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, and more particularly to an acoustic output device.

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 human 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]

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Mode for Carrying Out the Invention

[0006] To more clearly explain the technical means of the embodiments of the present application, the drawings necessary for the description of the embodiments will be briefly described below. Obviously, the drawings described below are only part of the examples or embodiments of the present application, and those skilled in the art can apply the present application to other similar scenarios based on these drawings without creative effort. Unless otherwise clear from the context or separately explained, the same reference numerals in the drawings represent the same structure or operation.

[0007] It should be understood that the "system", "device", "unit" and / or "module" used in this specification is a way to distinguish various assemblies, elements, members, parts or assemblies at different levels. However, other expressions can be used instead of the above terms if other terms can achieve the same purpose.

[0008] As shown in the present application and the claims, unless the context clearly indicates otherwise, terms such as "one", "a", "a kind", and / or "the" do not particularly mean the singular form and may include the plural form. Generally, the terms "comprising" and "containing" merely present that they include the specifically identified steps and elements, and these steps and elements are not an exclusive listing, and the method or device may also include other steps or elements.

[0009] Embodiments of this specification describe an acoustic output device. In some embodiments, the acoustic output device may include a bone conduction voice generation unit and a piezoelectric voice generation unit. The bone conduction voice generation unit can generate bone conduction sound waves having at least one resonance peak within a frequency range of 1 kHz or less, and the piezoelectric voice generation unit can generate sound waves having at least one resonance peak within a frequency range of 6 kHz or more. Specifically, the bone conduction voice generation unit outputs intermediate frequency sound waves, and the piezoelectric voice generation unit utilizes its own characteristics (for example, the natural frequency of the piezoelectric element included in the piezoelectric voice generation unit) to output high frequency sound waves. By complementing and cooperating with each other, the acoustic output device can achieve a good voice output effect at high frequencies, and when the user wears the acoustic output device, they can receive a large listening volume in the high frequency band. In some embodiments, the piezoelectric voice generation unit and the bone conduction voice generation unit may be disposed on the side of the housing of the acoustic output device that abuts against the person's face, and generate bone conduction sound waves transmitted to the person's ear through the bone. In some embodiments, the bone conduction voice generation unit may be disposed on the side of the housing of the acoustic output device that abuts against the person's face, and generate bone conduction sound waves transmitted to the person's ear through the bone. The piezoelectric voice generation unit may be disposed at a position that does not abut against the person's face of the housing of the acoustic output device. The mechanical vibration generated by the piezoelectric voice generation unit is transmitted to the housing, and the housing generates bone conduction sound waves transmitted to the person's ear through the bone, or the housing generates air conduction sound waves transmitted to the person's ear through the air, or the mechanical vibration of the piezoelectric voice generation unit drives the surrounding air to vibrate and generates air conduction sound waves transmitted to the person's ear through the air. The acoustic output device according to the embodiments of this specification uses the piezoelectric voice generation unit to complement the high frequency voice output, thereby expanding the frequency response range of the acoustic output device and realizing a rich auditory experience in which the voice sounds clearer and more detailed.

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

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

[0012] The bone conduction sound generating unit 110 is used to convert an audio signal into a bone conduction sound wave. In some embodiments, the bone conduction sound generating unit 110 may include a vibration element (also referred to as 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 area. The vibration element generates mechanical vibrations in response to the audio signal, and the vibration transmission element vibrates in response to the vibration of the vibration element and transmits the vibration it receives (that is, the bone conduction sound wave) directly to the user's ear through the user's muscles, bones, blood, etc. In some embodiments, the acoustic output device 100 may include a housing. The vibration element is connected to the housing through an elastic element (for example, a vibration transmission sheet) or directly connected to the housing. When the user wears the acoustic output device 100, at least a part of the structure of the housing (for example, the side wall of the housing or a silicone layer covering the side wall) may be in contact with the user's face area, and the housing can transmit the vibration it receives (that is, the bone conduction sound wave) to the user's ear through the user's muscles, bones, blood, etc. It should be noted that while the bone conduction sound generating unit 110 outputs a bone conduction sound wave, its vibration also drives and vibrates the surrounding air to generate a small amount of air conduction sound wave. More descriptions regarding the bone conduction sound generating unit 110 can be referred to in other parts of this specification, for example, FIGS. 3A, 3B, 6A - 9 and their related descriptions.

[0013] The piezoelectric audio generating unit 120 is used to convert an audio signal into a bone-conducted sound wave and / or an air-conducted sound wave. In some embodiments, the piezoelectric audio generating unit 120 may include one or more piezoelectric elements, and 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 vibrations. When the piezoelectric audio generating unit 120 is used to convert an audio signal into a bone-conducted sound wave, the piezoelectric audio generating unit 120 is in direct contact with the user's face area or indirectly (e.g., via a housing, a vibration transmission element, or a silicone layer covering the side wall of the housing, the vibration transmission element, or the piezoelectric audio generating unit 120) to transmit vibrations to the user's ear through the user's muscles, bones, blood, etc., to realize the output of the bone-conducted sound wave. In some embodiments, the piezoelectric audio generating 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. Under the action of the driving voltage, the piezoelectric element vibrates to drive the vibration transmission sheet to generate mechanical vibrations. The vibration transmission sheet transmits the mechanical vibrations to the housing and transmits the mechanical vibrations to the user's face area via the housing to generate a bone-conducted sound wave. In some embodiments, the piezoelectric audio generating unit 120 may be used to convert an audio signal into an air-conducted sound wave. For example, the piezoelectric audio generating unit 120 vibrates based on the audio signal and transmits the vibrations to the housing. The vibration of the housing drives the surrounding air to vibrate to generate an air-conducted sound wave, or the piezoelectric audio generating unit 120 vibrates to drive the air around the piezoelectric audio generating unit to vibrate to generate an air-conducted sound wave. In some embodiments, the piezoelectric audio generating unit 120 may include a piezoelectric element and a diaphragm. The piezoelectric element is connected to the diaphragm. The piezoelectric element vibrates in response to the audio signal and drives the diaphragm to vibrate. The diaphragm drives the surrounding air to vibrate to generate an air-conducted sound wave.In some embodiments, the piezoelectric audio generating 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. Under the action of a driving voltage, the piezoelectric element vibrates to drive the vibration transmission sheet to generate mechanical vibrations. The vibration transmission sheet generates mechanical vibrations and at the same time drives the air in its vicinity to vibrate to generate air-conducted sound waves. Further, the vibration transmission sheet transmits the mechanical vibrations to the housing, and the housing generates mechanical vibrations to drive the air near the housing to vibrate to generate air-conducted sound waves. In some embodiments, the housing may include one or more sound conduction holes, and the air-conducted sound waves in the housing are radiated to the outside through the sound conduction holes and can be received by a person's ear. It should be noted that while the piezoelectric audio generating unit 120 outputs bone-conducted sound waves, its vibration also drives the surrounding air to vibrate to generate a small amount of air-conducted sound waves. At the same time as outputting the air-conducted sound waves, its vibration also drives the part of the acoustic output device 100 that contacts a person's face to vibrate to generate a small amount of bone-conducted sound waves. More descriptions regarding the piezoelectric audio generating unit 120 can be found in other parts of this specification, for example, FIGS. 3A to 6B and their related descriptions.

[0014] The mechanical vibration output by the above-described bone conduction sound generation unit 110, that is, the bone conduction sound wave, has at least one resonance peak within the frequency range of 1 kHz or less. That is, the bone conduction sound generation unit 110 has a good acoustic output effect near the resonance frequency corresponding to the resonance peak. In some embodiments, the bone conduction sound generation unit 110 generates a bone conduction sound wave having at least one resonance peak within the frequency range of 100 Hz to 1 kHz. Preferably, the bone conduction sound generation unit 110 generates a bone conduction sound wave having at least one resonance peak within the frequency range of 200 Hz to 900 Hz. More preferably, the bone conduction sound generation unit 110 generates a bone conduction sound wave having at least one resonance peak within the frequency range of 300 Hz to 800 Hz. The piezoelectric sound generation unit 120 has good sensitivity even at high frequencies (for example, 1000 Hz to 40000 Hz) due to the characteristics of the piezoelectric element itself (for example, the natural frequency of the piezoelectric element). The sound wave (bone conduction sound wave or air conduction sound wave) output by it becomes a sound wave having at least one resonance peak within the frequency range of 6 kHz or more (for example, within the frequency range of 6 kHz to 40 kHz). That is, the piezoelectric sound generation unit 120 has a good acoustic output effect near the resonance frequency corresponding to the resonance peak. In some embodiments, the piezoelectric sound generation unit 120 can output a sound wave having at least one resonance peak within a frequency range greater than 7 kHz. In some embodiments, the piezoelectric sound generation unit 120 can output a sound wave having at least one resonance peak within a frequency range greater than 8 kHz. In some embodiments, the piezoelectric sound generation unit 120 can output a sound wave having at least one resonance peak within a frequency range greater than 9 kHz. Specifically, in some embodiments, the piezoelectric sound generation unit 120 can output a sound wave having one resonance peak near 10 kHz.Since the audio output device 100 simultaneously has a bone conduction voice generation unit 110 and a piezoelectric voice generation unit 120, the voice frequency of the output of the audio output device 100 can cover from intermediate frequencies to high frequencies, achieving the purpose of expanding the frequency response range of the audio output device 100, and complementing the voice output at high frequencies accordingly, realizing a rich auditory experience where voices can be heard more clearly and in detail.

