Energy conversion device, speaker and sound output device

Abstract

The present specification relates to an energy conversion device, a speaker, and an audio output device, the energy conversion device including a magnetic circuit system including a magnet assembly and a magnetic flux conducting cover installed to at least partially surround the magnet assembly, and a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet distributed respectively on both sides of the magnet assembly along the vibration direction of the magnet assembly and elastically supporting the magnet assembly within the magnetic flux conducting cover, the energy conversion device having a resonant peak frequency of less than 300 Hz.

Description

[Technical field]

[0001] (Priority information) This application claims priority to a Chinese application having application number 202210877819.0, filed on July 25, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present specification relates to the technical field of electronic devices, and in particular to energy conversion devices, speakers and sound output devices. [Background technology]

[0003] Speakers are widely used in daily life. Conventional speakers often have problems such as low sensitivity, large mass, offset of magnets inside the energy conversion device, low magnetic field strength, etc. This specification provides an energy conversion device, a speaker, and an audio output device that solve the above problems. Summary of the Invention [Means for solving the problem]

[0004] An energy conversion device according to one embodiment of the present specification includes a magnetic circuit system including a magnet assembly and a magnetic flux conductive cover installed to at least partially surround the magnet assembly, a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet distributed on both sides of the magnet assembly along the vibration direction of the energy conversion device and elastically supporting the magnet assembly, and a coil installed in the magnetic circuit system, within the magnetic field range of the magnet assembly, and having an overall DC impedance in the range of 6Ω to 10Ω.

[0005] An energy conversion device according to one embodiment of the present specification includes a magnetic circuit system including a magnet assembly and a magnetic flux conducting cover arranged to at least partially surround the magnet assembly, and a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet distributed on both sides of the magnet assembly along the vibration direction of the magnet assembly and elastically supporting the magnet assembly within the magnetic flux conducting cover, respectively, and the energy conversion device has a resonant peak frequency of less than 300 Hz.

[0006] An energy conversion device according to an embodiment of the present specification includes a magnetic circuit system including a magnet assembly and a magnetic flux conductive cover installed to at least partially surround the magnet assembly, and vibration transmission sheets including a first vibration transmission sheet and a second vibration transmission sheet respectively distributed on both sides of the magnet assembly along a vibration direction of the magnet assembly and elastically supporting the magnet assembly within the magnetic flux conductive cover, wherein the first vibration transmission sheet or the second vibration transmission sheet has an equivalent stiffness of 4.7×10 in any direction in a plane perpendicular to the vibration direction of the magnet assembly. 4 Greater than N / m.

[0007] An energy conversion device according to one embodiment of the present specification includes a magnetic circuit system including a magnet, a magnetic flux conducting plate and a magnetic flux conducting cover, wherein the magnet and the magnetic flux conducting plate are arranged along the vibration direction of the energy conversion device, and a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet fixed to both sides of the magnet along the vibration direction of the magnet assembly and elastically supporting the magnet, respectively, wherein a first hole is provided in the magnet, a second hole is provided in the magnetic flux conducting plate, and the second hole is arranged corresponding to the first hole.

[0008] An energy conversion device according to one embodiment of the present specification includes a magnetic circuit system including a magnet, a magnetic flux conducting plate, and a magnetic flux conducting cover, wherein the magnet and magnetic flux conducting plate are arranged along the vibration direction of the energy conversion device, and a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet, wherein the first vibration transmission sheet or the second vibration transmission sheet is fixed to both sides of the magnet along the vibration direction of the energy conversion device, and elastically supports the magnet, wherein the ratio of the thickness of the magnetic flux conducting plate to the thickness of the magnet is in the range of 0.05 to 0.35.

[0009] An energy conversion device according to one embodiment of the present specification includes a magnetic circuit system including a magnet, a magnetic flux conducting plate, and a magnetic flux conducting cover, in which the magnet and the magnetic flux conducting plate are arranged along the vibration direction of the energy conversion device, and a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet, in which the first vibration transmission sheet or the second vibration transmission sheet is fixed to both sides of the magnet along the vibration direction of the energy conversion device and elastically supports the magnet, and at least one of the magnet, the magnetic flux conducting plate, and the magnetic flux conducting cover includes a plurality of magnetic parts having different magnetization directions.

