TW202344073A - Acoustic output device - Google Patents

Abstract

Embodiments in description of the present disclosure provides an acoustic output device including a vibrating element with a beam structure extending along a length direction; a piezoelectric element configured to generate deformation in response to an electrical signal, the deformation driving the vibration element to vibrate, the piezoelectric element being attached to a first position of the beam structure, and size of the attachment area along the length direction being not exceed 80% of size of the beam structure along the length direction; a mass element connected to a second position of the beam structure, the first position and the second position being spaced apart in the length direction, and the vibration of the vibration element driving the mass element to vibrate in a direction perpendicular to the length direction. Sensitivity of the acoustic output device in the low frequency range is improved through the vibration of thevibration elements and the mass element, and a relatively flat vibration response curve in the range from low frequency to high frequency is obtained, thereby improving sound quality of the acoustic output device.

Description

an acoustic output device

This specification relates to the field of acoustic technology, and in particular to an acoustic output device.

Piezoelectric acoustic output devices use the inverse piezoelectric effect of piezoelectric materials to generate vibrations and radiate sound waves outward. Compared with transmission electric speakers, they have the advantages of high electromechanical energy conversion efficiency, low energy consumption, small size, and high integration. . Under the current trend of device miniaturization and integration, piezoelectric acoustic output devices have extremely broad prospects and future. However, piezoelectric acoustic output devices have problems such as poor low-frequency response, resulting in low sensitivity in the low-frequency range (for example, 50Hz-2000Hz).

Therefore, it is desired to provide an acoustic output device to improve the low-frequency response of the piezoelectric acoustic output device, thereby improving the sensitivity of the acoustic output device in the low-frequency range.

Embodiments of this specification provide an acoustic output device, including: a vibrating element having a beam structure extending along the length direction; a piezoelectric element used to deform in response to an electrical signal, and the deformation drives the vibrating element to vibrate, wherein , the piezoelectric element is attached to the first position of the beam structure, and the size of the attachment area along the length direction does not exceed 80% of the size of the beam structure along the length direction; and a mass element, the mass element is connected In the second position of the beam structure, where the first position and the second position are spaced apart in the length direction, the vibration of the vibration element drives the mass element to vibrate in a direction perpendicular to the length direction.

100,1700,1900,200,300,400,700,900: Acoustic output device

1011,1032,1112,1132,1212,1232,1312,1332,1412,1432,1512,1532,1612,1632,1811,1821,2021: resonance peak

1012,1031,1111,1131,1211,1231,1311,1331,1411,1431,1511,1531,1611,1631,2013,2161: Resonance Valley

110:Vibration element

111: Fixed end

111’,112: Free end

120: Piezoelectric element

121,122: Piezoelectric film

130:Quality component

140: Second piezoelectric element

150: Second mass element

160: Second vibration element

170: The third piezoelectric element

180: The third vibration element

190: The fourth piezoelectric element

2012, 2032: Second resonance peak

210: Shell structure

220: Fixed structure

621,811,821,831,2011,2031: first resonance peak

AA’,BB’: arrow

C,M,N,O,P,Q,R,X,Y,Z: dotted circle

d31,d33: working mode

L31,L32,L33,L34,L35,L36,L51,L52,L53,L54,L61,L62,L63,L81,L82,L83,L101,L102,L103,L111,L112,L113,L121,L122,L123, L131,L132,L133,L141,L142,L143,L151,L152,L153,L161,L162,L163,L181,L182,L201,L202,L203,L211,L212,L213,L214,L215,L216,L221,L2 22, L223, L224, L225: Curve

x: length

y:width

z:Thickness

Figure 1 is a structural block diagram of an acoustic output device according to some embodiments of this specification;

Figure 2A is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 2B is a cross-sectional view of the acoustic output device shown in Figure 2A along a direction perpendicular to the length direction of the vibrating element;

Figure 3A is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 3B is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 4 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 5 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 6 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 7 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 8 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 9 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 10 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 11 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 12 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 13 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 14 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 15 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 16 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 17 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 18 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 19 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification;

Figure 20 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 21 is a frequency response curve diagram of an acoustic output device according to some embodiments of this specification;

Figure 22 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In order to explain the technical solutions of the embodiments of this specification more clearly, the drawings needed to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some examples or embodiments of this specification. For those of ordinary skill in the art, without making any progress, they can also make drawings based on these examples. The diagram applies this instruction to other similar situations. Unless obvious from the locale or otherwise stated, the same reference numbers in the figures represent the same structure or operation.

The acoustic output device provided by the embodiments of this specification can utilize the inverse piezoelectric effect to generate vibration through the piezoelectric element to output sound. Generally, piezoelectric elements can adopt two working modes: d33 and d31. In the d33 working mode, the deformation direction of the piezoelectric element (also called the displacement output direction) is the same as the electrical direction (also called the polarization direction). Its resonant frequency is high, the output amplitude is small, and the low-frequency response is poor. In the d31 working mode, the deformation direction of the piezoelectric element is perpendicular to the electrical direction. In the d31 operating mode, although increasing the length of the piezoelectric element can provide a low-frequency peak with a sufficiently low frequency, the output amplitude is also significantly increased, but in this case, the piezoelectric element is in the audible range (for example, 20Hz-20kHz ) There are more vibration modes, which are manifested as more peaks and valleys in the frequency response curve, so the sound quality of the acoustic output device (or piezoelectric speaker) is still poor.

In order to solve the problems of poor low-frequency response of piezoelectric speakers and multiple modes in the audible range, the acoustic output device provided by embodiments of this specification may include a vibrating element, a piezoelectric element, and a mass element. Wherein, the vibrating element has a beam structure extending along the length direction. The piezoelectric element can deform in response to an electrical signal, and the deformation can drive the vibrating element to vibrate. The piezoelectric element is attached to the first position of the beam structure, and the size of the attachment area along the length direction of the beam structure does not exceed 80% of the size of the beam structure along the length direction. The mass element may be connected to the beam structure at a second location. The first position and the second position are spaced apart in the length direction of the beam structure, and the vibration of the piezoelectric element can drive the mass element to vibrate perpendicular to the length direction of the beam structure. The vibration of the vibrating element and the mass element can cause the frequency response curve of the acoustic output device to have a first resonance peak in the low frequency band (for example, 50Hz~2000Hz), thereby improving the sensitivity of the acoustic output device in the low frequency band. In addition, the vibration of the vibration element and the mass element has a second resonance peak in a high frequency band (for example, 2000Hz~20000Hz), and there is at least one resonance valley between the first resonance peak and the second resonance peak, and the first resonance peak or the second resonance peak The amplitude difference between the two resonance peaks and the at least one resonance valley is less than 80dB, thereby obtaining a relatively flat vibration response curve from low frequency to high frequency, thereby improving the sound quality of the acoustic output device.

The acoustic output device provided in the embodiment of this specification is attached to the vibrating element with a beam structure through a piezoelectric element, and uses an elastic mass system composed of the elasticity provided by the beam structure with a certain length and the mass provided by the mass element to output vibration, so that The frequency response curve of the acoustic output device has a resonance peak in the low frequency band, thereby effectively improving the sensitivity of the acoustic output device in the low frequency band. In some embodiments, the acoustic output device provided by the embodiments of this specification can further reduce the vibration mode of the memory in the audible range of the human ear, for example, make the frequency response curve have no or fewer resonance valleys, or reduce The amplitude difference between the resonance peak and the resonance valley makes the frequency response curve of the acoustic output device relatively flat in the audible range, ensuring that the acoustic output device can have better sound quality.

The acoustic output device provided by the embodiment of this specification will be described in detail below with reference to the drawings.

Figure 1 is a structural block diagram of an acoustic output device according to some embodiments of this specification. In some embodiments, the acoustic output device 100 may be a bone conduction acoustic output device, an air conduction acoustic output device, or a bone-air conduction combined acoustic output device. In some embodiments, the acoustic output device 100 may include speakers, headphones, glasses, hearing aids, augmented reality (AR) devices, virtual reality (VR) devices, etc. or other devices with audio playback functions ( Such as mobile phones, computers, etc.). In some embodiments, the acoustic output device 100 may include a vibrating element 110 , a piezoelectric element 120 , and a mass element 130 .

The vibration element 110 can generate vibration based on the deformation of the piezoelectric element 120 , so that the acoustic output device 100 can output vibration through the mass element 130 . For example, the piezoelectric element 120 can deform in response to an electrical signal. The deformation of the piezoelectric element 120 can drive the vibrating element 110 to vibrate along the polarization direction of the piezoelectric element 120, thereby driving the mass element 130 along the piezoelectric element 120. vibration in the polarization direction. In some embodiments, the vibration direction of the mass element 130 is perpendicular to the length direction of the vibration element 110 . In a In some embodiments, the vibration element 110 may have a beam structure extending along the length direction, the piezoelectric element 120 may be attached to a first position of the beam structure, and the mass element 130 may be connected to a second position of the beam structure. The first position and the second position are spaced apart in the length direction of the vibrating element 110 (or the beam structure). For example, the first position and the second position may be respectively located at both ends of the length direction of the beam structure. For another example, the first position may be located at the center of the beam structure in the length direction, and the second position may be located at any end of the beam structure in the length direction. For another example, the first position and the second position may be located at any two positions in the length direction of the beam structure, and there is a preset distance between the first position and the second position.

In some embodiments, the piezoelectric element 120 can be directly attached to the first position of the vibration element 110 through adhesive bonding. In some embodiments, the piezoelectric element 120 can be connected to the first position of the vibrating element 110 through snapping, buckling, etc. methods. In some embodiments, the piezoelectric element 120 can be attached to the first position of the vibrating element 110 through physical deposition or chemical deposition. In some embodiments, the mass element 130 can be connected to the second position of the vibration element 110 through gluing, snapping, welding, threaded connection, etc.

In some embodiments, the size of the attachment area of the piezoelectric element 120 and the first position of the beam structure (ie, the actual contact surface between the piezoelectric element 120 and the vibration element 110 ) along the length direction of the beam structure can be adjusted so that The range of the flat curve of the frequency response curve of the acoustic output device 100 in the audible range of the human ear is increased, thereby effectively improving the sound quality of the acoustic output device 100 . In some embodiments, in order to ensure the sound quality of the acoustic output device 100, the high-order modes (or vibration modes) of the acoustic output device 100 in the audible range of the human ear are reduced, and the frequency response curve of the acoustic output device 100 is increased. The flat curve range can be achieved by reducing the size of the attachment area of the piezoelectric element 120 and the first position of the beam structure along the length direction of the beam structure. In some embodiments, in order to ensure that the resonance peak of the acoustic output device 100 in the low frequency band can have a higher peak, thereby improving the sensitivity of the acoustic output device 100 in the low frequency band, the length of the beam-like structure of the piezoelectric element 120 cannot be too long. short. In some embodiments, the size of the attachment area of the piezoelectric element 120 and the first position of the beam structure along the length direction of the beam structure may be in the range of 3 mm to 30 mm. In some embodiments , the size of the attachment area of the piezoelectric element 120 and the first position of the beam structure along the length direction of the beam structure may be in the range of 5 mm to 20 mm.

In some embodiments, the resonant frequency and amplitude corresponding to the resonant peak generated by the acoustic output device 100 in the low frequency band can be adjusted by adjusting the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure to adapt to more scene and is beneficial to improving the sensitivity of the acoustic output device 100 in the low frequency band. In order to ensure that the acoustic output device 100 can generate a resonance peak (i.e., the first resonance peak) in a lower frequency band, thereby improving the sensitivity of the acoustic output device in the low frequency band, in some embodiments, the piezoelectric element 120 and the beam The size of the attachment area of the first position of the structure along the length direction of the beam structure may not exceed 80% of the size along the length direction of the beam structure. In some embodiments, the size of the attachment area of the piezoelectric element 120 and the first position of the beam structure along the length direction of the beam structure may not exceed 60% of the size along the length direction of the beam structure. In some embodiments, as the size of the piezoelectric element 120 decreases along the length direction of the beam structure, its output force may decrease accordingly, resulting in a decrease in the peak value of the resonance peak generated by the acoustic output device 100 in the low frequency band. In order to ensure that the resonant peak of the acoustic output device 100 in the low frequency band has a higher peak, thereby improving the sensitivity in this frequency band, in some embodiments, the attachment area of the piezoelectric element 120 is along the length direction of the beam structure. The size can be greater than 10% of the lengthwise size of the beam structure. In some embodiments, the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure may be greater than 30% of the size along the length direction of the beam structure.

In some embodiments, the damping coefficient of the acoustic output device 100 can also be increased by adding damping to one or more elements in the acoustic output device 100, so that the frequency response curve of the acoustic output device 100 can be heard by the human ear. The listening range is smoother (eg, curve L63 shown in FIG. 6 ) to improve the sound quality of the acoustic output device 100 . For example, the vibration element 110 can be prepared using materials with damping effects (eg, silicone, rubber, foam, etc.). As another example, a damping material may be coated on the piezoelectric element 120 . For another example, the vibration element 110 and/or the mass element 130 can be filled with damping material or electromagnetic damping.

In some embodiments, the vibration element 110 may also be a sheet-shaped, rod-shaped structure, etc. In some embodiments, the material of the vibration element 110 may be a material that has the ability to transmit vibration. For example, the material of the vibration element 110 can be silicone, foam, plastic, rubber, metal, etc., or any combination thereof. In some embodiments, the vibration element 110 may be a component with good elasticity (that is, easy to undergo elastic deformation). For example, the vibration element 110 may include a spring (such as an air spring, a mechanical spring, an electromagnetic spring, etc.), a vibration transmitting piece, an elastic piece, a substrate, etc., or any combination thereof.