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

[0016] In some embodiments, the acoustic output device 100 may include at least one excitation source, and the excitation source may be used to provide an excitation voltage to the piezoelectric element and the bone conduction sound generation unit 110. The piezoelectric element and the bone conduction sound generation unit 110 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. In some embodiments, the excitation voltage provided by the excitation source may be an audio signal that has undergone a voltage transformation (e.g., step-up or step-down) process. 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 respectively provide the same excitation voltage to the piezoelectric element and the bone conduction sound generation unit 110, so that the piezoelectric element and the bone conduction sound generation unit 110 vibrate under the drive 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. Under the drive of the low excitation voltage, the bone conduction sound generation unit 110 mainly generates sound waves in low frequencies (e.g., 20 Hz to 500 Hz), medium-high frequencies (e.g., 500 Hz to 6 kHz), and high frequencies (e.g., 6 kHz to 20 kHz). Since the resonance frequency of the piezoelectric element itself is high, the piezoelectric element mainly generates high-frequency sound waves, and correspondingly, the generated low-frequency and medium-high frequency sound wave components are less, which is helpful for the cooperation between the piezoelectric sound generation unit 120 and the bone conduction sound generation unit 110. Thereby, the acoustic output device 100 can realize that the bone conduction sound generation unit 110 outputs sound waves in high frequencies, medium-high frequencies, and low frequencies, and the piezoelectric sound generation unit 120 outputs high-frequency sound waves 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 (for example, 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. A higher excitation voltage can cause the piezoelectric element to generate sound waves at a higher frequency, avoiding the situation where the piezoelectric element cannot generate sound waves at a sufficiently high frequency due to its low resonance frequency. In some embodiments, the piezoelectric audio generation unit 120 can output sound waves having at least one resonance peak within a frequency range of 7 kHz or higher when driven by a higher excitation voltage. As a mere example, when the resonance frequency of the piezoelectric audio generation unit 120 is 8 kHz, it is necessary to compensate for the output within the frequency range of 10 kHz to 14 kHz of the bone conduction audio generation unit 110 by the piezoelectric audio generation unit 120. At this time, the boost circuit can be used to boost the excitation voltage of the piezoelectric audio generation unit 120. The piezoelectric audio generation unit 120 can output sound with a high sound pressure level within the range of 10 kHz to 14 kHz when driven by the boosted excitation voltage, achieving the purpose of compensating for the output within the frequency range of 10 kHz to 14 kHz of the bone conduction audio generation unit 110 by the piezoelectric audio generation unit 120.

[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 sound generation 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 sound generation 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 sound generation unit 110 and the piezoelectric sound generation unit 120 respectively, the bone conduction sound generation unit 110 intensively generates sound waves in an intermediate frequency range, and the piezoelectric sound generation unit 120 intensively generates sound waves in a high frequency range. At the same time, the piezoelectric sound generation 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 sound generation 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 boosting circuit. The function of the second boosting circuit is similar to that of the first boosting circuit and is used to boost the signal in the second frequency range. Compared with the low-voltage signal in the second frequency range, the boosted signal in the second frequency range enables the piezoelectric sound generation 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-conduction voice generation unit 130. The air-conduction voice generation unit 130 is used to convert an audio signal into an air-conduction sound wave, and the air-conduction sound wave has at least one resonance peak within a frequency range of 500 Hz or less (for example, within a frequency range of 20 Hz to 500 Hz). That is, the air-conduction voice generation unit 130 has a strong acoustic output effect near the resonance frequency corresponding to its resonance peak, that is, the volume of the output voice is large. In some embodiments, the acoustic output device 100 may simultaneously include an air-conduction voice generation unit 130, a bone-conduction voice generation unit 110, and a piezoelectric voice generation unit 120. The air-conduction voice generation unit 130 is mainly used for low-frequency output, the bone-conduction voice generation unit 110 is mainly used for intermediate-frequency output, and the piezoelectric voice generation unit 120 is mainly used for high-frequency output. Thereby, the voice output by the acoustic output device 100 can cover from low frequencies to high frequencies, and the output intensity of the voice is improved within the entire frequency band range, effectively improving the overall sound quality.

[0021] In some embodiments, the frequency division circuit included in the acoustic output device 100 can perform frequency division on the signal in the first frequency range based on the second crossover frequency to generate a signal in the first sub-frequency range and a signal in the second sub-frequency range. The second crossover frequency is set within the intermediate frequency range (for example, 500 Hz to 1 kHz), and the second crossover frequency may be 500 Hz. A signal lower than the second crossover frequency is a signal in the first sub-frequency range, and a signal higher than the second crossover frequency is a signal in the second sub-frequency range. The signal in the first sub-frequency range is used to drive the air-conduction voice generation unit 130 to generate low-frequency sound waves, and the signal in the second sub-frequency range is used to drive the bone-conduction voice generation unit 110 to generate intermediate-frequency sound waves. More descriptions regarding the air-conduction voice generation unit 130 can be referred to other parts of this specification, for example, FIGS. 6A - 6B and their related descriptions.

[0022] Hereinafter, with reference to FIGS. 3A to 5, various embodiments in which the acoustic output device 100 includes a bone conduction sound generation unit and a piezoelectric sound generation unit will be described.

[0023] FIG. 3A is a schematic configuration diagram of an acoustic output device according to some embodiments of the present specification. As shown in FIG. 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 has a three-dimensional structure having an accommodation space (also referred to as an accommodation cavity) inside, and when the user wears the acoustic output device 300A, the side wall 341A of the housing 340A can be in direct contact with the user's face. In some embodiments, the side wall 341A may be one side wall 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 (for example, a vibration damping sheet). In some embodiments, the bone conduction sound generation unit 310A may be installed in the accommodation space of the housing 340A, and may be connected to the side wall 341A or other side walls of the housing 340A via an elastic element (for example, a vibration transmission sheet and / or a vibration damping sheet), or may be 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 directly transmitted to the user's muscles, bones, blood, etc., or may be transmitted to the user's muscles, bones, blood, etc. via the side wall 341A. In some embodiments, the piezoelectric sound generation unit 320A may include only a piezoelectric element, and the piezoelectric element may be installed on the inner surface or the outer surface of the side wall 341A, or may be embedded in the side wall 341A. The piezoelectric element may have a plate-like structure, and at least a part of the edge of the piezoelectric element is connected to the side wall 341A. For example, in some embodiments, the piezoelectric element may have a circular plate-like structure with a peripheral edge fixed to the side wall 341A. When a signal is transmitted to the piezoelectric element, a region of the piezoelectric element not fixed to the side wall 341A deforms and vibrates and is transmitted to the user. Alternatively, in some embodiments, the piezoelectric element may have an annular plate-like structure with an outer peripheral edge or an inner peripheral edge fixed to the side wall 341A. When a signal is transmitted to the piezoelectric element, a region of the piezoelectric element not fixed to the side wall 341A deforms and vibrates and is transmitted to the user.In some other embodiments, the piezoelectric audio generating unit 320A may include a piezoelectric element and a diaphragm (not shown). The piezoelectric element and the diaphragm are located inside the housing 340A. The piezoelectric element is fixed within the accommodation 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. Under the action of a driving voltage, the piezoelectric element vibrates to drive the diaphragm to generate mechanical vibrations. The diaphragm transmits the mechanical vibrations to the housing 340A, and the side wall 341A of the housing 340A transmits the mechanical vibrations to the user's face area to generate bone conduction sound waves. Note that the diaphragm may be an independent structure from the housing 340A or the side wall of the housing 340A, or may be integrally formed with the housing 340A or the side wall of the housing 340A.

[0024] In some embodiments, the housing 340A may have 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 frustum structure. In some embodiments, the internal accommodation 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 accommodation space may also be a rectangular parallelepiped. Also, for example, the outer contour of the housing 340A may be a rectangular parallelepiped, and the accommodation space may be a sphere.

[0025] Taking the housing 340A having a rectangular parallelepiped structure as an example, the side wall 341A of the housing 340A can directly contact the user's face with respect to the outer surface of the accommodation space. The bone conduction audio generating unit 310A may be connected to the side wall 341A via a vibration transmission element. The vibration transmission element vibrates in response to the vibration of the bone conduction audio generating unit 310A and transmits the vibration it receives to the side wall 341A. Further, the side wall 341A transmits the vibration to the user's face area.