[0010] A speaker according to one embodiment of the present specification includes a housing, an electronic component, and an energy conversion device described in any embodiment of the present specification, wherein the housing forms a cavity to accommodate the energy conversion device and the electronic component.

[0011] An audio output device according to one embodiment of the present specification includes a fixing assembly and a speaker according to any embodiment of the present specification, the fixing assembly being connected to the speaker. [Brief description of the drawings]

[0012] [Figure 1(a)] FIG. 2 is a schematic diagram of a speaker installation according to some embodiments of the present disclosure. [Figure 1(b)] FIG. 2 is a schematic diagram of a speaker installation according to some embodiments of the present disclosure. [Figure 1(c)] FIG. 2 is a schematic diagram of a speaker installation according to some embodiments of the present disclosure. [Figure 2(a)] FIG. 1 is a schematic diagram of a speaker according to some embodiments of the present disclosure. [Figure 2(b)] 1 is a schematic diagram of a magnetic flux conducting cover according to some embodiments of the present disclosure; [Figure 2(c)] 1 is a schematic diagram of an example first magnetic flux conducting plate and first coil location in accordance with certain embodiments of the present disclosure; [Diagram 3] FIG. 1 is a schematic diagram of a speaker according to some embodiments of the present disclosure. [Figure 4] FIG. 1 is a schematic diagram of a speaker according to some embodiments of the present disclosure. [Figure 5(a)] FIG. 1 is a schematic diagram of a speaker according to some embodiments of the present disclosure. [Figure 5(b)] 11A-11C are comparative diagrams showing the effect on the magnetic field of a coil of different distances between a bone conduction speaker and an air conduction speaker according to some embodiments of the present application. [Figure 6] FIG. 1 is a schematic diagram of an energy conversion device according to some embodiments of the present disclosure. [Figure 7(a)] FIG. 2 is an exploded view of an energy conversion device according to some embodiments of the present disclosure. [Figure 7(b)] FIG. 1 is a comparison diagram of impedance of energy conversion devices having a single voice coil structure and a dual voice coil structure according to some embodiments of the present application. [Figure 7(c)] 1 is a partial schematic view of a cylindrical magnetic flux conducting cover according to some embodiments of the present application. [Figure 7(d)] FIG. 2 is a schematic diagram of a cup-shaped magnetic flux conducting cover according to some embodiments of the present application. [Figure 8] FIG. 4 is a comparison diagram of frequency response curves when a magnetic flux conducting cover has grooves and when it does not have grooves. [Figure 9(a)] FIG. 2 is a schematic plan view of a magnetic flux conducting plate according to some embodiments herein. [Figure 9(b)]FIG. 2 is a schematic plan view of a magnetic flux conducting plate according to some embodiments herein. [Figure 9(c)] FIG. 2 is a schematic plan view of a magnetic flux conducting plate according to some embodiments herein. [Figure 10] FIG. 10 is a comparison of frequency response curves for a magnetic flux conducting plate with and without holes in accordance with certain embodiments herein; [Figure 11] FIG. 10 is a comparison of frequency response curves for a magnetic flux conducting plate with and without holes in accordance with certain embodiments herein; [Figure 12] FIG. 11 is a comparison diagram of BL value curves for different distances from a second hole on a magnetic flux conducting plate to the center of the magnetic flux conducting plate according to some embodiments herein. [Figure 13] FIG. 10 is a comparison diagram of frequency response curves for different diameters of second holes according to some embodiments herein. [Figure 14(a)] FIG. 11 is a comparison diagram of BL value curves for different diameters of second holes according to some embodiments herein. [Figure 14(b)] FIG. 11 is a comparative diagram of acceleration curves when the mass of speakers according to some embodiments of the present specification is within a range of 2 g to 5 g. [Figure 15(a)] 1 is a schematic diagram of a vibration transmitting sheet according to some embodiments of the present specification. [Figure 15(b)] 1 is a schematic diagram of a vibration transmitting sheet according to some embodiments of the present specification. [Figure 15(c)] 1 is a schematic diagram of a vibration transmitting sheet according to some embodiments of the present specification. [Figure 16(a)] 1 is a schematic diagram of a vibration transmitting sheet according to some embodiments of the present specification. [Figure 16(b)] 1 is a schematic diagram of a vibration transmitting sheet according to some embodiments of the present specification. [Figure 17(a)] FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 17(b)]FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 17(c)] FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 17(d)] FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 17(e)] FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 17(f)] FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 17(g)] FIG. 1 is a schematic diagram of a Halbach array type magnetic circuit system according to some embodiments of the present disclosure. [Figure 18] FIG. 11 is a comparative diagram of BL value curves when the magnetic circuit systems according to some embodiments of the present specification have different magnetic portion arrangements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In order to more clearly describe the technical means of the embodiments of the present application, the drawings necessary for the description of the embodiments are briefly described below. Obviously, the drawings described below are only some examples or embodiments of the present application, and those skilled in the art can apply the present application to other similar scenarios based on these drawings without creative efforts. Unless otherwise clear from the language environment or specified, in the drawings, the same symbols represent the same structures or operations.