The piezoelectric element 120 may be an electrical energy conversion device capable of converting electrical energy into mechanical energy using the inverse piezoelectric effect. In some embodiments, the piezoelectric element 120 may be composed of materials with piezoelectric effect (inverse piezoelectric effect) such as piezoelectric ceramics, piezoelectric quartz, piezoelectric crystals, and piezoelectric polymers. In some embodiments, the piezoelectric element 120 can be in the shape of a sheet, annular, prismatic, rectangular, columnar, spherical, etc., or any combination thereof, or can be in other irregular shapes. In some embodiments, the piezoelectric element 120 may have a beam structure, a sheet structure, a block structure, etc. along its length direction. In some embodiments, the piezoelectric element 120 and the vibration element 110 may be beam structures with the same width. In some embodiments, the piezoelectric element 110 can be an integral structure, and the piezoelectric element 120 is located on one side of the vibrating element 110. When the piezoelectric element 120 deforms along the polarization direction of the piezoelectric element 120, it can drive the vibrating element. 110 vibrates in the same direction, that is, the piezoelectric element 120 can operate in the d33 mode. In some embodiments, the piezoelectric element 120 may include two layers of piezoelectric sheets, and the two layers of piezoelectric sheets are respectively attached to opposite sides of the vibrating element. When the piezoelectric element 120 deforms along the polarization direction perpendicular to the piezoelectric element 120 , the vibration element 110 can generate vibration along the polarization direction of the piezoelectric element 120 according to the deformation of the two layers of piezoelectric sheets, that is, the piezoelectric element 120 Can work in d31 mode. More description of the piezoelectric element 120 can be found in FIGS. 2A and 2B and their description.

The mass element 130 may be a mass block with a certain mass. In some embodiments, the mass element 130 may include a vibration plate, a diaphragm, etc., so that the acoustic output device 100 can output vibration through the mass element 130 . In some embodiments, the mass element The material of 130 may include but is not limited to metals (for example, copper, iron, magnesium, aluminum, tungsten, etc.), alloys (aluminum alloy, titanium alloy, tungsten alloy, etc.), polymer materials (for example, polytetrafluoroethylene, silicone rubber) etc.) and other materials.

The piezoelectric element 120 can deform under the action of a driving voltage (or electrical signal). This deformation can drive the vibration element 110 to vibrate, thereby driving the mass element 130 to vibrate. In some embodiments, the vibrating element 110 and the mass element 130 can resonate to generate a first resonance peak (for example, the first resonance peak 621 shown in FIG. 6 ), thereby improving the sensitivity of the acoustic output device 100 in the low frequency band. .

In some embodiments, the resonant frequency corresponding to the first resonance peak generated by the resonance of the vibrating element 110 and the mass element 130 can be determined according to formula (1):

Among them, f ₀ represents the resonant frequency, k represents the elastic coefficient of the vibration element 110 , and m represents the mass of the mass element 130 .

In some embodiments, according to formula (1), the frequency range of the resonant frequency corresponding to the first resonance peak can be adjusted by adjusting the mass of the mass element 130 and/or the elastic coefficient of the vibration element 110 . In some embodiments, the frequency range of the first resonance peak may be 50 Hz-2000 Hz. In some embodiments, the frequency range of the first resonance peak may be 150 Hz-500 Hz.

In some embodiments, the vibrations of the vibration element 110 and the mass element 130 may have a second resonance peak (eg, the second resonance peak 622 shown in FIG. 6 ). In some embodiments, the second resonance peak may be generated by resonance of the vibrating element 110 with the mass element 130 (eg, a higher order resonance than the resonance that generated the first resonance peak). In some embodiments, the ratio of the frequency of the second resonance peak to the frequency of the first resonance peak may be greater than 5. For example, the frequency of the first resonance peak may be between 50Hz and 200Hz, and the frequency of the second resonance peak may be between 500Hz and 2000Hz. For another example, the frequency of the first resonance peak may be between 100Hz and 500Hz, and the frequency of the second resonance peak may be between 500Hz and 5000Hz. In some embodiments, the vibration of the vibration element 110 and the mass element 130 may generate at least one resonance valley between the first resonance peak and the second resonance peak. In some embodiments, the amplitude difference between the first resonance peak or the second resonance peak and the at least one resonance valley may be less than a preset threshold. For example, the amplitude difference between the first resonance peak or the second resonance peak and the at least one resonance valley may be less than 200 dB. For another example, the amplitude difference between the first resonance peak or the second resonance peak and the at least one resonance valley may be less than 80 dB. For another example, the amplitude difference between the first resonance peak or the second resonance peak and the at least one resonance valley may be less than 50 dB. In some embodiments, the amplitude difference between the first resonant peak or the second resonant peak and the at least one resonant valley is less than a preset threshold, and a relatively flat frequency response curve between the first resonant peak or the second resonant peak can be obtained. , thereby improving the sound quality of the acoustic output device 100. In some embodiments, the ratio of the frequency of the second resonance peak to the frequency of the first resonance peak is greater than 5, which can increase the flat curve between the first resonance peak and the second resonance peak in the frequency response curve of the acoustic output device 100 range, thereby improving the sound quality of the acoustic output device 100.

In some embodiments, the elastic coefficient of the vibration element 120 can be adjusted by adjusting the length of the vibration element 110 (beam structure), thereby adjusting the frequency range of the resonant frequency corresponding to the first resonance peak. For example, the greater the length of the beam structure, the smaller its elastic coefficient. When the mass of the mass element 130 is constant, the resonant frequency corresponding to the first resonance peak is lower. However, if the length of the beam structure is too large, it will be detrimental to the miniaturization design of the acoustic output device 100 . In order to ensure that the acoustic output device 100 can generate the first resonance peak in the low frequency band, thereby improving the sensitivity in this frequency band and miniaturizing the device, in some embodiments, the length of the beam structure may be less than 20 mm. In some embodiments, the length of the beam structure may be less than 50 mm.

In some embodiments, the frequency range of the resonant frequency corresponding to the first resonant peak can be adjusted by adjusting the mass of the mass element 130 . For example, when the length of the beam structure is constant, the greater the mass of the mass element 130, the smaller the resonant frequency corresponding to the first resonant peak. However, if the mass of the mass element 130 is too large, it will be detrimental to the miniaturization design of the acoustic output device 100 . In order to ensure that the acoustic output device 100 can The first resonance peak can be generated, thereby improving the sensitivity in this frequency band and miniaturizing the device. In some embodiments, the mass of the mass element 130 can be less than 8g.

In some embodiments, the vibration of the vibration element 110 (acoustic output device 100) can be transmitted to the user through the mass element 130 in a bone conduction manner. As an example, the vibration of the vibrating element 110 is transmitted through the mass element 130 to the bones and/or muscles of the user's face, and finally to the user's ears. For another example, the mass element 130 may not be in direct contact with the human body. The vibration of the vibration element 110 can be transmitted to the shell of the acoustic output device through the mass element 130, and then transmitted from the shell to the user's facial bones and/or muscles, and finally transmitted to the user. the person’s ears. In some embodiments, the vibration of the vibration element 110 can also be transmitted to the user through the mass element 130 in an air conduction manner. For example, the mass element 130 can directly drive the air around it to vibrate, thereby transmitting the vibration to the user's ear through the air. For another example, the mass element 130 can be further connected to the diaphragm, and the vibration of the mass element 130 can be transmitted to the diaphragm, and then the diaphragm drives the air to vibrate, thereby transmitting it to the user's ear through the air.

In some embodiments, the acoustic output device 100 may also include a second piezoelectric element 140 . The second piezoelectric element 140 may have a similar structure, material, etc. as the piezoelectric element 120 (or referred to as the first piezoelectric element 120). The second piezoelectric element 140 is attached to the third position of the beam structure. The piezoelectric element 120 and the second piezoelectric element 140 can be spaced apart in the length direction of the vibrating element, and the piezoelectric element 120 and the second piezoelectric element 140 The input electrical signals are the same, so the piezoelectric element 120 and the second piezoelectric element 140 can be regarded as being connected in series. In some embodiments, the piezoelectric element 120 and the second piezoelectric element 140 may be in the d31 working mode, and the deformation direction of the piezoelectric element 120 and the second piezoelectric element 140 may be perpendicular to the vibration direction of the vibration element 110 . For example, the piezoelectric element 120 and the second piezoelectric element 140 undergo reciprocating deformation along a direction perpendicular to the polarization direction, driving the vibration element 110 to vibrate along the polarization direction. In some embodiments, the beam structure may include a fixed end and a free end (that is, the vibrating element 110 is a cantilever beam structure), wherein the fixed end may be fixed to other components of the acoustic output device 100 (for example, on the inner wall of the housing), and the free end may End can be compared with mass element Piece 130 connection. In some embodiments, by adjusting the spacing between the piezoelectric element 120 and the second piezoelectric element 140 in the length direction of the beam structure, higher-order modes generated when the vibrating element 110 and the mass element 130 vibrate can be reduced or eliminated. For example, the resonance peak (or resonance valley) generated by the vibration of the vibrating element 110 and the mass element 130 driven by the piezoelectric element 120 in the mid-to-high frequency range (for example, 500Hz-2000Hz) can be consistent with the vibration of the vibrating element 110 and the mass element. 130 The vibrations driven by the second piezoelectric element 140 merge with the resonance valleys (or resonance peaks) generated in the mid-to-high frequency band (for example, 500Hz-2000Hz), thereby eliminating the vibration of the acoustic output device 100 in the mid- to high-frequency band. The high-order modes in the frequency response curve make the frequency response curve smoother, ensuring that the sound quality of the acoustic output device 100 can be improved. In some embodiments, the resonance valleys and resonance peaks that can be merged may refer to resonance valleys and resonance peaks with similar or identical frequencies. For more description about the second piezoelectric element 140 of the acoustic output device 100, please refer to FIG. 9 and its related descriptions, which will not be described again here.

In some embodiments, the acoustic output device 100 may also include a second mass element 150 . Among them, in the length direction of the vibration element 110, the mass element 130 (also called the first mass element 130) and the second mass element 150 can be located on both sides of the piezoelectric element 120 respectively. In some embodiments, by making the second mass element 150 have a greater mass than the mass element 130 , the beam structure can be fixed toward one side of the second mass element 150 (that is, equivalent to the fixed end above), thereby solving the problem that the beam The fixed end of the structure is difficult to find a fixed boundary within the acoustic output device 100 (for example, a housing) and is not easily fixed. In some embodiments, by adjusting the ratio between the mass of the second mass element 150 and the mass of the mass element 130 , the resonant frequency corresponding to the first resonant peak can be adjusted. For more description about the acoustic output device 100 also including the second mass element 150, please refer to FIG. 7 and its related description, which will not be described again here.

In some embodiments, the piezoelectric element 120 may be in the working mode of d33, and the deformation direction of the piezoelectric element 120 may be parallel to the vibration direction of the vibrating element 110 . For example, when the piezoelectric element 120 deforms along the polarization direction of the piezoelectric element 120, This deformation can drive the vibrating element 110 to also vibrate along the polarization direction. In some embodiments, one end of the piezoelectric element 120 along the vibration direction is fixed (for example, fixed on other components of the acoustic output device 100, such as the housing), and the other end is connected to the beam structure at the first position (for example, attached to the beam structure). attached to the beam structure). In some embodiments, by adjusting the position of the piezoelectric element 120 on the beam structure, for example, adjusting the ratio between the distance from the first position to the fixed end of the beam structure and the length of the beam structure, the acoustic output device 100 can be adjusted in the low frequency band. The resonance frequency corresponding to the resonance peak in the acoustic output device 100 can be improved in different frequency bands to be suitable for more usage scenarios. For more description about the deformation direction of the piezoelectric element 120 in the acoustic output device 100 being parallel to the vibration direction of the vibrating element 110, please refer to FIG. 4 and its related description, which will not be described again here.

In some embodiments, the acoustic output device 100 may further include a second vibration element 160 , and the vibration element 110 (also referred to as the first vibration element 110 ) and the second vibration element 160 are symmetrically arranged on both sides of the mass element 130 . Among them, the vibration element 110 and the second vibration element 160 are respectively fixedly arranged at one end away from the mass element 130 . In some embodiments, the acoustic output device 100 may further include a third piezoelectric element 170 connected to the second vibration element 160 , wherein the third piezoelectric element 170 and the piezoelectric element 120 are symmetrically arranged on both sides of the mass element 130 , this can be regarded as the third piezoelectric element 170 and the piezoelectric element 120 being connected in parallel. Through this setting, the resonance valley of the frequency response curve of the acoustic output device 100 in the audible range of the human ear can be reduced or eliminated, ensuring that the frequency response curve of the acoustic output device 100 is smoother and has better sound quality. For more description about the acoustic output device also including the second vibration element 160 and the third piezoelectric element 170, please refer to FIG. 17 and its related description, which will not be described again here.