[0026] In some embodiments, the piezoelectric audio generating unit 320A may be installed on the inner surface of the side wall 341A. At least a part of the structure of the piezoelectric audio generating unit 320A may be connected to the side wall 341A. For example, the piezoelectric element of the piezoelectric audio generating unit 320A may have a sheet-like structure, a concave groove may be formed on the inner surface of the side wall 341A, the piezoelectric element may be located in the concave groove, the edge of the piezoelectric element may be connected to the corresponding side wall of the concave groove, the piezoelectric element may be substantially parallel to the bottom wall of the concave groove, and the piezoelectric element and the bottom wall of the concave groove may be installed at an interval, thereby ensuring that the piezoelectric element can vibrate under the action of a driving voltage. Also, for example, the piezoelectric audio generating unit 320A may include a diaphragm and a piezoelectric element, and the piezoelectric element may be 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, and then the side wall 341A transmits the vibration to the user's face area. In some embodiments, the piezoelectric audio 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 part of the structure of the piezoelectric audio generating unit 320A may be in direct contact with the user's face area, so that the mechanical vibration of the piezoelectric audio generating unit 320A can be directly transmitted to the user's face area. Note that the inner surface of the side wall 341A is the side that contacts the accommodation space of the side wall 341A, and correspondingly, the outer surface of the side wall 341A is the side that is away from the accommodation 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 (for example, a silicone layer), thereby protecting the piezoelectric element and at the same time improving the comfort when the user wears it. In some embodiments, the connection between the piezoelectric audio generating unit 320A and the side wall 341A may be realized by the connection between a part thereof and the side wall 341A. For example, by connecting the edge or the middle part of the piezoelectric audio generating unit 320A to the side wall 341A, most of the piezoelectric audio generating unit 320A is fixed to the side wall 341A, avoiding affecting the vibration of the piezoelectric audio generating unit 320A.In some embodiments, the piezoelectric element of the piezoelectric voice generating unit 320A may have a plate-like structure, and the piezoelectric element may have a plate-like structure with a regular or arbitrary irregular shape such as a rectangle, a circle, an annular shape, an ellipse, a semi-circle, or a 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 (the portion other than the edge region) of the piezoelectric element is suspended and installed with respect to 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 (the portion other than the outer edge region) of the piezoelectric element is suspended and installed with respect to the side wall 341A, or when the size of the piezoelectric element is larger than that of the side wall 341A, the piezoelectric element may be externally fitted to the side wall 341A.

[0027] In some embodiments, when the piezoelectric voice generating unit 320A is mainly used for outputting bone conduction sound waves, the included angle between the vibration direction of the piezoelectric voice generating unit 320A and the vibration direction of the bone conduction voice generating unit 310A may be within an angular range of -45° to 45°. Thereby, the cancellation between the sound wave vibration generated by the piezoelectric voice generating unit 320A and the sound wave generated by the bone conduction voice generating unit 310A is minimized as much as possible, and the output ability and output effect of the bone conduction sound waves are improved. In some embodiments, the included angle between the vibration direction of the piezoelectric voice generating unit 320A and the vibration direction of the bone conduction voice generating unit 310A may be within an angular range of -20° to 20°. In some embodiments, the vibration direction of the piezoelectric voice generating unit 320A and the vibration direction of the bone conduction voice generating unit 310A may be substantially the same. In some embodiments, the vibration direction of the piezoelectric voice generating unit 320A and the vibration direction of the bone conduction voice generating unit 310A may be the same.

[0028] FIG. 3B is a schematic configuration diagram of an acoustic output device according to some other embodiments of the present specification. The overall structures of the acoustic output device 300B shown in FIG. 3B and the acoustic output device 300A shown in FIG. 3A are substantially the same. The main difference is that the piezoelectric voice generation unit 320B is arranged on the side facing the side wall 341B, and the vibration generated by the piezoelectric voice generation unit 320B is transmitted to the housing 340B. The housing 340B receives the vibration and vibrates the surrounding air to generate an air-conducted sound wave. As described above, in such a situation, the mechanical vibration generated by the piezoelectric voice generation unit 320B may be transmitted to the user's muscles, bones, blood, etc. through the housing 340B to generate a bone-conducted sound wave. Since the housing 340B, the bone-conducted voice generation unit 310B, and the piezoelectric voice generation unit 320B shown in FIG. 3B are similar in structure to the housing 340A, the bone-conducted voice generation unit 310A, and the piezoelectric voice generation unit 320A shown in FIG. 3A, the description thereof is omitted here.

[0029] Taking the example that the housing 340B has a cuboid structure, in some embodiments, the piezoelectric audio generating unit 320B may be installed on a side wall facing or adjacent to the side wall 341B of the housing 340B. The vibration of the piezoelectric audio generating unit 320B can be partially transmitted to the side wall 341B through the side wall facing or adjacent to the side wall 341B of the housing 340B to generate bone conduction sound waves. In some embodiments, the piezoelectric audio generating unit 320B may be installed on the inner or outer surface of the side wall facing or adjacent to the side wall 341B of the housing 340B, or may be fitted to the side wall facing or adjacent to the side wall 341B of the housing 340B. It should be noted that when the piezoelectric audio generating unit 320B is located on a side wall facing or adjacent to the side wall 341B of the housing 340B, the vibration of the piezoelectric audio generating unit 320B may also cause the vibration of the air around the piezoelectric audio generating unit 320B to generate air conduction sound waves. At the same time, the vibration of the piezoelectric audio generating unit 320B is transmitted to the housing 340B, and the housing 340B may vibrate to drive the air around the housing 340B to vibrate to generate air conduction sound waves. In particular, when the piezoelectric audio generating unit 320B is located on the side wall facing the side wall 341B of the housing 340B, when the mechanical vibration generated by the piezoelectric audio generating unit 320B is transmitted to the side wall 341B, the vibration is greatly lost. At this time, the vibration of the piezoelectric audio generating unit 320B mainly causes the vibration of the air around the piezoelectric audio generating unit 320B and the housing 340B to generate air conduction sound waves. In some embodiments, the piezoelectric audio generating unit 320B may be installed at any other position that does not contact the human face of the housing 340B. For example, the piezoelectric audio generating unit 320B may be suspended and installed in the accommodation space of the housing 340B, and the piezoelectric audio generating unit vibrates to drive the surrounding air to vibrate to generate air conduction sound waves. In some embodiments, the housing 340B may be provided with a sound conduction hole (not shown in FIG. 3B) for radiating the air conduction sound waves generated by the piezoelectric audio generating unit 320B in the accommodation space to the outside so that they can be received by the human ear.In some embodiments, the piezoelectric audio generating unit 320B may include a piezoelectric element, a vibration transmission element, and a diaphragm. One end of the piezoelectric element is connected to the housing 340B of the audio output device, and the other end is suspended and installed within the accommodation space of the housing 340B. A diaphragm is installed on the side of the housing 340B facing the human body. The vibration transmission element is installed within the accommodation space of the housing 340B. One end of the vibration transmission element is connected to the piezoelectric element, and the other end contacts the diaphragm. The piezoelectric element drives the diaphragm to vibrate through the vibration transmission element, and the diaphragm drives the surrounding air to vibrate to generate air-conducted sound waves that can be received by a person's ear. In some embodiments, the diaphragm may be installed on a sidewall adjacent to or facing the sidewall 341B of the housing 340B. At this time, the diaphragm may be regarded as a part of the sidewall, or the diaphragm may be located within the accommodation space of the housing 340B. At this time, the housing 340B may be provided with a sound conduction hole for radiating the air-conducted sound waves generated by the piezoelectric audio generating unit 320B within the accommodation space to the outside so that they can be received by a person's ear. Hereinafter, with reference to FIGS. 4 and 5, various embodiments in which the piezoelectric audio generating unit 320B is mainly configured to generate air-conducted sound waves will be described.

[0030] FIG. 4 is an exemplary structural diagram of a piezoelectric audio generating unit according to some embodiments of the present specification. As shown in FIG. 4, the piezoelectric audio generating unit 420 includes a piezoelectric element 421. One end of the piezoelectric element 421 is connected to the housing 440 of the audio output device, and the other end is suspended and installed within the accommodation space of the housing 440. A sound conduction hole 442 is installed on the side of the housing 440 facing the human body. The piezoelectric element 421 vibrates to drive the surrounding air to vibrate to generate air-conducted sound waves and radiate them to the outside through the sound conduction hole 442. Since the housing 440 shown in FIG. 4 is similar to the housing 340A shown in FIG. 3A, the description is omitted here.

[0031] In some embodiments, both ends of the piezoelectric element 421 are a fixed end and a free end, respectively. The fixed end is an end in the piezoelectric element 421 that provides a fixing or supporting action to other parts. In some embodiments, during the vibration process of the piezoelectric element 421, the vibration intensity of the fixed end is small compared to other parts (e.g., the free end) of the piezoelectric element 421. As a mere example, the fixed end may be a position in the piezoelectric element 421 where the vibration acceleration or acceleration level is smaller than the vibration acceleration threshold or acceleration level threshold. In some embodiments, the fixed end may be connected to a fixed position or structure on the acoustic output device. The fixed position or structure here may be a position or structure in the acoustic output device where the vibration acceleration or acceleration level is smaller than the vibration acceleration threshold or acceleration level threshold. The fixed end shown in FIG. 4 is connected to the housing 440. The free end is the end where the piezoelectric element 421 generates sound, is away from the fixed end, and can vibrate more freely relative to the fixed end. The free end shown in FIG. 4 is the suspended end in the piezoelectric element 421. In some embodiments, the piezoelectric element 421 may have a plate-like, strip-like structure or any other structure where the length is greater than the width and thickness. For example, the piezoelectric element 421 may have a prismatic structure. The length is the dimension in its length direction (direction a shown in FIG. 4), the thickness is the dimension in its thickness direction (direction b shown in FIG. 4), and the width is the dimension in its width direction (perpendicular to both the length direction and the thickness direction at the same time).

