduction plate away from the first magnetic flux conduction plate, the magnetic flux conduction cover is fitted to the outside of the coil around the axis, the edge region of the first vibration transmission sheet is connected to one end of the magnetic flux conduction cover, and the edge region of the second vibration transmission sheet is connected to the other end of the magnetic flux conduction cover, as described in claim 9.

11. The acoustic output device according to claim 9, wherein the magnet assembly includes a first magnet and a second magnet arranged in a stack along the vibration direction, the first magnet and the second magnet having different magnetization directions, the central region of the first vibration transmission sheet is connected to the side of the first magnet away from the second magnet, and the central region of the second vibration transmission sheet is connected to the side of the second magnet away from the first magnet.

12. The acoustic output device according to claim 11, wherein the magnet assembly further includes a magnetic flux conducting plate interposed between the first magnet and the second magnet, and the coil overlaps with the side surface of the magnetic flux conducting plate when orthogonally projected onto the outer surface of the magnet assembly along a direction perpendicular to the vibration direction.

13. The sound output device according to claim 1, wherein at frequencies greater than 10 kHz, the sound pressure level of the sound output device having the bone conduction sound generation unit and the piezoelectric sound generation unit is higher than the sound pressure level of the sound output device having only the bone conduction sound generation unit.

14. The sound output device according to claim 1, wherein the piezoelectric sound generating unit is used to output bone conduction sound waves, and the angle between the vibration direction of the piezoelectric sound generating unit and the vibration direction of the bone conduction sound generating unit is in the range of -45° to 45°.

15. The sound output device according to claim 1, wherein one end of the piezoelectric element is connected to the housing of the sound output device, and the other end of the piezoelectric element is suspended within the housing space of the housing.

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