In some embodiments, the acoustic output device 100 may include a third vibration element 180 connected to the mass element 130 . In some embodiments, the ratio of the length of the third vibration element 180 to the length of the vibration element 110 may be greater than 0.7, and the vibration direction of the third vibration element 180 is parallel to the vibration direction of the vibration element 110 . In some embodiments, the acoustic output device 100 may further include a fourth piezoelectric element 190. The fourth piezoelectric element 190 is connected to the third vibration element 180. Wherein, the fourth piezoelectric element 190 is in the d31 working mode, and the deformation direction of the fourth piezoelectric element 190 is perpendicular to the vibration direction of the third vibration element 180 . Therefore, the resonance peak in the low frequency band generated by the vibration of the third vibration element 180 and the mass element 130 can supplement the resonance valley generated by the vibration of the vibration element 110 and the mass element 110 , thereby making the frequency of the acoustic output device 100 higher. The sound curve is smoother and the sound quality is better, and the third vibration element 180 can increase the vibration amplitude of the mass element 130 in the low frequency band, thereby improving the sensitivity of the acoustic output device 100 in the low frequency band. For more description about the acoustic output device including the third vibration element 180 and the fourth piezoelectric element 190, please refer to FIG. 19 and its related description, which will not be described again here.

In some embodiments, the acoustic output device 100 may also include a housing structure 210 . The housing structure 210 may be configured to carry other components of the acoustic output device 100 (eg, the vibrating element 110, the second vibrating element 160, the third vibrating element 180, the piezoelectric element 120, the second piezoelectric element 140, the third piezoelectric element electrical element 170, fourth piezoelectric element 190, mass element 130, second mass element 150, etc., or combinations thereof). In some embodiments, the housing structure 210 may be a closed or semi-enclosed structure with a hollow interior, and other components of the acoustic output device 100 are located within or on the housing structure. In some embodiments, the shape of the housing structure may be a regular or irregular three-dimensional structure such as a cuboid, a cylinder, a truncated cone, or the like. When the user wears the acoustic output device 100, the housing structure may be positioned close to the user's ears. For example, the housing structure may be located peripherally (eg, front or back) of the user's auricle. As another example, the housing structure may be positioned over the user's ear without blocking or covering the user's ear canal. In some embodiments, the acoustic output device 100 may be a bone conduction earphone, and at least one side of the housing structure may be in contact with the user's skin. The acoustic driver element (for example, the combination of the piezoelectric element 120, the vibration element 110 and the mass element 130) in the bone conduction earphone converts the audio signal into mechanical vibration, which can be transmitted to the user through the shell structure and the user's bones. of the auditory nerve. In some embodiments, the acoustic output device 100 may be an air conduction earphone, and at least one side of the housing structure may With or without contact with the user's skin. The side wall of the housing structure includes at least one sound guide hole. The acoustic driver element in the air conduction earphone converts the audio signal into air conduction sound. The air conduction sound can be radiated in the direction of the user's ear through the sound guide hole.

In some embodiments, acoustic output device 100 may include fixed structure 220 . The securing structure 220 may be configured to mount the acoustic output device 100 near the user's ears. In some embodiments, the fixing structure 220 may be physically connected to the housing structure 210 of the acoustic output device 100 (eg, glued, clipped, threaded, etc.). In some embodiments, the housing structure 210 of the acoustic output device 100 may be part of the fixed structure 220 . In some embodiments, the fixing structure 220 may include ear hooks, back hooks, elastic bands, spectacle legs, etc., so that the acoustic output device 100 can be more firmly installed near the user's ears to prevent the user from falling during use. . For example, the securing structure 220 may be an earhook, which may be configured to be worn around the ear region. In some embodiments, the earhook can be a continuous hook and can be elastically stretched to be worn on the user's ear. At the same time, the earhook can also exert pressure on the user's auricle, so that the acoustic output device 100 is firmly fixed at a specific position on the user's ears or head. In some embodiments, the ear loops may be discontinuous straps. For example, an earhook may include a rigid portion and a flexible portion. The rigid part may be made of rigid material (eg, plastic or metal), and the rigid part may be fixed with the housing structure 210 of the acoustic output device 100 through physical connection (eg, snap connection, threaded connection, etc.). The flexible portion may be made of elastic material (eg, cloth, composite, or/and neoprene). As another example, the securing structure 220 may be a neck strap configured to be worn around the neck/shoulder area. For another example, the fixing structure 220 may be a spectacle leg, which is a part of the spectacles and is mounted on the user's ears.

It should be noted that the above description with respect to FIG. 1 is provided for illustrative purposes only and is not intended to limit the scope of this specification. For those of ordinary skill in the art, various changes and modifications can be made based on the guidance of this specification. For example, in some embodiments, the acoustic output device 100 may further include one or more components (eg, a signal transceiver, an interactive module, a battery, etc.). In some embodiments, the acoustic output device One or more components of device 100 may be replaced by other components that perform similar functions. For example, the acoustic output device 100 may not include the fixed structure 220, and the housing structure 210 or a part thereof may have a human ear-adaptive shape (such as a circular ring, an ellipse, a polygon (regular or irregular), a U-shape, a V-shape , semicircular) shell structure so that the shell structure can be hung near the user's ears. Such changes and modifications would not depart from the scope of this specification.

FIG. 2A is a schematic structural diagram of an acoustic output device according to some embodiments of this specification.

As shown in FIG. 2A , the acoustic output device 200 may include a vibration element 110 , a piezoelectric element 120 and a mass element 130 . The vibration element 110 has a beam structure along the length direction (ie, X direction). The piezoelectric element 120 can be attached to the first position of the beam structure, and the mass element 130 can be connected to the free end 112 of the beam structure (ie, the second position). The first position and the second position are spaced apart in the length direction of the beam structure. In some embodiments, the first position may be located anywhere along the length of the beam structure. For example, the first location may be located in the center of the length of the beam structure. For another example, the piezoelectric element 120 may cover the beam structure along the length direction of the beam structure, that is, the first position may cover the beam structure. In some embodiments, the actual contact surface of the piezoelectric element 120 with the beam structure may be referred to as the attachment area of the piezoelectric element 120 . In some embodiments, the resonant frequency and amplitude corresponding to the resonant peak generated by the low-frequency band of the acoustic output device 200 can be adjusted by adjusting the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure to adapt to more The scene is beneficial to improving the sensitivity of the acoustic output device 200 in the low frequency band. For more description on adjusting the size of the attachment area of the piezoelectric element 120, please refer to FIGS. 3A and 3B and their related descriptions, which will not be described again here.

In some embodiments, the vibrating element 110 may have a cantilever beam structure having a fixed end 111 and a free end 112 . The fixed end 111 can be fixed on other components of the acoustic output device 100 (for example, on the inner wall of the housing), and the free end 112 can be connected with the mass element 130 to output vibration. The piezoelectric element 120 can drive the vibrating element 110 and the mass element 130 vibrate along the polarization direction of the piezoelectric element 120 (ie, the Z direction), so that the vibration element 110 and the mass element 130 generate a first resonance peak (or can (called a low-frequency peak), thereby improving the sensitivity of the acoustic output device 200 in the low-frequency band.

In some embodiments, as shown in FIG. 2A , the beam structure (or cantilever beam) may be a cuboid structure. The cuboid structure may have a length along the X direction, a width along the Y direction, and a thickness along the Z direction. It should be noted that the rectangular parallelepiped beam structure shown in FIG. 2A is only used for illustrative purposes and is not intended to limit the scope of protection of this specification. For those of ordinary skill in the art, various changes and modifications can be made based on the guidance of this specification. In some embodiments, the structure, dimensions, and material parameters of the beam structure or at least a portion thereof may be adjusted. For example, the beam structure in this specification may not be limited to the above-mentioned rectangular parallelepiped structure, but may also be of other shapes. For example, the cross-sectional shape of the beam structure along the length direction (i.e., the X direction) may be a triangle, a semicircle, a rhombus, or a pentagon. , hexagon and other regular or irregular shapes. As another example, the width and/or thickness at different locations on the beam structure may be the same or different. As another example, the shapes at different locations on the beam structure can be the same or different.

FIG. 2B is a cross-sectional view of the acoustic output device shown in FIG. 2A along a direction perpendicular to the length direction of the vibrating element (ie, Y direction).

In some embodiments, the deformation direction of the piezoelectric element 120 in the acoustic output device 200 can be parallel to the length direction of the vibrating element 110, thereby driving the vibrating element 110 to generate vibration along the polarization direction of the piezoelectric element 120, that is, the vibrating element The vibration direction of piezoelectric element 110 may be parallel to the polarization direction of piezoelectric element 120 . Specifically, as shown in FIG. 2B , the piezoelectric element 120 may include two piezoelectric sheets (ie, a piezoelectric sheet 121 and a piezoelectric sheet 122 ). The piezoelectric sheet 121 and the piezoelectric sheet 122 can be respectively attached to opposite sides of the vibrating element 110 (the first position), and the polarization directions of the piezoelectric sheet 121 and the piezoelectric sheet 122 are perpendicular to the attachment surface. The vibration element 110 can vibrate perpendicular to the attachment surface in response to the deformation of the piezoelectric sheet 121 and the piezoelectric sheet 122 .

In some embodiments, piezoelectric sheet 121 and piezoelectric sheet 122 may be elements configured to provide a piezoelectric effect and/or an inverse piezoelectric effect. In some embodiments, the piezoelectric sheet can cover one or more surfaces of the vibrating element 110 and deform under the action of the driving voltage to drive the vibrating element 110 to warp, thereby realizing the piezoelectric element 120 to output vibration. For example, along the polarization direction of the piezoelectric element 120 (as shown by arrow BB' in the figure), the piezoelectric sheet 121 and the piezoelectric sheet 122 are respectively attached to opposite sides of the vibrating element 110. The vibrating element 110 can be configured according to the piezoelectric sheet. The expansion and contraction of the piezoelectric element 121 and the piezoelectric piece 122 along the length direction of the piezoelectric element 120 (as shown by the arrow AA' in the figure) generates vibration. Specifically, the piezoelectric sheet (eg, piezoelectric sheet 121) located on one side of the vibrating element 110 can shrink along its length direction, and the piezoelectric sheet (eg, piezoelectric sheet 122) located on one side of the vibrating element 120 can shrink along its length. The vibration element 110 is elongated in the direction, thereby driving the vibration element 110 to warp in the direction perpendicular to its surface (ie, the thickness direction BB') to generate vibration. In some embodiments, the material of the piezoelectric sheets 121 and/or 122 may include piezoelectric ceramics, piezoelectric quartz, piezoelectric crystals, piezoelectric polymers, etc., or any combination thereof.

It should be noted that the piezoelectric element 120 shown in FIG. 2B is only used for illustrative purposes and is not intended to limit the scope of protection of this specification. In some embodiments, the number of piezoelectric sheets in the piezoelectric element 120 may not be limited to the two shown in FIG. 2B. For example, the piezoelectric element 120 may include a piezoelectric piece, which is attached to one side of the vibrating element 110 (the first position) and can deform under the action of the driving voltage, thereby driving the vibrating element 110 to warp. to achieve the piezoelectric element 120 to output vibration.

In some embodiments, the resonant frequency and amplitude corresponding to the resonant peak generated by the acoustic output device in the low frequency band can be adjusted by adjusting the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure to accommodate more scene and is conducive to improving the sensitivity of the acoustic output device in the low frequency band. By way of example only, FIG. 3A is a structural diagram of an acoustic output device according to some embodiments of the present specification. As shown in FIG. 3A , in the acoustic output device 300 , the piezoelectric element 120 starts from the fixed end 111 and covers (attaches to) at least a part of the beam structure (ie, the vibrating element 110 ) along the length direction of the beam structure. In some embodiments, the ratio between the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure and the length of the beam structure may affect the elasticity of the beam structure. For example, when the cross-sectional height of the portion of the beam structure to which the piezoelectric element 120 is attached (referred to as the covered portion) along the length direction (i.e., the X direction) is greater than that of the portion to which the piezoelectric element 120 is not attached (referred to as the uncovered portion), When the cross-section height in the length direction is higher, the flexural modulus of the covered part is greater than that of the uncovered part, that is, the covered part has a higher elastic coefficient than the uncovered part, making it less likely to bend. In some embodiments, as the ratio between the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure and the length of the beam structure increases, the elastic coefficient of the entire beam structure increases, so that the acoustic output device 300 The resonant frequency corresponding to the low-frequency peak in the frequency response curve also increases.

Figure 3B is a frequency response graph of an acoustic output device according to some embodiments of the present specification. As shown in FIG. 3B , curve L31 is when the ratio between the size of the attachment area of the piezoelectric element 120 of the acoustic output device 300 along the length direction of the beam structure and the length of the beam structure (represented by per in FIG. 3B ) is 0.2. frequency response curve. Curve L32 is a frequency response curve when the ratio between the size of the attachment area of the piezoelectric element 120 of the acoustic output device 300 along the length direction of the beam structure and the length of the beam structure is 0.4. Curve L33 is a frequency response curve when the ratio between the size of the attachment area of the piezoelectric element 120 of the acoustic output device 300 along the length direction of the beam structure and the length of the beam structure is 0.6. Curve L34 is a frequency response curve when the ratio between the size of the attachment area of the piezoelectric element 120 of the acoustic output device 300 along the length direction of the beam structure and the length of the beam structure is 0.8. Curve L35 is a frequency response curve when the ratio between the size of the attachment area of the piezoelectric element 120 of the acoustic output device 300 along the length direction of the beam structure and the length of the beam structure is 0.9. Curve L36 is a frequency response curve when the ratio between the size of the attachment area of the piezoelectric element 120 of the acoustic output device 300 along the length direction of the beam structure and the length of the beam structure is 1. The resonance peak in the dotted circle C is the first resonance generated by the acoustic output device 300 in the low frequency band when the size of the attachment area of the piezoelectric element 120 along the length of the beam structure has different ratios to the length of the beam structure. peak.