[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 includes, but is not limited to, metals, alloys, resins, glass fibers, carbon fibers, etc., or any combination thereof. In some embodiments, the piezoelectric layer 4211 and the base layer 4212 are stacked 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 pasting. In some embodiments, the piezoelectric element 421 may include two layers of the piezoelectric layer 4211 and the base layer 4212, and the two layers of the piezoelectric layer 4211 and the base layer 4212 are stacked in the thickness direction of the piezoelectric element 421. In some embodiments, the piezoelectric element 421 may include a plurality of piezoelectric layers 4211, and the plurality of piezoelectric layers 4211 and the base layer 4212 are stacked.

[0033] In some embodiments, the sound conduction hole 442 may be installed at any other position that does not contact the human face of the housing 440. For example, the sound conduction hole 442 may be installed on the side surface adjacent to the side surface of the housing 440 that contacts the human face. In some embodiments, the sound conduction hole 442 communicates the accommodation cavity of the housing 440 with the outside of the housing 440. In some embodiments, the sound conduction hole 442 is installed through the side wall of the housing 440. In some embodiments, the sound conduction hole 442 may have a regular or arbitrary irregular shape such as a rectangle, a circle, an annular shape, an ellipse, a semi-circle, a polygon, a triangle, etc.

[0034] In some embodiments, the piezoelectric sound generating unit 420 may include a plurality of different piezoelectric elements, and the plurality of piezoelectric elements may each have a different resonance frequency. The piezoelectric elements having different resonance frequencies can output airborne sound waves in different frequency bands, thereby compensating for sound wave outputs in different frequency bands. For example, the piezoelectric sound generating unit 420 includes a third piezoelectric element and a fourth piezoelectric element. The resonance frequency of the third piezoelectric element is 7 kHz and it can output airborne sound waves in the range of 4 kHz to 9 kHz. The resonance frequency of the fourth piezoelectric element is 11 kHz and it can output airborne sound waves in the range of 9 kHz to 12 kHz. The combination of the third piezoelectric element and the fourth piezoelectric element can compensate for sound wave outputs within the frequency range of 4 kHz to 12 kHz.

[0035] FIG. 5 is an exemplary structural diagram of a piezoelectric audio generating unit according to some embodiments of the present specification. As shown in FIG. 5, the piezoelectric audio generating unit 520 includes a piezoelectric element 521, a vibration transmission element 522, and a diaphragm 550. One end of the piezoelectric element 521 is connected to the housing 540 of the acoustic output device, and the other end is suspended and installed within the accommodation space of the housing 540. A diaphragm 550 is installed on the side of the housing 540 facing the human body. The vibration transmission element 522 is installed within the accommodation 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 diaphragm 550. The piezoelectric element 521 drives the diaphragm 550 to vibrate through the vibration transmission element 522. The diaphragm 550 drives the surrounding air to vibrate, generating an air-conducted sound wave that can be received by a human ear. In some embodiments, the diaphragm 550 may be installed on the side wall of the housing 540. For example, it may be installed on the side wall adjacent to or facing the side wall 341B shown in FIG. 3B. At this time, the diaphragm 550 may be regarded as a part of the side wall, and the air-conducted sound wave generated by the vibration of the diaphragm 550 can be directly transmitted to the outside. In some embodiments, the diaphragm 550 may be located within the accommodation space of the housing 540. At this time, the housing 540 may be provided with a sound conduction hole for radiating the air-conducted sound wave generated by the piezoelectric audio generating unit 520 within the accommodation space to the outside so that it can be received by a human ear. Since the housing 540 and the piezoelectric element 521 shown in FIG. 5 are similar to the housing 440 and the piezoelectric element 421 shown in FIG. 4, the description is omitted here.

[0036] In some embodiments, the peripheral side of the diaphragm 550 is connected to the housing 540. In some embodiments, the diaphragm 550 may be installed at any other position that does not abut against the human face of the housing 540. For example, the diaphragm 550 may be installed on a side surface of the housing 540 that is substantially perpendicular to the human face.

[0037] In some embodiments, the diaphragm 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. When the piezoelectric element 521 receives an electric field perpendicular to its surface, the piezoelectric element 521 receives a stress along the length direction of the piezoelectric element 521. At this time, the piezoelectric layer of the piezoelectric element 521 deforms to drive the overall structure of the piezoelectric element 521 to deform, generating vibrations 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 by the vibration transmission element 522, and the diaphragm 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 shape, a plate shape, a strip shape structure, or a spiral shape structure. In some embodiments, the piezoelectric audio generating unit 520 may not include the vibration transmission element 522. One end of the piezoelectric element 521 is connected to the housing 540 of the acoustic output device, and the other end directly contacts the diaphragm 550. The piezoelectric element 521 directly drives the diaphragm 550 to vibrate, generating air-conducted sound waves.

[0038] In some embodiments, in order to avoid the vibrations of the diaphragm 550 of the piezoelectric audio generating unit and the vibrations of the bone-conducted audio generating unit affecting each other through the vibration transmission of the housing 540, the vibration direction of the diaphragm 550 and the vibration direction of the bone-conducted audio generating unit can be made perpendicular to each other. Here, perpendicular can be understood as substantially perpendicular. In some embodiments, the included angle between the vibration direction of the diaphragm 550 and the vibration direction of the bone-conducted audio generating unit may be within the angular range of 70° to 110°.

[0039] Hereinafter, with reference to FIGS. 6A and 6B, various embodiments in which the acoustic output device includes a bone-conducted audio generating unit, a piezoelectric audio generating unit, and an air-conducted audio generating unit will be described.

[0040] FIG. 6A is an exemplary structural diagram of an acoustic output device according to some embodiments of the present specification. FIG. 6B is an exemplary structural diagram of an acoustic output device according to some further embodiments of the present specification. As shown in FIGS. 6A and 6B, the acoustic output device 600 includes a housing 640, a bone conduction voice generation unit 610, a piezoelectric voice generation unit 620, and an air conduction voice generation unit 630. The air conduction voice generation unit 630 is used to output low-frequency air conduction sound waves. The bone conduction voice generation unit 610 is used to output intermediate-frequency bone conduction sound waves. The piezoelectric voice generation unit 620 is used to output high-frequency air conduction sound waves. The accommodation cavity of the housing 640 is partitioned into two independent cavities. The bone conduction voice generation unit 610 is installed alone in one cavity. The piezoelectric voice generation unit 620 and the air conduction voice generation unit 630 are arranged in parallel (as shown in FIG. 6A) or stacked (as shown in FIG. 6B) in another cavity. Thereby, it is possible to avoid the vibration of the bone conduction voice generation unit 610 being transmitted by the air in the housing 640 and affecting the air conduction sound waves of the piezoelectric voice generation unit 620 and the air conduction voice generation unit 630. More descriptions regarding the air conduction voice generation unit 630 can be referred to FIG. 1. More descriptions regarding the bone conduction voice generation unit 610 and the housing 640 can be referred to FIGS. 1, 3A, and 3B. More descriptions regarding the piezoelectric voice generation unit 620 can be referred to FIGS. 1 and 3B to 5.

[0041] In some embodiments, the air-conduction voice generating unit 630 may include a diaphragm. The diaphragm vibrates based on an audio signal. The diaphragm drives the air inside the housing 640 of the acoustic output device 600 to vibrate, generating air-conduction sound waves. The air-conduction sound waves inside the housing 640 are radiated to the outside through the sound conduction holes and can be received by a human ear. In some embodiments, the air-conduction voice generating unit 630 may further include a diaphragm, a voice coil, and a magnetic circuit structure. The diaphragm and the magnetic circuit structure are connected through the voice coil. The internal magnetic field of the magnetic circuit structure changes in response to the audio signal. The voice coil vibrates under the action of the magnetic circuit structure, and the diaphragm vibrates in response to the vibration of the voice coil. It should be noted that the diaphragm of the air-conduction voice generating unit 630 and the diaphragm of the piezoelectric voice generating unit 620 in some embodiments are not the same diaphragm, but are diaphragms respectively provided to realize the transmission of air-conduction sound waves.

[0042] In some embodiments, in order to reduce the mutual influence between the vibration of the bone-conduction voice generating unit 610 and the vibration of the air-conduction voice generating unit due to the vibration transmission of the housing 640, the included angle between the vibration direction of the diaphragm and the vibration direction of the bone-conduction voice generating 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 voice generating unit 610 may be substantially perpendicular. In some embodiments, the vibration direction of the diaphragm and the vibration direction of the bone-conduction voice generating unit 610 may be made perpendicular. In some embodiments, the piezoelectric voice generating unit 620 vibrates to generate air-conduction sound waves, and the vibration direction of the piezoelectric voice generating unit 620 and the vibration direction of the air-conduction voice generating unit may be made to coincide. Thereby, the sound wave vibration generated by the piezoelectric voice generating unit 620 and the sound wave generated by the air-conduction voice generating unit are not offset as much as possible, so as to improve the output ability and output effect of the air-conduction sound waves. In some embodiments, the vibration direction of the piezoelectric voice generating unit 620 and the vibration direction of the air-conduction voice generating unit 630 may be substantially coincident. In some embodiments, the included angle between the vibration direction of the piezoelectric voice generating unit 620 and the vibration direction of the air-conduction voice generating unit 630 may be within an angular range of -20° to 20°.