[0014] It should be understood that the terms "system," "apparatus," "unit," and / or "module" used herein are ways of distinguishing between different levels of assemblies, parts, components, portions, or structures, however, other terms may be used in place of the above terms if they accomplish the same purpose.

[0015] As used herein and in the claims, unless the context clearly dictates otherwise, terms such as "a," "one," "one kind," and / or "the" do not specifically refer to the singular but may include the plural. In general, the terms "comprise" and "containing" are merely intended to indicate the inclusion of explicitly identified steps and elements, and these steps and elements are not intended to be an exclusive listing, and a method or apparatus may include other steps or elements.

[0016] The embodiments of the present specification describe an audio output device 100. In some embodiments, the audio output device 100 may include a speaker 10 and a fixing assembly 20, where the speaker 10 is connected to the fixing assembly 20. The fixing assembly 20 may support the speaker 10 to be mounted at a mounting position. In some embodiments, the mounting position may be a specific position on the user's head. For example, the mounting position may include the ear, the mastoid process, the temporal bone, the parietal bone, the frontal bone, etc. Also, for example, the mounting position may include a position on both the left and right sides of the head and in front of the user's ear on the sagittal axis of the human body. In some embodiments, the speaker 10 may include an energy conversion device, where the energy conversion device may convert an electrical signal (including audio information) into mechanical vibrations so that the user can hear the sound by the audio output device 100. Specifically, the mechanical vibrations generated by the speaker 10 may be transmitted mainly through a medium such as the user's skull (i.e., bone conduction) to form bone-conducted sound, may be transmitted mainly through a medium such as air (i.e., air conduction) to form air-conducted sound, or may transmit sound by a combination of bone conduction and air conduction. For more information on the speaker 10, please refer to other parts of this specification, such as Figures 2(a) to 4 and their related descriptions.

[0017] In some embodiments, the fastening assembly 20 may be arranged in a ring shape and wrapped around the user's head through the user's forehead and back of the head. In some embodiments, the fastening assembly 20 may be a back-hanging structure that forms a curved shape and fits the back of the user's head. In some embodiments, the fastening assembly 20 may be an ear-hanging structure that is hooked onto the user's auricle and has a curved portion that fits the human ear. In some embodiments, the fastening assembly 20 may be a glasses frame structure that has a pad and temples on both sides and can be worn on the user's face and ears. For more embodiments of the fastening assembly 20, please refer to Figures 1(a) to 1(c) and their related descriptions.

[0018] 1(a) to 1(c) are schematic diagrams of how the sound output device 100 according to some embodiments of the present specification is worn. In some embodiments, as shown in FIG. 1(a), the fixing assembly 20 may be installed in an annular shape and wrapped around the ear of the user so that the speaker 10 is fixed to the user's face and close to the user's ear canal. In some embodiments, as shown in FIG. 1(b), the fixing assembly 20 may be installed as an ear-hanging and back-hanging structure and may be wrapped around the back of the user's head and the auricle in cooperation with each other so that the speaker 10 is fixed to the user's face and close to the user's ear canal. In some embodiments, as shown in FIG. 1(c), the fixing assembly 20 may be a head beam structure that forms a curved shape and wrapped around the top of the user's head so that the speaker 10 is fixed to the user's face and close to the user's ear canal.