It can be seen from FIG. 3B that as the ratio between the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure and the length of the beam structure increases, the acoustic output device (eg, the acoustic output device 300 ) The resonant frequency corresponding to the first resonant peak in the low frequency band gradually increases (for example, the resonant frequency corresponding to the first resonant peak in the curve L31-L36 gradually increases). When the ratio between the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure and the length of the beam structure reaches 90%, the resonant frequency corresponding to the first resonant peak in the curve L35 is the same as the first resonant peak in the curve L36 The corresponding resonant frequencies are almost the same, and when the ratio between the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure and the length of the beam structure is 80% or less, curve L34, curve L33, curve L32, The resonance frequency corresponding to the first resonance peak in curve L31 will decrease as the ratio decreases. In order to ensure that the acoustic output device (for example, the acoustic output device 300) can generate a resonance peak (i.e., the first resonance peak) in a lower frequency band, thereby achieving the purpose of improving the sensitivity of the acoustic output device in the low frequency band, in some embodiments , the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure may not exceed 80% of the size along the length direction of the beam structure. In some embodiments, the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure may not exceed 60% of the size along the length direction of the beam structure.

In addition, it can also be seen from FIG. 3B that as the ratio between the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure and the length of the beam structure decreases, the third curve in the curve L36-L31 The peak value corresponding to a resonance peak decreases. This is because the size of the piezoelectric element 120 along the length direction of the beam structure decreases, resulting in a decrease in its output force, resulting in a decrease in the peak value of the resonance peak. In order to ensure that the resonance peak of the acoustic output device in the low frequency band can have a higher peak, thereby improving the sensitivity in this frequency band, in some embodiments, the attachment area of the piezoelectric element 120 is along the length direction of the beam structure. The dimensions may be greater than 10% of the length of the beam structure. In some embodiments, the size of the attachment area of the piezoelectric element 120 along the length direction of the beam structure may be greater than 30% of the size along the length direction of the beam structure.

Figure 4 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification.

As shown in FIG. 4 , the acoustic output device 400 and the acoustic output device 200 have similar structures. The difference lies in the arrangement and working mode of the piezoelectric element 120 in the acoustic output device 400 and the piezoelectric element 110 in the acoustic output device 200 . . In the acoustic output device 400 , when the piezoelectric element 120 is in the working mode of d33, the deformation direction of the piezoelectric element 120 may be parallel to the vibration direction of the vibrating element 110 . Specifically, in the acoustic output device 400 , the piezoelectric element 120 is attached to one side of the vibrating element 110 along the vibration direction of the vibrating element 110 . Further, one end of the piezoelectric element 120 is fixed along the polarization direction, and the other end is connected (attached) to the beam structure at the first position. Through this arrangement, when the piezoelectric element 120 is deformed along its polarization direction, the vibrating element 110 can be driven to vibrate in the same direction. In some embodiments, the piezoelectric element 120 may have a stacked structure. As an exemplary illustration, the piezoelectric element 120 may include multiple layers of piezoelectric sheets, and the multiple layers of piezoelectric sheets may be stacked along the polarization direction of the piezoelectric sheets to form the piezoelectric element 120 .

In some embodiments, the distance between the fixed end 111 and the piezoelectric element 120 (or the first position) is different along the length direction of the beam structure, and the frequency response curve of the acoustic output device 400 resonates in the low frequency band. The resonance frequencies corresponding to the peaks are different. The first position here may refer to the position of the edge of the piezoelectric element 120 close to the fixed end 111 . Therefore, by adjusting the distance between the fixed end 111 and the piezoelectric element 120 in the length direction of the beam structure, the resonant frequency corresponding to the resonance peak in the low frequency band of the frequency response curve of the acoustic output device 400 can be changed, thereby benefiting the acoustics. The sensitivity of the output device in different frequency bands has been improved to suit more scenarios. A detailed description will be given below in conjunction with the frequency response curve of the acoustic output device.

Figure 5 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In FIG. 5 , curve L51 is a frequency response curve when the ratio of the distance between the fixed end 111 of the acoustic output device 400 and the piezoelectric element 120 to the length of the beam structure (represented by p in FIG. 5 ) is 0.2. Curve L52 is the fixed end of the acoustic output device 400 The frequency response curve when the ratio of the distance between 111 and the piezoelectric element 120 to the length of the beam structure is 0.4. Curve L53 is a frequency response curve when the ratio of the distance between the fixed end 111 of the acoustic output device 400 and the piezoelectric element 120 to the length of the beam structure is 0.6. Curve L54 is a frequency response curve when the ratio between the fixed end 111 of the acoustic output device 400 and the piezoelectric element 120 and the length of the beam structure is 0.8. The resonance peak in the dotted circle Y is the first resonance peak generated by the acoustic output device 400 in the low frequency band.

It can be seen from Figure 5 that when the distance between the piezoelectric element in the acoustic output device (for example, the acoustic output device 400) and the fixed end increases, the resonant frequency corresponding to the resonance peak of the acoustic output device in the low frequency band It is also increasing (for example, the resonant frequency corresponding to the resonant peak in curve L51, curve L52, curve L53 and curve L54 gradually increases). In order to ensure that the acoustic output device (for example, the acoustic output device 400) can generate the first resonance peak in the low frequency band, thereby improving the sensitivity in this frequency band, in some embodiments, the distance between the first position and the fixed end is equal to the distance between the first position and the fixed end of the beam. The ratio between the lengths of structures can be less than 0.6. In some embodiments, the ratio between the distance between the first position and the fixed end and the length of the beam structure may be less than 0.4.

Figure 6 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

As shown in FIG. 6 , curve L61 is when the damping coefficient (expressed by eta in FIG. 6 ) of the acoustic output device (for example, the acoustic output device 400 ) is 0, the fixed end of the acoustic output device (for example, the fixed end 111 ) and the piezoelectric The frequency response curve of the acoustic output device when the ratio of the distance between the elements 120 to the length of the beam structure (represented by p in FIG. 6 ) is 0.2 and the piezoelectric element 120 is in the d33 operating mode. Curve L62 is when the damping coefficient of the acoustic output device (eg, the acoustic output device 200 ) is 0, the ratio of the distance between the fixed end of the acoustic output device and the piezoelectric element 120 to the length of the beam structure is 0.2, and the piezoelectric element 120 is at d31 Frequency response curve of the acoustic output device in working mode and when the width of the piezoelectric element 120 is 2 mm. Curve L63 is the relationship between the fixed end of the acoustic output device (eg, the acoustic output device 200 ) and the damping coefficient 1, and the piezoelectric element 120 . The frequency response curve of the acoustic output device when the ratio of the distance to the length of the beam structure is 0.2, the piezoelectric element 120 is in the d31 operating mode, and the width of the piezoelectric element 120 is 2 mm. In some embodiments, the width of piezoelectric element 120 may be the same as the width of the beam structure. The first resonance peak (or low frequency peak) in the dotted circle X may be generated by the resonance of the vibration element 110 and the mass element 130 . This first resonance peak is beneficial to improving the sensitivity of the acoustic output device 200 in the low frequency band.

As shown in FIG. 6 , in some embodiments, the vibration element 110 and the mass element 120 can generate a first resonance peak in the range of 50Hz-2000Hz. In some embodiments, the vibration element 110 and the mass element 120 may generate a first resonance peak in the range of 200Hz-2000Hz. In some embodiments, the vibration element 110 and the mass element 120 may generate a first resonance peak in the range of 500Hz-1000Hz.

Combining curve L61 and curve L62, it can be seen that when the piezoelectric element 120 is in the d31 working mode, the acoustic output device can generate a first resonance peak with a higher peak value in the low frequency band than when the piezoelectric element 120 is in the d33 working mode. Therefore, in some embodiments, by placing the piezoelectric element 120 in the d31 operating mode, the sensitivity of the acoustic output device in the low frequency band can be improved.

In some embodiments, a damping structure can be added to the acoustic output device to increase the damping coefficient of the acoustic output device so that the vibration response curve of the acoustic output device is relatively smooth, thereby further improving the sound quality of the acoustic output device. For example, the vibrating element 110 may be made using a damping material (eg, nitrile). For another example, a damping material can be added to the vibrating element 110 , for example, damping paint is coated on the surface of the vibrating element 110 or penetrates into the interior of the vibrating element 110 . Combining curve L62 and curve L63, it can be seen that L63 is smoother than L62, but the peak value of the first resonance peak of curve L61 is significantly smaller than the peak value of the first resonance peak of L63. Therefore, in some embodiments, by appropriately increasing the damping coefficient of the acoustic output device, its frequency response curve can be made flatter, allowing it to have better sound quality. However, when the damping coefficient of the acoustic output device is too large, it will cause the first resonance peak of the acoustic output device in the low frequency band to decrease, resulting in the sensitivity of the acoustic output device in the low frequency band. Sensitivity is reduced. In order to ensure that the acoustic output device has good sound quality and good sensitivity in the low frequency band, in some embodiments, the damping coefficient of the acoustic output device may be 0-1. In some embodiments, the acoustic output device may have a damping coefficient of 0.2-0.5.

Figure 7 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification.

As shown in FIG. 7 , the structure of the acoustic output device 700 can be regarded as a change based on the structure of the acoustic output device 200 . Specifically, the difference between the acoustic output device 700 and the acoustic output device 200 is that the fixed end 111 in the acoustic output device 200 is set as a free end 111' in the acoustic output device 700. In addition, the acoustic output device 700 may also include a second mass element. 150. Wherein, in the length direction of the vibration element 110, the mass element 130 and the second mass element 150 may be located on both sides of the piezoelectric element 120 respectively. As an example, the mass element 130 and the second mass element 150 can be connected to both ends of the beam structure in the length direction, for example, the second mass element 150 is connected to the free end 111', and the mass element 130 is connected to the free end 112.

In some embodiments, the masses of mass element 130 and second mass element 150 may be the same or different. As shown in FIG. 1 , the frequency range of the resonant frequency corresponding to the first resonant peak can be adjusted by adjusting the mass of the mass element 130 . When the length of the beam structure is constant, the greater the mass of the mass element 130, the smaller the resonant frequency corresponding to the first resonant peak. In some embodiments, in order to obtain the first resonance peak in a lower frequency range, thereby improving the sensitivity of the acoustic output device 100 in the low frequency band, the mass of the mass element 130 may be less than 5g. In some embodiments, in order to obtain the first resonance peak in a lower frequency range, thereby improving the sensitivity of the acoustic output device 100 in the low frequency band, the mass of the mass element 130 may be less than 8g. In some embodiments, in order to obtain the first resonance peak in a lower frequency range, thereby improving the sensitivity of the acoustic output device 100 in the low frequency band, the mass of the mass element 130 may be less than 10 g.

8 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In FIG. 8 , curve L81 indicates that the mass of the second mass element 150 of the acoustic output device 700 is much smaller than the mass of the mass element 130 (which can be approximately regarded as the ratio of the mass of the second mass element 150 to the mass of the mass element 130 ( FIG. 8 np is used to represent the frequency response curve when ) is 0). Curve L82 is a frequency response curve when the ratio of the mass of the second mass element 150 to the mass of the mass element 130 of the acoustic output device 700 is 2. Curve L83 is a frequency response curve when the ratio of the mass of the second mass element 150 to the mass element 130 of the acoustic output device 700 is 100.

It can be seen from FIG. 8 that as the ratio of the mass of the second mass element 150 to the mass of the mass element 130 increases, the first resonance peak 811 on the curve L81, the first resonance peak 821 on the curve L82 and the curve L83 The resonant frequencies corresponding to the first resonant peaks 831 are gradually decreasing. As an example, as shown in FIG. 8 , the resonant frequency corresponding to the first resonant peak 811 is about 350 Hz, the resonant frequency corresponding to the first resonant peak 821 is about 250 Hz, and the resonant frequency corresponding to the first resonant peak 831 is about 75 Hz. Therefore, in some embodiments, in order to ensure that the acoustic output device 700 generates the first resonance peak in a lower frequency band, the mass of the second mass element 150 may be greater than the mass of the mass element 130 . Furthermore, by adjusting the ratio between the mass of the second mass element 150 and the mass of the mass element 130, the resonant frequency corresponding to the resonant peak of the acoustic output device 700 can be changed. Specifically, the greater the ratio between the mass of the second mass element 150 and the mass of the mass element 130 , the smaller the resonant frequency corresponding to the resonant peak of the acoustic output device 700 is. In some embodiments, in order to ensure that the acoustic output device 700 generates the first resonance peak in the low frequency band, the ratio between the mass of the second mass element 150 and the mass of the mass element 130 may be in the range of 0-5. In some embodiments, in order to ensure that the acoustic output device 700 generates the first resonance peak in the low frequency band, the ratio between the mass of the second mass element 150 and the mass of the mass element 130 may be in the range of 0-10. In some embodiments, in order to ensure that the acoustic output device 700 generates the first resonance peak in the low frequency band, the ratio between the mass of the second mass element 150 and the mass of the mass element 130 may be in the range of 0-50.