[0043] In some embodiments, the piezoelectric audio generating unit 620 and the air-conduction audio generating unit 630 may be arranged in any other form. For example, the piezoelectric audio generating unit 620 and the air-conduction audio generating unit 630 may be arranged obliquely.

[0044] In some embodiments, the acoustic output device 600 includes a housing 640, a bone-conduction audio generating unit 610, a piezoelectric audio generating unit 620, and an air-conduction audio generating unit 630. The air-conduction audio generating unit 630 is mainly used to output low-frequency air-conduction sound waves. The bone-conduction audio generating unit 610 is mainly used to output intermediate-frequency bone-conduction sound waves. The piezoelectric audio generating unit 620 is mainly used to output high-frequency bone-conduction sound waves. The accommodation cavity of the housing 640 is partitioned into two independent cavities. The bone-conduction audio generating unit 610 and the piezoelectric audio generating unit 620 are installed in one cavity, and the air-conduction audio generating unit 630 is arranged in the other cavity. Thereby, it is possible to avoid the vibration of the piezoelectric audio generating unit 620 and the bone-conduction audio generating unit 610 being transmitted by the air in the housing 640 and affecting the air-conduction sound waves of the air-conduction audio generating unit 630. More descriptions regarding the air-conduction audio generating unit 630 can be referred to FIGS. 1, 6A and 6B. More descriptions regarding the piezoelectric audio generating unit 620, the bone-conduction audio generating unit 610 and the housing 640 can be referred to FIGS. 1, 3A and 3B.

[0045] In some embodiments, in order to avoid the vibrations of the bone conduction voice generating unit 610 and the vibrations of the air conduction voice generating unit from affecting each other through the vibration transmission of the housing 640, the vibration direction of the diaphragm may be perpendicular to the vibration direction of the bone conduction voice generating unit 610. In some embodiments, the piezoelectric voice generating unit 620 may vibrate to generate bone conduction sound waves, and the vibration direction of the piezoelectric voice generating unit 620 may be made to coincide with the vibration direction of the bone conduction voice generating unit 610, so that the sound wave vibrations generated by the piezoelectric voice generating unit 620 and the sound waves generated by the bone conduction voice generating unit 610 are not offset as much as possible, thereby improving the output ability and output effect of the bone conduction sound waves.

[0046] Hereinafter, various embodiments of the bone conduction voice generating unit will be described with reference to FIGS. 7A to 8A.

[0047] Figures 7A and 7B are schematic configuration diagrams of an acoustic output device according to some embodiments of the present specification. As shown in FIGS. 7A and 7B, the acoustic output device 700 includes a housing 740, an air conduction voice generation unit 730, and a bone conduction voice generation unit 710. The housing 740 is similar to the housing 340A shown in FIG. 3A. The air conduction voice generation unit 730 is installed on the side wall of the housing 740, and the bone conduction voice generation unit 710 is installed in the accommodation cavity, and the vibration direction of the air conduction voice generation unit 730 and the vibration direction of the bone conduction voice generation unit 710 are substantially perpendicular. The so-called substantially perpendicular here means that the angle between the vibration direction of the air conduction voice generation unit 730 and the vibration direction of the bone conduction voice generation unit 710 may be within a specific angle range. In some embodiments, the specific angle range may be 70° to 110°. Preferably, the specific angle range may be 80° to 100°. In some embodiments, the diaphragm of the air conduction voice generation unit 730 may be located on the side wall adjacent to or facing the side of the housing 740 that abuts the human face. For example, holes are formed in the housing 740, and the edge of the diaphragm is connected to the corresponding hole wall of the hole. At this time, the diaphragm of the air conduction voice generation unit 730 may be regarded as a part of the side wall of the housing 740. At this time, the air conduction sound wave output by the air conduction voice generation unit 730 can be directly transmitted to the outside. Also, for example, the diaphragm of the air conduction voice generation unit 730 may be located in the accommodation cavity of the housing 740. Correspondingly, one or more sound conduction holes (not shown) may be installed in the housing 740, and the sound conduction holes may be used to transmit the air conduction sound wave generated by the air conduction voice generation unit 730 to the outside.In some embodiments, the bone conduction voice generating 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 externally fitted outside the magnet assembly 7111 around an axis parallel to the vibration direction (direction c shown in FIG. 7A) of the bone conduction voice generating unit 710. The magnetic flux conduction cover 7112 is peripherally provided outside the coil 712 along the vibration direction of the bone conduction voice generating unit 710. The magnetic flux conduction cover 7112, the coil 712, and the magnet assembly 7111 are arranged at intervals 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. In the vibration direction, the vibration transmission sheet 713A elastically supports the magnet assembly 7111 from one side of the magnet assembly 7111. Note that the air conduction voice generating unit 730 may be replaced with a piezoelectric voice generating unit. At this time, the position and structure of the piezoelectric voice generating unit in the acoustic output device 700 are similar to those of the piezoelectric voice generating unit 320A shown in FIG. 3A. Alternatively, the acoustic output device 700 may further include a piezoelectric voice generating unit. At this time, the piezoelectric voice generating unit may be located on the side wall (the side contacting the human face) of the housing 740 that contacts the human face, or on the side wall adjacent to or opposite the side of the housing 740 that contacts the human face, or inside the accommodation cavity of the housing 740. Regarding the position and structure of the piezoelectric voice generating unit in the acoustic output device 700, reference may be made to the piezoelectric voice generating units shown in FIGS. 3B, 4, and 5.

[0048] In some embodiments, the side surface connected to the bone conduction audio generating unit 710 of the housing 740 may contact the user's face area, and the vibration generated by the bone conduction audio generating 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 the vibration transmission sheet 713A, thereby suspending the magnet assembly 7111 within the accommodation cavity of the housing 740. For example, the vibration transmission sheet 713A and the magnet assembly 7111 are arranged along the vibration direction, and the side surface of the vibration transmission sheet 713A perpendicular to the vibration direction is connected to the end portion of the magnetic flux conduction cover 7112 perpendicular to the vibration direction, thereby realizing the fixation of the magnet assembly 7111. In some embodiments, the magnetic flux conduction cover 7112 may be connected to the magnet assembly 7111, thereby realizing the fixation of the magnetic flux conduction cover 7112 to the magnet assembly 7111. In some embodiments, the vibration transmission sheet 713A and the magnetic flux conduction cover 7112 are arranged along the vibration direction, and the side surface of the vibration transmission sheet 713A perpendicular to the vibration direction is connected to the end portion of the magnetic flux conduction cover 7112 perpendicular to the vibration direction. In some embodiments, the acoustic output device 700 may further include a vibration transmission sheet 713B. The side surface of the vibration transmission sheet 713B perpendicular to the vibration direction is connected to the end portion of the magnet assembly 7111 perpendicular to the vibration direction, and another side surface of the vibration transmission sheet 713B perpendicular to the vibration direction is connected to the side wall of the housing 740 perpendicular to the vibration direction. It should be noted that the acoustic output device 700 may include only the vibration transmission sheet 713A or the vibration transmission sheet 713B, or may include the vibration transmission sheet 713A and the vibration transmission sheet 713B at the same time, thereby enhancing the stability of the magnet assembly 7111 during vibration. In some embodiments, the vibration transmission sheet may be further located between the magnetic flux conduction cover 7112 and the housing 740. As shown in FIG. 7B, the vibration transmission sheet 713C has an annular structure. The inner ring side of the vibration transmission sheet 713C is connected to the circumferential side of the magnetic flux conduction cover 7112, and the outer peripheral side of the vibration transmission sheet 713C is connected to the housing 740, thereby realizing the fixation of the magnet assembly 7111 to the magnetic flux conduction cover 7112.

[0049] In some embodiments, the magnetic flux conducting cover 7112 has a housing structure with an open opening at one end. The magnet assembly 7111 is located inside the magnetic flux conducting cover 7112. One end of the magnet assembly 7111 is connected to the bottom wall facing the opening of the magnetic flux conducting cover 7112, and the side wall of the magnet assembly 7111 and the side wall of the housing 740 are installed at an interval. In some embodiments, along the direction perpendicular to the vibration direction of the bone conduction sound generating unit 710, there is an interval between the inner wall of the magnetic flux conducting cover 7112 and the side wall of the magnet assembly 7111. A magnetic gap is formed on the peripheral side of the magnetic flux conducting cover 7112 and the magnet assembly 7111. One end of the coil 712 is connected to the side of the housing 740 that abuts against the human face, the other end is inserted into the magnetic gap, and there is an interval between the other end of the coil 712 and the magnetic flux conducting cover 7112 along the vibration direction, thereby ensuring that relative movement can be realized between the magnetic circuit system 711 and the coil 712.

[0050] FIG. 8A is a schematic configuration diagram of an acoustic output device according to some embodiments of the present specification. As shown in FIG. 8A, the acoustic output device 800 includes a housing 840, an air conduction voice generation unit 830, and a bone conduction voice generation unit 810. Since the air conduction voice generation unit 830 is similar to the air conduction voice generation unit 730 shown in FIG. 7A, the description thereof is omitted here. An accommodation cavity for accommodating the bone conduction voice generation unit 810 may be formed in the housing 840. The bone conduction voice 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 externally fitted outside the magnet assembly 8111 around an axis parallel to the vibration direction of the bone conduction voice generation unit 810 (see FIG. 8A). The magnetic flux conduction cover 8112 is externally fitted to the coil 812 along the vibration direction of the bone conduction voice generation unit 810. The magnetic flux conduction cover 8112 and the magnet assembly 8111 are installed at intervals in a direction perpendicular to the vibration direction. A magnetic gap is formed between the inner wall of the magnetic flux conduction cover 8112 and the outside of the magnet assembly 8111. In the vibration direction, 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 of the present specification, opposite sides of the magnet assembly 8111 in the vibration direction of the bone conduction voice generation unit 810 are elastically supported, thereby avoiding as much as possible the mutual attraction or repulsion and shaking between the magnet assembly 8111 and the magnetic flux conduction cover 8112 due to magnetic force, which helps to improve the stability of the vibration of the bone conduction voice generation unit 810.Note that the air-conduction voice generation unit 830 may be replaced by a piezoelectric voice generation unit (for example, the piezoelectric voice generation unit 420 shown in FIG. 4 or the piezoelectric voice generation unit 520 shown in FIG. 5). The piezoelectric voice generation unit may include a piezoelectric element and a diaphragm connected to the piezoelectric element. The piezoelectric element can drive the diaphragm to vibrate to generate air-conduction sound waves. By adjusting the parameters of the piezoelectric element itself (such as structure, length, width, thickness, material, etc.), the piezoelectric voice generation unit can output mainly air-conduction sound waves in the low-frequency band so as to be similar to the air-conduction voice generation unit 830. The position and structure of the piezoelectric voice generation unit in the acoustic output device 800 are similar to those of the piezoelectric voice generation unit 320A shown in FIG. 3A. In the embodiment shown in FIG. 8A, the acoustic output device 800 further includes a piezoelectric voice generation unit 880. The piezoelectric voice generation unit 880 is located on the vibration panel 860. The piezoelectric element of the piezoelectric voice generation unit 880 vibrates under the action of a driving voltage, and this vibration is transmitted to a person's face together with the vibration of the vibration panel 860, and can let the user hear bone-conduction sound waves in a bone-conduction manner. By adjusting the parameters of the piezoelectric element itself (such as structure, length, width, thickness, material, etc.), the piezoelectric voice generation unit can output mainly bone-conduction sound waves in the high-frequency band. In some embodiments, the piezoelectric voice generation unit 880 may be located on the side wall adjacent to or facing the vibration panel of the housing 840, or may be located in the accommodation cavity of the housing 840. Regarding the position and structure of the piezoelectric voice generation unit 880 in the acoustic output device 800, reference may be made to the piezoelectric voice generation units shown in FIGS. 3B, 4, and 5. The air-conduction voice generation unit 830 is mainly used for low-frequency (for example, 20 Hz to 500 Hz) output, the bone-conduction voice generation unit 810 is mainly used for intermediate-frequency (for example, 500 Hz to 6 kHz) output, and the piezoelectric voice generation unit 880 is mainly used for high-frequency (for example, 6 kHz to 20 kHz) output. Thereby, the voice output by the acoustic output device 800 can cover from low frequency to high frequency, and the output intensity of the voice within the entire frequency band range is improved, effectively improving the overall sound quality.

[0051] In some embodiments, the acoustic output device 800 may include a vibration panel 860, and the vibration panel 860 may be connected to the bone conduction voice generation unit 810. The bone conduction voice generation unit 810 transmits the mechanical vibration generated to the human face and acts on the user's auditory nerve through the user's skin, bone, and / or tissue to form bone conduction sound waves. Note that the housing 840 may be a columnar structure (e.g., a rectangular parallelepiped structure, a cylindrical structure), a spherical shape, a trapezoidal shape, etc., or any irregular shape and combinations 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 voice generating unit 810 may be suspended in the housing cavity of the housing 840 via the vibration damping sheet 870. The vibration panel 860 may not contact the housing 840. At this time, due to the presence of the vibration damping sheet 870, the mechanical vibrations generated by the bone conduction voice generating unit 810 are less likely to be transmitted to the housing 840, and thus may not be transmitted at all. Thereby, to some extent, the housing 840 is prevented from driving the external air of the acoustic output device 800 to vibrate, which helps to reduce the sound leakage of the acoustic output device 800. Also, since the vibration panel 860 and the elements rigidly connected to the vibration panel 860, and the housing 840 and the elements rigidly connected to the housing 840 are elastically connected by the vibration damping sheet 870, it can be regarded as a substantially resonant system. At this time, by installing an additional element (for example, an element such as an air conduction voice generating unit, a piezoelectric voice generating element, a circuit element, a microphone, etc.) added to the bone conduction voice generating unit 810 on the housing 840, in a specific frequency band (for example, a resonance frequency higher than the resonance system), the vibration transmission between the additional element and the vibration panel 860 may be suppressed. That is, the influence of the additional element on the vibration of the vibration panel 860 may be reduced. Thereby, it can be guaranteed that the sensitivity of the bone conduction voice generating unit 810 in the acoustic output device 800 is not affected or less affected by the additional element in a specific frequency band, and it can be guaranteed that the acoustic output device 800 has a good acoustic output effect in a wide frequency range, and the user's auditory experience can be improved.

[0053] In some embodiments, the housing 840 may have an open end, and the vibration panel 860 may be installed outside the housing 840 and face the open end. That is, the edge of the vibration panel 860 is not connected to the open end of the housing 840. A connection rod 861 is installed between the vibration panel 860 and the bone conduction audio generating unit 810. One end of the connection rod 861 is connected to the bone conduction audio generating unit 810, and the other end passes through the open end of the housing 840 and is connected to the vibration panel 860, so that the vibrating vibration panel 860 and the bone conduction audio generating unit 810 do not contact the housing 840, thereby reducing sound leakage of the acoustic output device 800. In some embodiments, the vibration damping sheet 870 may be connected between the connection rod 861 and the housing 840 to realize suspension of the vibration panel 860 and the bone conduction audio generating unit 810.

[0054] In some embodiments, the bone conduction audio generating 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 FIG. 8A, the bracket 8140 may be connected to the end of the connection 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 accommodation cavity of the housing 840. In some embodiments, the vibration damping sheet 870 may connect the bracket 8140 and the housing 840 so as to suspend the bone conduction audio generating unit 810 within the accommodation 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 close 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, in order to simplify the assembly process, the first coil 8121 and the second coil 8122 may be inserted into the magnetic gap of the magnetic circuit system together from the side close to the vibration panel 860. In some embodiments, the bone conduction sound generation unit 810 may further include a holding part for holding the shapes of the first coil 8121 and the second coil 8122. For example, the first coil 8121 and the second coil 8122 may have an integrated structure. Specifically, the first coil 8121 and the second coil 8122 are wound around a shape-retaining material, and a holding part (for example, a holding material such as a high-temperature tape) is used to adhere to the outside of the first coil 8121 and the second coil 8122, so that the first coil 8121 and the second coil 8122 can be formed into an integrated structure. Since the first coil 8121 and the second coil 8122 fixed to the holding part extend into the magnetic gap of the magnetic circuit system from the same side of the vibration panel 860, the coil assembly process is simplified. In some embodiments, the two coils are formed by winding the same wire, or a part of the two coils is connected, so that the incoming and outgoing lines of the two coils are only two lead wires, which can facilitate wiring and the electrical connection with other subsequent structures.

[0056] In some embodiments, in the vibration direction, the edge regions 8131 on both opposite sides of the first vibration transmission sheet 813 are respectively connected to the side close to the magnetic circuit system of the bracket 8140 and the side close to the bracket 8140 of the magnetic flux conduction cover 8112. The edge region 8141 of the second vibration transmission sheet 814 is connected to the side away from the bracket 8140 of the magnetic flux conduction cover 8112. In some embodiments, the magnetic flux conduction cover 8112 may have a cylindrical structure with both ends open. In some embodiments, the magnetic flux conduction cover 8112 may have a sealed structure so that the sound generated in the magnetic circuit system does not leak 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 are respectively located on opposite sides of the magnet 81111 in the vibration direction of the bone conduction sound generating 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 magnetic flux conduction plate 81112 away from the second magnetic flux conduction plate 81113, and the central region 8142 of the second vibration transmission sheet 814 is connected to the side of the second magnetic flux conduction plate 81113 away from the first magnetic flux conduction plate 81112. In some embodiments, the corners of the first magnetic flux conduction plate 81112 and / or the second magnetic flux conduction plate 81113 away from the magnet 81111 may be chamfered. For example, by chamfering the corners on opposite sides of the first magnetic flux conduction plate 81112 and the second magnetic 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 generating unit 810, the half-height position of the first coil 8121 and the half-thickness position of the side parallel to the vibration direction of the first magnetic flux conduction plate 81112 may be at the same height, and the half-height position of the second coil 8122 and the half-thickness position 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 intensively distributed in the rectangular portion of the first magnetic flux conduction plate 81112 and / or the second magnetic flux conduction plate 81113 other than the chamfered portion.