In some embodiments, in the acoustic output device 700, when the mass of the second mass element 150 is much greater than the mass of the mass element 130 (for example, the ratio between the mass of the second mass element 150 and the mass element 130 is greater than or equal to 100) When , the vibration element 110 (beam structure) can be fixed toward one end of the second mass element 150 , and the end of the beam structure connected to the second mass element 150 can be regarded as a fixed end. At this time, the acoustic output device 700 can be equivalent to an acoustic output Device 200. Through this arrangement, the second mass element 150 can be used as a fixed boundary (fixed end) of the beam structure, thereby solving the problem that it is difficult to find a fixed boundary for fixing the fixed end of the beam structure in the acoustic output device (for example, within the shell structure). problem.

In some embodiments, in the acoustic output device 700 , when the mass of the second mass element 150 is much greater than the mass of the mass element 130 , the acoustic output device 700 may be equivalent to the acoustic output device 200 . Therefore, according to the relevant description of the acoustic output device 200, in order to ensure that the acoustic output device 700 can generate the first resonance peak in the low frequency band, the distance between the second mass element 150 and the piezoelectric element 120 and the length of the beam structure must be The ratio can be less than 0.8. In some embodiments, the ratio between the distance between the second mass element 150 and the piezoelectric element 120 and the length of the beam structure may be less than 0.4.

Figure 9 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification.

As shown in FIG. 9 , the structure of the acoustic output device 900 can be regarded as a change based on the structure of the acoustic output device 200 . Specifically, the difference between the acoustic output device 900 and the acoustic output device 200 is that the acoustic output device 900 may further include a second piezoelectric element 140 . The second piezoelectric element 140 may be attached to the third position of the beam structure, wherein the piezoelectric element 120 and the second piezoelectric element 140 may be spaced apart in the length direction of the vibrating element 110 (or referred to as the beam structure).

In some embodiments, the second piezoelectric element 140 and the piezoelectric element 120 may have the same or similar structure, material, etc. In some embodiments, the piezoelectric element 120 and the second piezoelectric element 140 are in the length direction of the vibrating element 110 (or referred to as the beam structure). They are arranged at intervals, and the electrical signals input to the piezoelectric element 120 and the second piezoelectric element 140 can be the same, so that the piezoelectric element 120 and the second piezoelectric element 140 can be regarded as being connected in series. In some embodiments, the second piezoelectric element 140 and the piezoelectric element 120 may be in the d31 working mode, and the deformation direction of the piezoelectric element 120 and the second piezoelectric element 140 may be perpendicular to the vibration direction of the vibration element 110 .

In some embodiments, the piezoelectric element 120 and the second piezoelectric element 140 may be located on the same side of the beam structure in the vibration direction of the vibration element 110 . For example, as shown in FIG. 9 , the piezoelectric element 120 and the second piezoelectric element 140 can be respectively attached to the first position and the third position of the beam structure and located on the same side of the beam structure. In some embodiments, the piezoelectric element 120 and the second piezoelectric element 140 may be located on opposite sides of the beam structure in the vibration direction of the vibration element 110 . For example, the piezoelectric element 120 and the second piezoelectric element 140 can be attached to the first and third positions of the beam structure respectively and located on opposite sides of the beam structure.

It should be noted that the number of piezoelectric elements shown in FIG. 9 is only for illustrative purposes and is not intended to limit the scope of protection of this specification. In some embodiments, the acoustic output device 900 may also include more than two piezoelectric elements, for example, 3, 4, 5, etc. Wherein, two or more piezoelectric elements can be arranged at intervals in the length direction of the beam structure. In some embodiments, the distance between two adjacent piezoelectric elements among the two or more piezoelectric elements in the length direction of the beam structure may be the same or different. In some embodiments, as shown in FIG. 9 , piezoelectric element 120 and second piezoelectric element 140 may be located on the same side of mass element 130 . In some embodiments, the piezoelectric element 120 and the second piezoelectric element 140 can also be located on both sides of the mass element 130 respectively. For example, in the length direction of the beam structure, the piezoelectric element 120, the mass element 130 and the second piezoelectric element 140 are arranged in sequence.

The acoustic output device 900 will be described in detail below with reference to the frequency curve diagram of the acoustic output device 900 .

Figure 10 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

FIG. 10 shows that when the length of the beam structure of the acoustic output device 900 is 50 mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 (that is, the attachment area of the piezoelectric element 120 and the beam structure along the length direction of the beam structure) size) are both 5mm, and the piezoelectric element 120 or the second piezoelectric element 140 is 4mm away from the fixed end (indicated by p1 in the figure), the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure Different frequency response curves of the acoustic output device 900 with different distances (indicated by p12 in the figure). The distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure may refer to the distance between the center point (eg, centroid) of the piezoelectric element 120 and the center point of the second piezoelectric element 140 distance. Among them, curve L101, curve L102 and curve L103 are the frequency response curves of the acoustic output device 900 when the distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure are 14 mm, 18 mm and 22 mm respectively. The dotted circle Z represents the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz). In some embodiments, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure may refer to the separation area between the piezoelectric element 120 and the second piezoelectric element 140 in the length direction of the beam structure. length.

It can be seen from Figure 10 that when the length of the beam structure of the acoustic output device 900 is 50 mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are both 5 mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 is fixed When the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 18mm, the frequency response curve (ie, curve L102) of the acoustic output device 900 is in the mid-to-high frequency range (for example, 200Hz-2000Hz ) is relatively smooth. Specifically, the curve L102 has small or no resonance peaks and/or resonance valleys in the mid-to-high frequency range. When the piezoelectric element 120 and the second piezoelectric element 140 are aligned along the length direction of the beam structure, When the distance is 14 mm or 22 mm, the frequency response curve of the acoustic output device 900 (ie, the curve L101 or L103) has a resonance peak and/or a resonance valley in the mid-to-high frequency range. As an exemplary illustration, as shown in Figure 10, the curve L101 has a resonance peak 1011 and a resonance valley 1012 within 200 Hz-2000 Hz, and the curve L103 has a resonance valley 1031 and a resonance peak 1032 within 200 Hz-2000 Hz. Therefore, through reasonable design The distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure (for example, 18 mm) can cause the resonance valley and resonance peak (for example, the resonance peak 1011) generated by the acoustic output device 900 in the mid-to-high frequency band. and the resonance valley 1012, the resonance valley 1031 and the resonance peak 1032) are combined (or called offset), so that the frequency response curve (for example, the curve L102) of the acoustic output device 900 is relatively flat, thereby ensuring that the acoustic output device 900 has better sound quality.

Figure 11 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

Figure 11 shows that when the length of the beam structure of the acoustic output device 900 is 50mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are both 5mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end is 5mm. , different frequency response curves of the acoustic output device 900 when there are different distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. Among them, curve L111, curve L112 and curve L113 are the frequency response curves of the acoustic output device 900 when the distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure are 12 mm, 14 mm and 18 mm respectively. The dotted circle M represents the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz).

It can be seen from FIG. 11 that when the length of the beam structure of the acoustic output device 900 is 50 mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 is 5 mm, and the piezoelectric element 120 or the second piezoelectric element 140 is distant from the fixed end 5mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 14mm, the frequency response curve (ie, curve L112) of the acoustic output device 900 is in the mid-to-high frequency range (for example, 200Hz-2000Hz) The curve in When the length is 10 mm or 18 mm, the frequency response curve of the acoustic output device 900 (ie, the curve L111 or L113) has a resonance peak and/or a resonance valley in the mid-to-high frequency range. As an illustration, as shown in Figure 11, curve L111 at 200 There is a resonance valley 1111 and a resonance peak 1112 within Hz-2000Hz, and the curve L113 has a resonance valley 1131 and a resonance peak 1132 within 200Hz-2000Hz. It can be concluded that by rationally designing the distance (for example, 14 mm) between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure, the resonance valley generated by the acoustic output device 900 in the mid-to-high frequency range can be achieved. and the resonance peaks (for example, the resonance valley 1111 and the resonance peak 1112, the resonance valley 1131 and the resonance peak 1132) are merged (or called canceled), so that the frequency response curve (for example, the curve L112) of the acoustic output device 900 is relatively flat, This ensures that the acoustic output device 900 has better sound quality.

Figure 12 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

Figure 12 shows that when the length of the beam structure of the acoustic output device 900 is 50mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are both 5mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end is 6mm. , corresponding to different frequency response curves of the acoustic output device 900 when there are different distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. Among them, curve L121, curve L122 and curve L123 are the frequency response curves of the acoustic output device 900 when the distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure are 10 mm, 12 mm and 14 mm respectively. The dotted circle N represents the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz).

It can be seen from FIG. 12 that when the length of the beam structure of the acoustic output device 900 is 50 mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 is 5 mm, and the piezoelectric element 120 or the second piezoelectric element 140 is distant from the fixed end 6mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 12mm, the frequency response curve (ie, curve L122) of the acoustic output device 900 is in the mid-to-high frequency range (for example, 200Hz-2000Hz) The curve in When 10mm or 14mm, the acoustic output The frequency response curve of the device 900 (ie, curve L121 or L123) has a resonance peak and/or a resonance valley in the mid-to-high frequency range. As an exemplary explanation, as shown in Figure 12, the curve L121 has a resonance valley 1211 and a resonance peak 1212 within 200 Hz-2000 Hz, and the curve L123 has a resonance valley 1231 and a resonance peak 1232 within 200 Hz-2000 Hz. It can be concluded that by rationally designing the distance (for example, 12 mm) between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure, the resonance valley generated by the acoustic output device 900 in the mid-to-high frequency range can be achieved. and the resonance peaks (for example, the resonance valley 1211 and the resonance peak 1212, the resonance valley 1231 and the resonance peak 1232) are merged (or called canceled), so that the frequency response curve (for example, the curve L122) of the acoustic output device 900 is relatively flat, This ensures that the acoustic output device 900 has better sound quality.

10-12, when the length of the beam structure, the length of the piezoelectric element 120 and the second piezoelectric element 140 remains unchanged, as the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 increases ( For example, Figures 10-12 are 4mm, 5mm, and 6mm respectively), the distance between the piezoelectric element 120 and the second piezoelectric element 140 corresponding to the combined resonance peak and resonance valley gradually decreases along the length direction of the beam structure (for example, Figure 10-12 are 18mm, 14mm, 12mm in order). Therefore, in some embodiments, the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 can be adjusted based on the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. distance. For example only, when the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 increases, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can be appropriately reduced, so that Merging the resonance peaks and resonance valleys makes the frequency response curve of the acoustic output device 900 relatively flat, thereby improving the sound quality of the acoustic output device 900 . For example, the ratio between the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 and the length of the beam structure is greater than 0.05, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 along the length direction of the beam structure The ratio to the length of the beam structure can be less than 0.5. For another example, the ratio between the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 and the length of the beam structure is greater than 0.1. The piezoelectric element 120 and the second piezoelectric element 140 are arranged along the length of the beam structure. The ratio between the upward distance and the length of the beam structure can be less than 0.3. For another example, the ratio between the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 and the length of the beam structure is greater than 0.12. The distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is greater than 0.12. The ratio between the distance and the length of the beam structure can be less than 0.25.

Figure 13 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

Figure 13 shows that when the length of the beam structure of the acoustic output device 900 (indicated by lb in the figure) is 37.5mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are both 5mm, the piezoelectric element 120 or the second piezoelectric element 140 When the electrical element 140 is 4 mm away from the fixed end, there are different frequency response curves of the acoustic output device 900 corresponding to different distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. The curve L131, the curve L132, and the curve L133 are respectively the frequency response curves of the acoustic output device 900 when the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 8 mm. The dotted circle O is the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz).

It can be seen from Figure 13 that when the length of the beam structure of the acoustic output device 900 is 37.5mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 is 5mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 is fixed When the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 9mm, the frequency response curve (ie, curve L132) of the acoustic output device 900 is in the mid-to-high frequency range (for example, 200Hz-2000Hz ) is relatively smooth. Specifically, the curve L132 has small or no resonance peaks and/or resonance valleys in the mid-to-high frequency range. When the piezoelectric element 120 and the second piezoelectric element 140 are aligned along the length of the beam structure, When the distance is 8 mm or 10 mm, the frequency response curve of the acoustic output device 900 (ie, the curve L131 or L133) has a resonance peak and/or a resonance valley in the mid-to-high frequency range. As an illustration, as shown in Figure 13, the curve L131 has a resonance valley 1311 and a resonance peak 1312 within 200 Hz-2000 Hz, and the curve L133 has a resonance valley 1331 and a resonance peak 1332 within 200 Hz-2000 Hz. From this it can be concluded that through Reasonable design of the distance (for example, 9 mm) between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can make the resonance valley and resonance peak (for example, resonance) generated by the acoustic output device 900 in the mid-to-high frequency range. The valley 1311 and the resonance peak 1312, the resonance valley 1331 and the resonance peak 1332) are combined (or called offset), so that the frequency response curve of the acoustic output device 900 is relatively flat, thereby ensuring that the acoustic output device 900 has better sound quality.

Figure 14 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

Figure 14 shows that when the length of the beam structure of the acoustic output device 900 is 37.5mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are both 5mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end is 5mm. When there are different distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure, the acoustic output device 900 has different frequency response curves. Among them, curve L141, curve L142 and curve L143 are the frequency response curves of the acoustic output device 900 when the distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure are 5.6mm, 6.2mm and 6.8mm respectively. . The dotted circle P is the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz).