[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 voice generating unit 810 in the accommodation cavity of the housing 840. At this time, both sides perpendicular to the vibration direction of the edge region 8131 of the first vibration transmission sheet 813 may be respectively connected to the bracket 8140 and the magnetic flux conduction cover 8112, the side perpendicular to the vibration direction of the edge region 8141 of the second vibration transmission sheet 814 may be connected to the magnetic flux conduction cover 8112, the vibration panel 860 may be connected to the bracket 8140, and there is a certain gap between the vibration panel 860 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 realizing the isolation between the housing 840 and the outside, preventing water, dust and other impurities, and at the same time 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 FIG. 8B, the magnet assembly 8111 may include a first magnet 8111a and a second magnet 8111b stacked and installed along the vibration direction, the magnetization directions of the first magnet 8111a and the second magnet 8111b are different, the first vibration transmission sheet 813 (shown in FIG. 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 FIG. 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 FIG. 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 FIG. 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 magnetic flux conduction plate 8111c interposed between the first magnet and the second magnet. In some embodiments, the number of coils 812 may be one or three. When the number of coils 812 is one, the coil (for example, the first coil 812a) overlaps the side peripheral surface of the magnetic flux conduction plate 8111c when orthogonally projected onto the outer peripheral surface of the magnet assembly 8111 along a direction perpendicular to the vibration direction. When the number of coils is three, for example, the coils may include a first coil 812a, a second coil 812b, and a third coil 812c, the first coil 812a, the second coil 812b, and the third coil 812c are distributed at intervals along the vibration direction, the first coil 812a overlaps the side peripheral surface of the magnetic flux conduction plate 8111c when orthogonally projected onto the outer peripheral surface of the magnet assembly 8111 along a direction perpendicular to the vibration direction, the second coil 812b overlaps the side peripheral surface of the first magnet 8111a when orthogonally projected onto the outer peripheral surface of the magnet assembly 8111 along a direction perpendicular to the vibration direction, and the third coil 812c overlaps the side peripheral surface of the second magnet 8111b when orthogonally projected onto the outer peripheral surface of the magnet assembly 8111 along a direction perpendicular to the vibration direction.In some embodiments, the magnetization directions of the first magnet 8111a and the second magnet 8111b are opposite to each other and both are perpendicular to the surface facing the first magnet 8111a or the second magnet 8111b of the magnetic flux conduction plate 8111c.

[0060] FIG. 9 is a schematic configuration diagram of an acoustic output device according to some embodiments of the present specification. As shown in FIG. 9, the acoustic output device 900 may include a housing 911, a vibration panel 913, and a bone conduction voice generation unit 930. In some embodiments, the housing 911 has an oral end and a hollow interior structure, and the vibration 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 voice generation unit 930. In some embodiments, the bone conduction voice 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 includes a magnet assembly 931 and a magnetic flux conduction cover 932. The coil 940 is externally fitted outside the magnet assembly 931 around an axis parallel to the vibration direction of the bone conduction voice generation unit 930 (see FIG. 9). The magnetic flux conduction cover 932 is externally fitted to the coil 940 along the vibration direction of the bone conduction voice generation unit 930. The magnetic flux conduction cover 932 and the magnet assembly 931 are installed at intervals in a direction perpendicular to the vibration direction. A magnetic gap is formed between the inner wall of the magnetic flux conduction cover 932 and the outside of the magnet assembly 931. 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 of the present specification, opposite sides of the magnet assembly 931 in the vibration direction of the bone conduction voice generation unit 930 are elastically supported, and there is no abnormal vibration such as obvious shaking, which helps to improve the vibration stability of the bone conduction voice 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 are located in the magnetic gap of the magnetic circuit system and are arranged at intervals in the vibration direction. For the specific structures and positions of the first coil 941 and the second coil 942, reference can be made to FIG. 8A and its corresponding content, and the description is omitted here.

[0061] In some embodiments, the magnetic flux conduction cover 932 is rigidly connected to the housing 911 or the vibration panel 913, and the circumferential side wall of the magnetic flux conduction cover 932 away from the magnet assembly 931 fits against 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 magnetic flux conduction cover 932 may achieve a rigid connection with the housing 911 or the vibration panel 913 by other fixing structures. In some embodiments, an edge region of any one 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 fastening and adhesion, and the vibration panel 913 is connected to the open end of the housing 911 to form a sealed cavity. In some embodiments, a side surface of any one of the first vibration transmission sheet 925 and the second vibration transmission sheet 926 close 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 formed. 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 adhesion. 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 are 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 away from the second magnetic flux conduction plate 935 of the first magnetic flux conduction plate 934, and the second vibration transmission sheet 926 can support the magnet assembly 931 from the side away from the first magnetic flux conduction plate 934 of the second magnetic flux conduction plate 935.Regarding the detailed content of 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, reference can be made 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 FIG. 8A in this specification, and the description thereof will be omitted here.

[0062] In some embodiments, the acoustic output device 900 may further include a piezoelectric voice generation unit 920, and the piezoelectric voice generation unit 920 may be located on the vibration panel 913. For example, the piezoelectric voice generation unit 920 may be located on the side of the vibration panel 913 that contacts a person's face. Also, for example, the piezoelectric voice generation unit 920 may be located on the side of the vibration panel 913 that is away from the side that abuts a person's face. Further, for example, the piezoelectric voice generation unit 920 may be fitted within the vibration panel 913. In some embodiments, the piezoelectric voice generation unit 920 may further be located on the side wall of the housing 911. For example, the piezoelectric voice generation unit 920 may be located on the side wall of the housing 911 that faces the vibration panel 913 and the adjacent side wall. In some embodiments, the acoustic output device 900 may include an air-conduction voice generation unit 910, and the air-conduction voice generation unit 910 may be located on the side away from the accommodation cavity of the corresponding side wall in the housing 911. At this time, the air-conduction sound waves emitted by the air-conduction voice generation unit 910 may be directly transmitted to the outside. In some embodiments, the air-conduction voice generation unit 910 may further be located inside the corresponding side wall of the housing 911, or the air-conduction voice generation unit 910 may be located within the accommodation cavity of the housing 911 and fixedly connected to the housing 911 by a fixing member. Further, a sound conduction hole (not shown) is formed in the housing 911, and the air-conduction sound waves output by the air-conduction voice generation unit 910 may be transmitted to the outside through the sound conduction hole. Regarding the detailed content of the piezoelectric voice generation unit 920 and the air-conduction voice generation unit 910, reference may be made to the content of FIGS. 1 to 5 of this specification. The air-conduction voice generation unit 910 is mainly used for low-frequency (for example, 20 Hz to 500 Hz) output, the bone-conduction voice generation unit 930 is mainly used for intermediate-frequency (for example, 500 Hz to 6 kHz) output, and the piezoelectric voice generation unit 920 is mainly used for high-frequency (for example, 6 kHz to 20 kHz) output. Thereby, the voice output by the acoustic output device 900 can cover from low frequency to high frequency, and the output intensity of the voice within the entire frequency band range is improved, effectively improving the overall sound quality.

[0063] Note that FIGS. 1 to 9 are merely used for illustrative explanations and do not limit the present application. Those skilled in the art can make various changes and modifications based on the description of the present application. Although the beneficial effects achievable by the embodiments are different, in different embodiments, the achievable beneficial effects may be any one or a combination of the above, or any other achievable beneficial effects.

[0064] As described above, the basic concept has been explained. However, it is obvious to those skilled in the art that the above detailed disclosure is merely presented as an example and does not limit the present application. Although not clearly described in this specification, 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 thus within the spirit and scope of the exemplary embodiments of the present application.

[0065] Furthermore, specific terms are used in the present application to describe the embodiments. For example, "one embodiment", "an embodiment", and / or "some embodiments" mean specific features, structures, or characteristics related to at least one embodiment of the present application. Therefore, it should be emphasized and understood that two or more references to "an embodiment" or "one embodiment" or "one alternative embodiment" in different parts of this specification do not necessarily refer to the same embodiment. Also, the specific features, structures, or characteristics in one or more embodiments of the present application can be appropriately combined.

[0066] Also, unless expressly recited in the claims, the recited order of process elements or sequences, the use of alphanumerics, or the use of other names in this application do not limit the order of the procedures and methods of this application. In the above disclosure, various useful examples of the invention, which are currently considered to be, are described through various examples. However, such details are for illustrative purposes only. The appended claims are not limited to the disclosed examples, but rather are intended to cover all modifications and equivalent combinations within the spirit and scope of the examples of this application. For example, the above-described system assembly may be implemented by a hardware device, but may also be implemented by a software-only solution, for example, by installing the system described in an existing server or mobile device.