It can be seen from Figure 14 that when the length of the beam structure of the acoustic output device 900 is 37.5mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 is 5mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 is fixed When the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 6.2mm, the frequency response curve (ie, curve L142) of the acoustic output device 900 is in the mid-to-high frequency band (for example, 200Hz- 2000Hz) is relatively smooth, specifically as curve L142 has small or no resonance peaks and/or resonance valleys in the mid-to-high frequency range, while when the piezoelectric element 120 and the second piezoelectric element 140 move along the length direction of the beam structure When the distance is 5.6 mm or 6.8 mm, the frequency response curve of the acoustic output device 900 (ie, the curve L141 or L143) has a resonance peak and/or a resonance valley in the mid-to-high frequency band. As an illustration, as shown in Figure 14, curve L141 has a resonance valley 1411 and a resonance peak 1412 within 200Hz-2000Hz, and the curve L143 has There are resonance valleys 1431 and resonance peaks 1432 within 200Hz-2000Hz. It can be concluded that by rationally designing the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure (for example, 6.2 mm), the resonance generated by the acoustic output device 900 in the mid-to-high frequency range can be achieved. The valleys and resonance peaks (for example, the resonance valley 1411 and the resonance peak 1412, the resonance valley 1431 and the resonance peak 1432) are merged (or called offset), so that the frequency response curve of the acoustic output device 900 is relatively flat, thereby ensuring that the acoustic output device 900 has better sound quality.

13 and 14, when the length of the beam structure, the length of the piezoelectric element 120 and the second piezoelectric element 140 remains unchanged, as the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 increases ( For example, Figures 13 and 14 are 4mm and 5mm respectively), the distance between the piezoelectric element 120 and the second piezoelectric element 140 corresponding to the merged resonance peak and resonance valley gradually decreases along the length direction of the beam structure (for example, Figures 13 and 14 14 is 9mm, 6.2mm). Therefore, in some embodiments, the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 can be adjusted based on the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. distance. For example only, when the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 increases, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can be appropriately reduced, so that Merging the resonance peaks and resonance valleys makes the frequency response curve of the acoustic output device 900 relatively flat, thereby improving the sound quality of the acoustic output device 900 . For example, the ratio between the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 and the length of the beam structure is greater than 0.1, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 along the length direction of the beam structure The ratio to the length of the beam structure can be less than 0.25. For another example, the ratio between the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 and the length of the beam structure is greater than 0.13. The distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is greater than 0.13. The ratio between the distance and the length of the beam structure can be less than 0.2.

Figure 15 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

Figure 15 shows that when the length of the beam structure of the acoustic output device 900 is 25mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are both 5mm, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end is 4mm. , corresponding to different frequency response curves of the acoustic output device 900 when there are different distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. Wherein, curve L151, curve L152 and curve L153 are respectively the frequency response curves of the acoustic output device 900 when the distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure are 0.5mm, 1.5mm and 2.5mm. . The dotted circle Q is the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz).

It can be seen from FIG. 15 that when the length of the beam structure of the acoustic output device 900 is 25 mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 is 5 mm, and the piezoelectric element 120 or the second piezoelectric element 140 is distant from the fixed end 4mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 1.5mm, the frequency response curve (ie, curve L152) of the acoustic output device 900 is in the mid-to-high frequency range (for example, 300Hz-3000Hz ) is relatively smooth. Specifically, the curve L152 has small or no resonance peaks and/or resonance valleys in the mid-to-high frequency range. When the piezoelectric element 120 and the second piezoelectric element 140 are aligned along the length of the beam structure, When the distance is 0.5 mm or 2.5 mm, the frequency response curve of the acoustic output device 900 (ie, the curve L151 or L153) has a resonance peak and/or a resonance valley in the mid-to-high frequency range. As an illustration, as shown in FIG. 15 , curve L151 has a resonance valley 1511 and a resonance peak 1512 within 300Hz-3000Hz, and curve L153 has a resonance valley 1531 and a resonance peak 1532 within 300Hz-3000Hz. It can be concluded that by rationally designing the distance (for example, 1.5 mm) between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure, the resonance generated by the acoustic output device 900 in the mid-to-high frequency range can be achieved. The valleys and resonance peaks (for example, the resonance valley 1511 and the resonance peak 1512, the resonance valley 1531 and the resonance peak 1532) are merged (or called offset), so that the frequency response curve of the acoustic output device 900 is relatively flat, thereby ensuring that the acoustic output device 900 has better sound quality.

10, 13 and 15, when the lengths of the piezoelectric element 120 and the second piezoelectric element 140, and the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 remain unchanged, as the length of the beam structure Reducing (for example, Figures 10, 13 and 15 are 50mm, 37.5mm, and 25mm respectively), the distance between the piezoelectric element 120 corresponding to the merged resonance peak and the resonance valley and the second piezoelectric element 140 along the length direction of the beam structure gradually increases. decrease (for example, Figures 10, 13, and 15 are 18mm, 9mm, and 1.5mm respectively). Therefore, in some embodiments, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can be adjusted based on the lengths of different beam structures. For example only, when the length of the beam structure is reduced, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can be appropriately reduced, thereby merging the resonant peaks and resonant valleys, so that the acoustic output device 900 The frequency response curve is relatively flat, which improves the sound quality of the acoustic output device 900 . For example, the ratio between the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure and the length of the beam structure may be less than 0.6. For another example, the ratio between the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure and the length of the beam structure may be less than 0.4. For another example, the ratio between the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure and the length of the beam structure may be less than 0.2. For another example, the ratio between the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure and the length of the beam structure may be less than 0.1.

Figure 16 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

Figure 16 shows that when the length of the beam structure of the acoustic output device 900 is 50mm, the lengths of the piezoelectric element 120 and the second piezoelectric element 140 (indicated by lp in the figure) are both 25mm, the piezoelectric element 120 or the second piezoelectric element 140 is When the element 140 is 4 mm away from the fixed end, there are different frequency response curves of the acoustic output device 900 corresponding to different distances between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure. Among them, curve L161, curve L162 and curve L163 are respectively when the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is -4mm, -2.5mm and -1mm. Frequency response curve of the acoustic output device 900. Inside the dotted circle R is the first resonance peak generated by the vibrating element 110 and the mass element 130 in the low frequency band (for example, 50 Hz-2000 Hz). The distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure may refer to the distance between the center point (eg, centroid) of the piezoelectric element 120 and the center point of the second piezoelectric element 140 distance. It should be noted that when the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is 0, it can be understood that the center point of the piezoelectric element 120 and the center point of the second piezoelectric element 140 are along the The projections of the vibration directions of the beam structure coincide. When the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is a positive number, it can be understood that the position of one of the piezoelectric elements (for example, the second piezoelectric element 140) does not change, and the position of the other piezoelectric element does not change. The distance between the center points of the piezoelectric element 120 and the second piezoelectric element 140 when the image mass element 130 is deflected along the length of the beam structure (for example, the piezoelectric element 120 ). When the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is a negative number, it can be understood that the position of one of the piezoelectric elements (for example, the second piezoelectric element 140) does not change, and the position of the other piezoelectric element does not change. The distance between the center points of the piezoelectric element 120 and the second piezoelectric element 140 when the fixed end 111 is deflected along the length direction of the beam structure (for example, the piezoelectric element 120 ).

It can be seen from Figure 16 that when the length of the beam structure of the acoustic output device 900 is 50mm, the length of the piezoelectric element 120 and the second piezoelectric element 140 is 25mm, and the piezoelectric element 120 or the second piezoelectric element 140 is far from the fixed end 4mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is -2.5mm, the frequency response curve (ie, curve L162) of the acoustic output device 900 is in the mid-to-high frequency band (for example, 300Hz- 3000Hz) is relatively smooth, specifically as curve L162 has small or no resonance peaks and/or resonance valleys in the mid-to-high frequency range, while when the piezoelectric element 120 and the second piezoelectric element 140 move along the length direction of the beam structure When the distance is -4 mm or -1 mm, the frequency response curve (ie, curve L161 or L163) of the acoustic output device 900 has a resonance peak and/or a resonance valley in the mid-to-high frequency range. As an illustration, as shown in Figure 16, curve L161 has a resonance valley 1611 and a resonance peak 1612 within 300Hz-3000Hz, and the curve L163 has a resonance valley 1611 and a resonance peak 1612 within 300Hz-3000Hz. There are resonance valleys 1631 and resonance peaks 1632 within 3000Hz. It can be concluded that by rationally designing the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure (for example, -2.5 mm), the acoustic output device 900 can produce sound in the mid-to-high frequency range. The resonance valley and the resonance peak (for example, the resonance valley 1611 and the resonance peak 1612, the resonance valley 1631 and the resonance peak 1632) are combined (or called offset), so that the frequency response curve of the acoustic output device 900 is relatively flat, thereby ensuring the acoustic output Device 900 has better sound quality.

10 and 16, when the length of the beam structure, the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end 111 remains unchanged, as the length of the piezoelectric element 120 and the second piezoelectric element 140 increases ( For example, Figures 10 and 16 are 5mm and 25mm respectively), the distance between the piezoelectric element 120 and the second piezoelectric element 140 corresponding to the combined resonance peak and resonance valley gradually decreases along the length direction of the beam structure (for example, Figures 10 and 16 16 is 18mm, -2.5mm). Therefore, in some embodiments, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can be adjusted based on the lengths of the different piezoelectric elements 120 and the second piezoelectric element 140 . For example only, when the lengths of the piezoelectric element 120 and the second piezoelectric element 140 are increased, the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure can be appropriately reduced, thereby harmonizing the resonance peak. The vibration valleys are merged so that the frequency response curve of the acoustic output device 900 is relatively flat, thereby improving the sound quality of the acoustic output device 900 . For example, the ratio between the lengths of the piezoelectric element 120 and the second piezoelectric element 140 and the length of the beam structure is greater than 0.05, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is less than the length of the beam structure. The ratio between lengths can be less than 0.4. For another example, the ratio between the lengths of the piezoelectric element 120 and the second piezoelectric element 140 and the length of the beam structure is greater than 0.1, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is less than the length of the beam structure. The ratio between the lengths can be less than 0.3. For another example, the ratio between the lengths of the piezoelectric element 120 and the second piezoelectric element 140 and the length of the beam structure is greater than 0.4, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 along the length direction of the beam structure is less than the length of the beam structure. The ratio between the lengths may be less than 0 (that is, there is an overlapping area between the piezoelectric element 120 and the second piezoelectric element 140 on the length of the beam structure).

10-16, by rationally designing the distance between the piezoelectric element 120 and the second piezoelectric element 140, the frequency response curve of the acoustic output device 900 (for example, curves L102, L112, L122, L132, L142, L152 and L162) are relatively smooth in the mid-to-high frequency band, so that the acoustic output device 900 can have better sound quality. In some embodiments, the length of the beam structure may be less than 50 mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 may be less than 25 mm. In some embodiments, the length of the beam structure may be less than 50 mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 may be less than 18 mm. In some embodiments, the length of the beam structure may be less than 40 mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 may be less than 10 mm. In some embodiments, the length of the beam structure may be less than 40 mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 may be less than 2.5 mm. In some embodiments, the length of the beam structure may be less than 30 mm, and the distance between the piezoelectric element 120 and the second piezoelectric element 140 may be less than -1 mm.

Combining the curve L101, the curve L112 and the curve L123, it can be seen that when the length of the beam structure, the length of the piezoelectric element 120 and the distance between the piezoelectric element 120 and the second piezoelectric element 140 are constant, the piezoelectric element 120 or the second piezoelectric element 140 will When the distance between the electrical element 140 and the fixed end (for example, the distance between the second piezoelectric element 140 and the fixed end shown in FIG. 9 ) increases, the peak value of the first resonance peak generated by the acoustic output device 900 in the low frequency band is at increase. As an example, the peak value of the first resonance peak of the curve L101 in the dotted circle Z is around 170dB, the peak value of the first resonance peak of the curve 112 in the dotted circle M is around 175dB, and the peak value of the first resonance peak of the curve L123 in the dotted circle N is around 175dB. The peak value of a resonance peak is around 180dB. In some embodiments, the first resonance peak-to-peak value of the acoustic output device 900 in the low frequency band can be increased by increasing the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end, thereby improving the acoustic output device 900 Sensitivity in the low frequency band. In some embodiments, the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end may be greater than 3 mm. In some embodiments, the piezoelectric element 120 or the second piezoelectric element 140 The distance from the fixed end can be greater than 5mm. In some embodiments, the distance between the piezoelectric element 120 or the second piezoelectric element 140 and the fixed end may be greater than 7 mm.

Figure 17 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification.