[0067] Similarly, in the foregoing description of the examples of this application, for the purpose of simplifying the description of the disclosure of this application and assisting in the understanding of one or more embodiments of the invention, various features may be grouped together in one embodiment, drawing, or description thereof. However, such a disclosure method should not be construed as reflecting an intention that the subject matter of this application requires more features than those recited in each claim. In fact, the features of an embodiment may sometimes be fewer than all the features of the single embodiment disclosed above.

[0068] Numbers are used in some embodiments to describe components and attributes, and it should be understood that the numbers used to describe such embodiments are, in some instances, modified by the modifiers "about," "substantially," or "essentially." Unless otherwise specified, "about," "substantially," or "essentially" indicates that the number is allowed to vary up to ±20%. Accordingly, in some embodiments, the numerical parameters used in the specification and claims are all approximate values that can vary according to the characteristics required for a particular embodiment. In some embodiments, for numerical parameters, the specified number of significant digits should be considered and the normal rounding method should be applied. In some embodiments of the present application, the numerical ranges and parameters for determining the range are approximate values, but in specific embodiments, such numbers are set as accurately as possible.

[0069] All patents, patent applications, published patent publications, and other materials such as papers, books, specifications, publications, documents, etc. referred to in the present application are incorporated herein by reference in their entirety, except for application process documents that do not match or conflict with the content of the present application and documents that may have a limiting effect on the broadest scope of the claims of the present application (currently or later related to the present application). In the event that the descriptions, definitions, and / or use of terms in the attached materials of the present application do not match or conflict with the content described in the present application, the descriptions, definitions, and / or use of terms in the present application shall take precedence.

[0070] Finally, it should be understood that the embodiments in the present application are merely for explaining the principles of the embodiments of the present application. Other variations may also be within the scope of the present application. Therefore, without limitation, by way of example, alternative configurations of the embodiments of the present application may be considered to be in accordance with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments clearly introduced and described in the present application.

Description of Reference Numerals

[0071] 100 Acoustic output device 110 Bone conduction voice generation unit 120 Piezoelectric audio generating unit 130 Air-conduction audio generating unit 421 Piezoelectric element 4211 Piezoelectric layer 4212 Base layer 440 Housing 442 Sound conduction hole 522 Vibration transmission element 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 is transmitted to a person's ear through a bone and generates a bone conduction sound wave having at least one resonance peak within a frequency range of 1 kHz or less, and a piezoelectric sound generation unit that generates a sound wave having at least one resonance peak within a frequency range of 6 kHz or more, an acoustic output device.

2. The piezoelectric sound generation unit is installed on a side wall of the housing of the acoustic output device that abuts against a person's face, and generates a bone conduction sound wave and transmits it to the person's face. The acoustic output device according to claim 1.

3. The piezoelectric sound generation unit is installed on the side of the side wall that contacts the person's face facing the person's face or is fitted to the side wall of the housing that contacts the person's face, The piezoelectric sound generation unit is plate-shaped, and an edge portion thereof is fixed to the side wall. The acoustic output device according to claim 1 or 2.

4. The piezoelectric sound generation unit includes a piezoelectric element and a diaphragm connected to the piezoelectric element. The diaphragm is fixed to a side wall that contacts the person's face, and the piezoelectric element vibrates to drive the diaphragm to vibrate to generate a bone conduction sound wave. The acoustic output device according to any one of claims 1 to 3.

5. The piezoelectric sound generation unit is disposed at a position that does not abut against a person's face of the housing of the acoustic output device. Mechanical vibration generated by the piezoelectric sound generation unit is transmitted to the housing, and the piezoelectric sound generation unit or the housing generates a sound wave. The acoustic output device according to claim 1.

6. The piezoelectric sound generation unit has a plate-shaped or strip-shaped structure, one end thereof is connected to the housing of the acoustic output device, and the other end is suspended and installed on the housing. The piezoelectric sound generation unit vibrates to generate an air conduction sound wave. The acoustic output device according to claim 5.

7. The piezoelectric audio generating unit includes a piezoelectric element and a diaphragm connected to the piezoelectric element. The piezoelectric element drives the diaphragm to vibrate to generate an air-conducted sound wave, and the diaphragm is perpendicular to the vibration direction of the bone-conducted audio generating unit. The acoustic output device according to claim 1.

8. The acoustic output device according to claim 7, further comprising an air-conducted audio generating unit that generates an air-conducted sound wave having a resonance peak within a frequency range of 500 Hz or less.

9. The air-conducted audio generating unit includes a diaphragm, and the vibration direction of the diaphragm is perpendicular to the vibration direction of the bone-conducted audio generating unit. The acoustic output device according to claim 8.

10. The piezoelectric audio generating unit vibrates to generate an air-conducted sound wave, and the piezoelectric audio generating unit and the air-conducted audio generating unit are arranged in a stacked manner or in parallel. The vibration direction of the air-conducted audio generating unit is perpendicular to the vibration direction of the bone-conducted audio generating unit. The acoustic output device according to claim 8 or 9.

11. The piezoelectric audio generating unit includes a piezoelectric element, and the bone-conducted audio generating unit and the piezoelectric element are driven to vibrate by the same excitation voltage. The acoustic output device according to any one of claims 1 to 10.

12. The resonance frequency of the piezoelectric audio generating unit has at least one resonance peak within a frequency range of 8 kHz or more. The acoustic output device according to claim 11.

13. The acoustic output device according to claim 11, further comprising a booster circuit that boosts the excitation voltage for driving the piezoelectric element.

14. The piezoelectric audio generating unit generates a sound wave having at least one resonance peak within a frequency range of 7 kHz or more. The acoustic output device according to claim 13.

15. Further comprising a frequency division circuit, wherein the frequency division circuit performs 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 drives the bone conduction sound generating unit, and the signal in the second frequency range drives the piezoelectric sound generating unit, the acoustic output device according to claim 1.

16. Further comprising a booster circuit for boosting the signal in the second frequency range, the acoustic output device according to claim 15.

17. Comprising an air conduction sound generating unit, wherein the frequency division circuit performs frequency division on the signal in the 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 signal in the first sub - frequency range drives the air conduction sound generating unit, the signal in the second sub - frequency range drives the bone conduction sound generating unit, and the second crossover frequency is less than the first crossover frequency, the acoustic output device according to claim 15.

18. The bone conduction sound generating unit includes a magnetic circuit system, a coil, and a vibration transmission sheet, the magnetic circuit system is elastically connected to the housing of the acoustic output device by the vibration transmission sheet. The magnetic circuit system includes a magnet assembly and a magnetic flux conduction cover, the magnetic flux conduction cover is a housing structure with an open - ended opening at one end, the magnet assembly is located within the magnetic flux conduction cover, and has a gap between the magnetic flux conduction cover and the magnet assembly along a direction perpendicular to the vibration direction, and the coil is inserted into the magnetic gap from the opening of the magnetic flux conduction cover, the acoustic output device according to any one of claims 1 to 17.

19. The bone conduction sound generating unit includes a magnetic circuit system, a coil, and a vibration transmission sheet. The magnetic circuit system includes a magnet assembly. The coil is externally fitted outside the magnet assembly around an axis parallel to the vibration direction of the bone conduction sound generating unit. In the vibration direction, the vibration transmission sheet elastically supports the magnet assembly from one side of the magnet assembly. The acoustic output device according to any one of claims 1 to 17.

20. The bone conduction sound generating 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 externally fitted outside the magnet assembly around an axis parallel to the vibration direction of the bone conduction sound generating unit. In the vibration direction, the first vibration transmission sheet and the second vibration transmission sheet elastically support the magnet assembly from opposite sides of the magnet assembly. The acoustic output device according to any one of claims 1 to 17.

21. The magnetic circuit system further includes a magnetic flux conduction cover. The magnet assembly includes a magnet, 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 externally fitted outside 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 externally fitted outside 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. The edge region of the second vibration transmission sheet is connected to the other end of the magnetic flux conduction cover. The acoustic output device according to claim 20.

22. The coil includes a first coil and a second coil. The first coil and the second coil are installed in the magnetic circuit system, and the first coil and the second coil are connected in series or in parallel. The acoustic output device according to claim 21.

23. The magnet assembly includes a first magnet and a second magnet stacked and installed along the vibration direction. The magnetization directions of the first magnet and the second magnet are different. The central region of the first vibration transmission sheet is connected to the side away from the second magnet of the first magnet, and the central region of the second vibration transmission sheet is connected to the side away from the first magnet of the second magnet. The acoustic output device according to claim 20.

24. The magnet assembly further includes a magnetic flux conduction plate interposed between the first magnet and the second magnet. When the coil is orthogonally projected onto the outer peripheral surface of the magnet assembly along a direction perpendicular to the vibration direction, it overlaps with the side peripheral surface of the magnetic flux conduction plate. The acoustic output device according to claim 23.

25. The magnetization directions of the first magnet and the second magnet are opposite, and both are perpendicular to the surface facing the first magnet or the second magnet of the magnetic flux conduction plate. The acoustic output device according to claim 24.

26. The bone conduction voice generation unit further includes a vibration damping sheet and a vibration panel. The bone conduction voice generation unit is suspended in the housing by the vibration damping sheet, and the vibration panel is connected to the bone conduction voice generation unit to transmit the mechanical vibration generated by the bone conduction voice generation unit to a person's face. The acoustic output device according to claim 20.

Images