As shown in FIG. 17 , the structure of the acoustic output device 1700 can be regarded as a change based on the structure of the acoustic output device 200 . Specifically, the difference between the acoustic output device 1700 and the acoustic output device 200 is that the acoustic output device 1700 may also include a second vibration element 160 , and the vibration element 110 and the second vibration element 160 are symmetrically arranged on both sides of the mass element 130 . The acoustic output device 1700 may include a third piezoelectric element 170 connected (or attached) to the second vibration element 160 . The third piezoelectric element 170 and the piezoelectric element 120 are symmetrically arranged on both sides of the mass element 130 . In some embodiments, the piezoelectric element 120 and the third piezoelectric element 170 are respectively disposed on two piezoelectric beams located on both sides of the mass element 130, and the electrical signals input by the piezoelectric element 120 and the third piezoelectric element 170 They may be the same and can be regarded as the piezoelectric element 120 and the third piezoelectric element 170 being connected in parallel. In some embodiments, the second vibration element 160 vibrates in the same direction as the vibration element 110 . In some embodiments, the piezoelectric element 120 and the third piezoelectric element 170 can be in the d31 working mode, and the deformation directions of the piezoelectric element 120 and the third piezoelectric element 170 can be consistent with the directions of the vibration element 110 and the second vibration element 160 . The vibration direction is vertical. In some embodiments, the piezoelectric element 120 and the third piezoelectric element 170 may be in the working mode of d33, and the deformation direction of the piezoelectric element 120 and the third piezoelectric element 170 may be parallel to the vibration direction of the vibration element 110 . In some embodiments, one end of the vibrating element 110 and the second vibrating element 160 away from the mass element 130 is fixedly arranged (ie, the fixed end). For example, one end of the vibrating element 110 and the second vibrating element 160 away from the mass element 130 can be fixed on other components of the acoustic output device 1700 (eg, the housing). For another example, the piezoelectric element 120 and the third piezoelectric element 170 can be in the working mode of d33, with one end of the piezoelectric element 120 and the third piezoelectric element 170 fixed along the vibration direction of the vibrating element 110 and the second vibrating element 160, and the other end. One end is respectively attached to the vibrating element 110 and the second vibrating element 160 away from the mass element 130 One end of the vibrating element 110 and the second vibrating element 160 away from the mass element 130 can be fixedly arranged relative to the mass element 130 . For more descriptions about the second vibration element 160 and the third piezoelectric element 170, please refer to the relevant descriptions of the vibration element 110 and the piezoelectric element 120 respectively, which will not be described again here.

Figure 18 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In FIG. 18 , curve L181 is the frequency response curve when a massless element is connected between the vibrating element 110 and the second vibrating element 160 (or the vibrating element 110 and the second vibrating element 160 are unloaded). Curve L182 is a frequency response curve when a mass element (or load of the vibrating element 110 and the second vibrating element 160 ) is connected between the vibrating element 110 and the second vibrating element 160 .

As shown in Figure 18, the curves between adjacent resonance peaks on curve L181 and curve L182 are relatively smooth, and there is no resonance valley. It can be concluded that by arranging a structure in which piezoelectric sheets are connected in parallel, the frequency response curve of the acoustic output device 1700 will not produce a resonance valley, making the frequency response curve smoother and conducive to improving the sound quality of the acoustic output device 1700 . In addition, by comparing the resonant peak 1811 of the curve L181 and the resonant peak 1821 of the curve L182, it can be found that when the mass element 130 is connected between the vibrating element 110 and the second vibrating element 160, the resonant frequency corresponding to the resonant peak will decrease. . Therefore, the resonant frequency corresponding to the resonant peak generated by the acoustic output device 1700 in the low frequency band (eg, 100 Hz-1000 Hz) can be changed by changing the mass of the mass element 130 .

Figure 19 is a schematic structural diagram of an acoustic output device according to some embodiments of this specification.

As shown in FIG. 19 , the structure of the acoustic output device 1900 can be regarded as a change based on the structure of the acoustic output device 200 . Specifically, the difference between the acoustic output device 1900 and the acoustic output device 200 is that the acoustic output device 1900 may also include a third vibration element 180 , and the third vibration element 180 is connected to the mass element 130 . The vibration direction of the third vibration element 180 is parallel to the vibration direction of the vibration element 110 . Further, the acoustic output device 1900 may also include a fourth piezoelectric element 190 , and the fourth piezoelectric element 190 may be connected to the third vibration element 180 . In some embodiments, the fourth piezoelectric element 190 is in the d31 working mode, and the deformation direction of the fourth piezoelectric element 190 is perpendicular to the vibration direction of the third vibration element 180 . In some embodiments, the third vibration element 180 and the vibration element 110 may have the same or different structures, materials, etc. In some embodiments, the fourth piezoelectric element 190 and the piezoelectric element 120 may have the same or different structures, materials, etc. In some embodiments, as shown in FIG. 19 , the beam structure of the third vibration element 180 located on both sides of the mass element 130 can be arranged symmetrically. In some embodiments, the fourth piezoelectric element 190 may include two piezoelectric sheets located on both sides of the mass element 130 . In some embodiments, the fourth piezoelectric element 190 may include a piezoelectric sheet, and the piezoelectric sheet may completely cover the third vibration element 180 or partially cover the third vibration element 180 . For more descriptions about the third vibration element 180 and the fourth piezoelectric element 190, please refer to the relevant descriptions of the vibration element 110 and the piezoelectric element 120 respectively, which will not be described again here.

It should be noted that the acoustic output device 1900 shown in FIG. 19 is only used for illustrative purposes and is not intended to limit the scope of protection of this specification. For those of ordinary skill in the art, various changes and modifications can be made based on the guidance of this specification. For example, the fourth piezoelectric element 190 may include a piezoelectric sheet, and the piezoelectric sheet may completely cover the third vibration element 180 or partially cover the third vibration element 180 . For another example, the piezoelectric element 120 may include a piezoelectric sheet, and the piezoelectric sheet may completely cover the vibrating element 110 .

In some embodiments, vibrating element 110 may have a cantilever beam structure. The cantilever beam has a fixed end 111 and a free end 112 . The mass element 130 is connected to the vibration element 110 at its free end 112 . In some embodiments, the third vibration element 180 may have a beam structure. For example, the third vibration element 180 may be a free beam, at least a part of the free beam (for example, a central region in the length direction) is connected to the mass element 130 , and both ends of the free beam are free ends. In some embodiments, on the projection plane along the vibration direction of the third vibration element 180 or the vibration element 110, the length direction of the third vibration element 180 (i.e. The angle between the long axis direction of the free beam and the length direction of the vibrating element 110 may be 90°. In some embodiments, the connection position between the mass element 130 and the third vibration element 180 can be located at the center of the length direction of the third vibration element 180 , that is, the vibration element 110 and the third vibration element 180 can form a "T"-shaped structure (or called a T-beam). In some embodiments, the angle between the length direction of the third vibration element 180 and the length direction of the vibration element 110 may also be less than 90° or greater than 90°. In some embodiments, the connection position between the mass element 130 and the third vibration element 180 can be located at any position along the length direction of the third vibration element 180 .

In some embodiments, the vibration element 110 and the third vibration element 180 may be an integrally formed “T”-shaped structure or other configurations. Other configurations include that different positions of the vibrating element 110 have different widths (ie, the y direction in the figure) along the length direction of the vibrating element 110 (i.e., the x direction in the figure). For example, the width is larger closer to the free end, or the width is larger. The width becomes smaller near the free end, etc.

Figure 20 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In FIG. 20 , curve L201 is the frequency response curve generated when the piezoelectric element 120 is excited alone (that is, the frequency response curve generated when the vibrating element 110 (or cantilever beam) drives the mass element 130 to vibrate). Curve L202 is the frequency response curve generated when the fourth piezoelectric element 190 is excited alone (that is, the frequency response curve generated when the third vibrating element 180 (also known as the free beam) and the mass element 130 vibrate). Curve L203 is the frequency response curve when the piezoelectric element 120 and the fourth piezoelectric element 190 in the acoustic output device 1900 are excited at the same time (that is, the vibrating element 110, the third vibrating element 180 and the mass element 130 are simultaneously excited (or called a T-beam) Frequency response curve produced during vibration).

As shown in FIG. 20 , curve L201 has at least two resonance peaks (eg, a first resonance peak 2011 and a second resonance peak 2012) within the audible range of the human ear (eg, 20 Hz-20000 Hz). There is a resonance valley 2013 between the first resonance peak 2011 and the second resonance peak 2012. In some embodiments, the frequency of the first resonance peak 2011 may be at 50 Hz-2000Hz range. The frequency of resonance valley 2013 is around 1330Hz. Curve L202 has at least one resonance peak (eg, resonance peak 2021) within the audible range of the human ear (eg, 20 Hz-20000 Hz). Among them, the frequency of resonance peak 2021 is around 1330Hz. Curve L203 has at least two resonance peaks (eg, first resonance peak 2031 and second resonance peak 2032) within the audible range of the human ear (eg, 20 Hz-20000 Hz). As can be seen from FIG. 20 , the curve L203 does not have a resonance valley between the first resonance peak 2031 and the second resonance peak 2032 . This is because the resonance peak 2021 complements the resonance valley 2013 with the same frequency, so that the curve L203 does not have a resonance valley between the first resonance peak 2031 and the second resonance peak 2032 . In addition, in the frequency range greater than 100 Hz, the amplitude of curve L203 is improved compared to curve L201.

Therefore, in some embodiments, the resonance peak generated by the vibration of the third vibration element 180 and the mass element 130 in the low frequency band (for example, 50Hz-2000Hz) (for convenience of description, hereafter referred to as the resonance peak corresponding to the third vibration element 180 ) can be resonance peak) to supplement the resonance valley between the first resonance peak and the second resonance peak produced by the vibration of the vibration element 110 and the mass element 130 (for convenience of description, hereafter referred to as the resonance valley corresponding to the vibration element 110), thereby making the acoustic output The frequency response curve of the device 1900 does not have a resonance valley between the first resonance peak and the second resonance peak, thereby making the curve between the first resonance peak and the second resonance peak smoother, which is beneficial to improving the sound quality of the acoustic output device.

In some embodiments, the ratio between the frequency f ₀ of the first resonance peak and the frequency f ₁ of the second resonance peak corresponding to the vibration element 110 may be in the range of 5-30. In some embodiments, the ratio between the frequency f ₀ of the first resonance peak and the frequency f ₁ of the second resonance peak corresponding to the vibration element 110 may be in the range of 8-20. In some embodiments, the ratio between the frequency f ₀ of the first resonance peak and the frequency f ₁ of the second resonance peak corresponding to the vibration element 110 may be in the range of 10-18.

In some embodiments, the resonant frequency of the beam structure (for example, the cantilever beam corresponding to the vibrating element 110 or the free beam corresponding to the third vibrating element 180) can be determined according to formula (2):

Among them, l represents the length of the beam structure, EI represents the bending stiffness of the beam structure, ρ _l represents the density per unit length of the beam structure, and β _i l represents the coefficient related to the i -th order resonance eigenvalue. According to formula (2), when the bending stiffness EI and ρ _l of the beam structure are fixed, the resonant frequency of the beam structure changes with the change of β _i l .

In some embodiments, the frequency equation of the vibration element 110 (cantilever beam) connected to the mass element 130 can be expressed as:

cos( β _i l ₁ )． cosh( β _i l ₁ )+1= α . β _i l ₁ ． (sin( β _i l ₁ ). cosh( β _i l ₁ )-cos( β _i l ₁ ). sinh( β _i l ₁ )), (3)

Wherein, α represents the ratio between the mass of the mass element 130 and the mass of the vibration element 110, and β _i l ₁ represents the coefficient related to the i-th order resonance eigenvalue corresponding to the cantilever beam. Solving formula (3), we can get the value of β _i l ₁ as shown in Table 1 below:

In some embodiments, the frequency equation of the third vibration element 180 (free beam) can be expressed as:

cos ( β _i l ₂ ) cosh ( β _i l ₂ )-1=0, (4)

Among them, β _i l ₂ represents the coefficient related to the i-th order resonance eigenvalue corresponding to the free beam. Solving formula (4), we can get the values of β _i l ₂ to be 4.730, 7.853...(i=1, 2...).

與振動元件110對應的第二諧振峰對應的頻率f ₁之間的比值可以小於2。在一些實施例中，第三振動元件180對應的諧振峰的頻率

與振動元件110對應的第二諧振峰的頻率f ₁之間的比值可以小於1.5。在一些實施例中，第三振動元件180對應的諧振峰的頻率

與振動元件110對應的第二諧振峰的頻率f ₁之間的比值可以小於1。在一些實施例中，第三振動元件180對應的諧振峰的頻率

與振動元件110對應的第二諧振峰的頻率f ₁之間的比值可以小於0.5。在一些實施例中，為了保證第三振動元件180對應的諧振峰能夠補充振動元件110對應的諧振谷，第三振動元件180對應的諧振峰的頻率

可以位於振動元件110對應的諧振谷的頻率附近(例如，諧振谷2013與諧振峰2021對應的諧振頻率均在1330Hz左右)，由此，第三振動元件180對應的諧振峰的頻率

可以小於振動元件110對應的第二諧振峰對應的諧振頻率f ₁，即 In order to ensure that the resonance peak corresponding to the third vibration element 180 can supplement the resonance valley corresponding to the vibration element 110, in some embodiments, the frequency of the resonance peak corresponding to the third vibration element 180

The ratio between the frequencies f ₁ corresponding to the second resonance peak corresponding to the vibration element 110 may be less than 2. In some embodiments, the frequency of the resonance peak corresponding to the third vibration element 180

The ratio between the frequencies f ₁ of the second resonance peak corresponding to the vibration element 110 may be less than 1.5. In some embodiments, the frequency of the resonance peak corresponding to the third vibration element 180

The ratio between the frequencies f ₁ of the second resonance peak corresponding to the vibration element 110 may be less than 1. In some embodiments, the frequency of the resonance peak corresponding to the third vibration element 180

The ratio between the frequencies f ₁ of the second resonance peak corresponding to the vibration element 110 may be less than 0.5. In some embodiments, in order to ensure that the resonance peak corresponding to the third vibration element 180 can supplement the resonance valley corresponding to the vibration element 110, the frequency of the resonance peak corresponding to the third vibration element 180 is

It can be located near the frequency of the resonance valley corresponding to the vibration element 110 (for example, the resonance frequencies corresponding to the resonance valley 2013 and the resonance peak 2021 are both around 1330 Hz). Therefore, the frequency of the resonance peak corresponding to the third vibration element 180

It may be less than the resonant frequency f ₁ corresponding to the second resonant peak corresponding to the vibrating element 110, that is,

Among them, the value of β ₁ l ₂ is 4.730, and formula (5) can be expressed as:

According to formula (6) and Table 1, in some embodiments, the ratio between the length of the third vibration element 180 and the length of the vibration element 120 may be greater than 0.7. In some embodiments, the ratio between the length of the third vibration element 180 and the length of the vibration element 120 Value can be greater than 1. In some embodiments, the ratio between the length of the third vibration element 180 and the length of the vibration element 120 may be greater than 1.2.

In addition, combining curves L201 and L203, it can be seen that in the medium and high frequency band (200Hz-20000Hz), the amplitude of curve L203 is greater than the amplitude of curve L201. Thus, in some embodiments, the third vibration element 180 can increase the vibration amplitude of the mass element 130 in a range greater than 100 Hz. Therefore, by adopting the same or similar structure of the acoustic output device 1900, the acoustic output device can have better sensitivity in the mid-to-high frequency band.

Figure 21 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In FIG. 21 , curve L211 is the frequency response curve when the piezoelectric element 120 is excited alone (that is, the frequency response curve generated when the vibration element 110 (or cantilever beam) drives the mass element 130 to vibrate). Curve L212 is the frequency response curve when the fourth piezoelectric element 190 is excited alone (that is, the frequency response curve generated when the third vibration element 180 (also known as the free beam) and the mass element 130 vibrate). Curve L213, curve L214, curve L215 and curve L216 are respectively when the piezoelectric element 120 and the fourth piezoelectric element 190 in the acoustic output device 1900 are excited at the same time, the phase difference of the excitation signal (represented by theta in the figure) is 0° and 45 Frequency response curves at °, 135° and 180°.

Combining the curve L213, the curve L214, the curve L215 and the curve L216, it can be seen that when the phase difference between the excitation signals of the piezoelectric element 120 and the fourth piezoelectric element 190 in the acoustic output device 1900 exceeds 135°, the frequency response curve of the acoustic output device 1900 A resonance valley (for example, the resonance valley 2161 in the curve L216) may appear between the first resonance peak and the second resonance peak, which is caused by the vibrations of the vibration element 110 and the third vibration element 180 being out of phase and canceling each other. Therefore, in order to ensure that the frequency response curve of the acoustic output device 1900 does not have a resonance valley between the first resonance peak and the second resonance peak, and has a larger flat curve range, thereby having better sound quality, in some embodiments , the phase difference between the excitation signals of the piezoelectric element 120 and the fourth piezoelectric element 190 may be less than or equal to 135°. In some embodiments, The phase difference between the excitation signals of the piezoelectric element 120 and the fourth piezoelectric element 190 may be less than or equal to 60°. In some embodiments, the phase difference between the excitation signals of the piezoelectric element 120 and the fourth piezoelectric element 190 may be less than or equal to 30°. In some embodiments, the phase difference between the excitation signals of the piezoelectric element 120 and the fourth piezoelectric element 190 may be 0°.

Figure 22 is a frequency response graph of an acoustic output device according to some embodiments of the present specification.

In Figure 22, curve L221, curve L222, curve L223, curve L224 and curve L225 respectively represent the length of the third vibration element 180 of the acoustic output device 1900 (represented by lp_d2 in the figure), which is 0 mm (that is, it can be regarded as the acoustic output device 1900 Excluding the third vibrating element 180, it is equivalent to the frequency response curve at 20 mm, 22 mm, 24 mm and 30 mm of the acoustic output device 200). Among them, the length of the vibrating elements 110 (indicated by lp_d in the figure) is 20 mm. Combining the curve L221, the curve L222, the curve L223, the curve L224 and the curve L225, it can be seen that when the length of the third vibration element 180 is less than 24mm, the curve L221, the curve L222 and the curve L223 all have resonance valleys near 2250Hz, and the third vibration element 180 The increase in length can only increase the amplitude of the frequency response curve of the acoustic output device 1900 in the mid-to-high frequency band (for example, 2000Hz-20000Hz), that is, the sensitivity of the acoustic output device 1900 in the mid-to-high frequency range is increased. When the length of the third vibrating element 180 exceeds 24 mm, there is no resonance valley between the first resonance peak and the second resonance peak on the curve L224 and the curve L225, which makes the frequency response curve of the acoustic output device 1900 flatter, which is advantageous. To improve sound quality. In addition, combining the curve L224 and the curve L225, it can be seen that as the length of the third vibrating element 180 increases, the amplitude of the frequency response curve also increases, which is beneficial to improving the sensitivity of the acoustic output device 1900. In addition, as the length of the third vibrating element 180 increases, the resonance peak of the frequency response curve of the acoustic output device 1900 in the mid-to-high frequency range (eg, 2000 Hz-20000 Hz) shifts to the left (that is, moves to low frequency). Therefore, the length of the third vibration element 180 can be adjusted to meet the vibration performance requirements of the acoustic output device 1900 .

It can be seen from the above that in the acoustic output device 1900, the sensitivity and sound quality of the acoustic output device 1900 can be improved by increasing the length of the third vibrating element 180. In some embodiments, the length of the vibration element 110 may be 20 mm, and the length of the third vibration element 180 may be greater than 24 mm. In some embodiments, the length of the third vibrating element 180 may be greater than 26 mm.

Possible beneficial effects brought about by the embodiments of this specification include but are not limited to: (1) In the acoustic output device provided by the embodiments of this specification, the vibration of the mass element and vibration can make its frequency response curve in the low frequency band (for example, 50Hz~ 2000Hz) has a first resonance peak, thereby improving the sensitivity of the acoustic output device in the low frequency band, and has a second resonance peak in the high frequency band (for example, 2000Hz~20000Hz), and the first resonance peak and the second resonance There is at least one resonance valley between the peaks, and the amplitude difference between the first resonance peak or the second resonance peak and the at least one resonance valley is less than 80dB, thereby obtaining a relatively flat vibration response curve from low frequency to high frequency, and then Improve the sound quality of the acoustic output device; (2) By adjusting the spacing between the piezoelectric element and the second piezoelectric element in the length direction of the beam structure, the resonance peaks and resonance valleys generated by the acoustic output device in the mid-to-high frequency range can be merged, This can eliminate the high-order modes of the acoustic output device in the mid-to-high frequency range, making the frequency response curve smoother and ensuring that the sound quality of the acoustic output device can be improved; (3) By making the second mass element have a greater mass than the first mass element The mass can make the beam structure tend to be fixed on one side of the second mass element, thereby solving the problem that the fixed end of the beam structure is difficult to find a fixed boundary and difficult to fix in the acoustic output device (for example, a shell), and by adjusting the second mass element The ratio between the masses of the second mass element and the first mass element can realize the adjustment of the resonant frequency corresponding to the first resonance peak; (4) The deformation direction of the piezoelectric element is parallel to the vibration direction of the vibrating element. By adjusting the first position The ratio between the distance to the fixed end of the beam structure and the length of the beam structure can adjust the resonant frequency corresponding to the resonance peak of the acoustic output device in the low frequency band, so that the sensitivity of the acoustic output device can be improved in different frequency bands. Applicable to more usage scenarios; (5) By arranging the third piezoelectric element and the piezoelectric element symmetrically on both sides of the mass element, the frequency response curve of the acoustic output device can be reduced or eliminated The resonance valley within the audible range of the human ear ensures that the frequency response curve of the acoustic output device is relatively smooth and has better sound quality; (6) The fourth piezoelectric element is connected to the third vibration element, and the fourth piezoelectric element The deformation direction is perpendicular to the vibration direction of the third vibrating element, which can make the frequency response curve of the acoustic output device smoother and have better sound quality, and the third vibrating element can increase the vibration amplitude of the mass element in the low frequency band, thereby improving the acoustic output The sensitivity of the device in the low frequency band.

It should be noted that different embodiments may produce different beneficial effects. In different embodiments, the possible beneficial effects may be any one or a combination of the above, or any other possible beneficial effects.

The basic concepts have been described above. It is obvious to those skilled in the art that the above detailed disclosure is only an example and does not constitute a limitation of this specification. Although not explicitly stated herein, various modifications, improvements, and corrections may be made to this specification by those skilled in the art. Such modifications, improvements, and corrections are suggested in this specification, and therefore such modifications, improvements, and corrections remain within the spirit and scope of the exemplary embodiments of this specification.

At the same time, this specification uses specific words to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and/or "some embodiments" means a certain feature, structure, or characteristic related to at least one embodiment of this specification. Therefore, it should be emphasized and noted that “one embodiment” or “an embodiment” or “an alternative embodiment” mentioned twice or more at different places in this specification does not necessarily refer to the same embodiment. . In addition, certain features, structures or characteristics in one or more embodiments of this specification may be appropriately combined.

Similarly, it should be noted that, in order to simplify the expression disclosed in this specification and thereby help understand one or more embodiments of the invention, in the previous description of the embodiments of this specification, multiple features are sometimes combined into one embodiment. in a diagram or its description. However, this method of disclosure does not mean that the object of the description requires more features than are mentioned in the claim. In fact, embodiments may have less than all features of a single disclosed embodiment.

In some embodiments, digits are used to describe the quantities of components and properties. It should be understood that the modifiers "about", "approximately" or "substantially" are used in some examples to describe such numbers. Grooming. Unless otherwise stated, "about", "approximately" or "substantially" means that the number is allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximations that may vary depending on the desired characteristics of individual embodiments. In some embodiments, numerical parameters should account for the specified number of significant digits and use general digit preservation methods. Although the numerical ranges and parameters used to identify the breadth of ranges in some embodiments of this specification are approximations, in specific embodiments, such numerical values are set as accurately as is feasible.

Finally, it should be understood that the embodiments in this specification are only used to illustrate the principles of the embodiments in this specification. Other variations may also fall within the scope of this specification. Accordingly, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to those expressly introduced and described in this specification.

100:Acoustic output device

110:Vibration element

120: Piezoelectric element

130:Quality component

140: Second piezoelectric element

150: Second mass element

160: Second vibration element

170: The third piezoelectric element

180: The third vibration element

190: The fourth piezoelectric element

210: Shell structure

220: Fixed structure

Claims (11)

An acoustic output device comprising: a vibrating element having a beam structure extending along the length; The piezoelectric element is used to deform in response to an electrical signal, and the deformation drives the vibrating element to vibrate. The piezoelectric element is attached to the first position of the beam structure, and the size of the attached area along the length direction is not the same. Exceeds 80% of the dimension of the beam structure along that length; and A mass element connected to a second position of the beam structure, wherein the first position and the second position are spaced apart in the length direction, and the vibration of the vibrating element drives the mass element in a direction perpendicular to the length direction. vibrates in the direction. The acoustic output device of claim 1, wherein the vibration element resonates with the mass element to generate a first resonance peak, and the frequency range of the first resonance peak is 50Hz-2000Hz. The acoustic output device of claim 2, wherein the vibrations of the vibration element and the mass element have a second resonance peak, and the ratio of the frequency of the second resonance peak to the frequency of the first resonance peak is greater than 5. The acoustic output device of claim 3, wherein the vibration of the vibration element and the mass element generates at least one resonance valley between the first resonance peak and the second resonance peak, wherein the first resonance peak or the second resonance peak The amplitude difference between the second resonance peak and the at least one resonance valley is less than 80 dB. The acoustic output device of claim 1, wherein the deformation direction of the piezoelectric element is perpendicular to the vibration direction of the vibrating element. The acoustic output device of claim 5, further comprising a second piezoelectric element attached to a third position of the beam structure, wherein the piezoelectric element and the second piezoelectric element They are spaced apart in the length direction of the vibrating element. The acoustic output device of claim 5, further comprising a second A mass element, wherein the mass element and the second mass element are respectively located on both sides of the piezoelectric element in the length direction of the vibrating element, wherein the mass of the second mass element is greater than the mass of the mass element. The acoustic output device of claim 1, wherein the deformation direction of the piezoelectric element is parallel to the vibration direction of the vibration element; one end of the piezoelectric element is fixed along the vibration direction, and the other end is connected to the beam structure at the first position Connection; the beam structure includes a fixed end, and the ratio between the distance between the first position and the fixed end and the length of the beam structure is less than 0.6. The acoustic output device of claim 1, further comprising a second vibrating element and a third piezoelectric element connected to the second vibrating element; wherein the vibrating element and the second vibrating element are on both sides of the mass element. The third piezoelectric element and the piezoelectric element are arranged symmetrically on both sides of the mass element. The acoustic output device of claim 1, further comprising a third vibration element connected to the mass element; wherein the vibration direction of the third vibration element is parallel to the vibration direction of the vibration element; in In a frequency range greater than 100 Hz, the third vibration element increases the vibration amplitude of the mass element. The acoustic output device of claim 10, further comprising a fourth piezoelectric element connected to the third vibration element, wherein the deformation direction of the fourth piezoelectric element is consistent with the third vibration element. The vibration direction of the element is vertical; the electrical signals received by the piezoelectric element and the fourth piezoelectric element have a phase difference, and the phase difference is less than 135°.

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