[0019] In some embodiments, the sound output device 100 may include at least two speakers 10. The at least two speakers 10 can both convert an electrical signal into mechanical vibrations so that the sound output device 100 achieves a stereo effect. For example, the sound output device 100 may include two speakers 10. The two speakers 10 may be installed on the left and right ears of a user, respectively. In some application scenarios where the requirements for stereo are not particularly high (e.g., hearing aids for hearing-impaired patients, presenting lines to a presenter during a live broadcast, etc.), the sound output device 100 may be installed with only one speaker 10.

[0020] When the sound output device 100 includes two speakers 10, the fixing assembly 20 may exemplarily include two ear-hanging assemblies and one back-hanging assembly. Both ends of the back-hanging assemblies are respectively connected to one end of the corresponding ear-hanging assemblies, and the other end of each ear-hanging assembly away from the back-hanging assembly is respectively connected to the corresponding speaker 10. Specifically, the back-hanging assembly may be installed in a curved shape so as to be wrapped around the back side of the user's head, and the ear-hanging assembly may be installed in a curved shape so as to be hung between the user's ears and head, thereby making it easy to realize the wearing demand of the sound output device 100. In this way, when the sound output device 100 is in a wearing state, the two speakers 10 are respectively located on the left and right sides of the user's head, and press the user's head with the cooperative action of the fixing assembly 20, so that the user can hear the sound output from the sound output device 100.

[0021] In some embodiments, the speaker 10 in this specification may be a bone conduction speaker and / or an air conduction speaker. In some embodiments, the sound output device 100 may be an electronic device having an audio function, for example, the sound output device 100 may be an electronic device such as a music earphone, a hearing aid earphone, a bone conduction earphone, a hearing aid, audio glasses, a smart helmet, a VR device, an AR device, etc.

[0022] FIG. 2(a) is a schematic diagram of a speaker 10 according to some embodiments of the present specification. As shown in FIG. 2(a), the speaker 10 may include a housing 11, an energy conversion device 12, and a vibration panel 13. A receiving cavity for receiving the energy conversion device 12 may be formed in the housing 11. The energy conversion device 12 may be installed in the receiving cavity of the housing 11, and the vibration panel 13 may be connected to the energy conversion device 12, and may transmit mechanical vibrations generated by the energy conversion device 12 to a user. The fixing assembly 20 may be connected to the outside of the housing 11. In some embodiments, the energy conversion device 12 converts an electric signal into mechanical vibrations, and the vibration panel 13 may contact the skin of a user in a worn state, and the mechanical vibrations generated by the energy conversion device 12 are transmitted to the vibration panel and act on the auditory nerve of the user through the skin, bones, and / or tissues of the user, thereby forming bone conduction sound. It should be noted that the housing 11 is not limited to the shape shown in the figures and may be rectangular, circular, diamond, polygonal, or any other irregular shape, or combinations thereof.

[0023] In some embodiments, the speaker 10 may further include a vibration-damping sheet 14. The energy conversion device 12 may be hung in the receiving cavity of the housing 11 by the vibration-damping sheet 14. The vibration panel 13 may not be in contact with the housing 11, in which case the vibration-damping sheet 14 may reduce or even prevent the mechanical vibration generated by the energy conversion device 12 from being transmitted to the housing 11, thereby to a certain extent preventing the housing 11 from vibrating the air outside the speaker 10, which is advantageous to reducing sound leakage from the speaker 10. In some embodiments, the housing 11 has an open end, and the diaphragm panel 13 is installed outside the housing 11 and faces the open end, i.e., the edge of the diaphragm panel 13 is not connected to the open end of the housing 11, and a connecting rod 131 is installed between the diaphragm panel 13 and the energy conversion device 12, and one end of the connecting rod 131 is connected to the energy conversion device 12 and the other end passes through the open end of the housing 11 and is connected to the diaphragm panel 13, so that the vibrating diaphragm panel 13 and the energy conversion device 12 do not contact the housing 11, thereby reducing sound leakage of the speaker 10. In some embodiments, the vibration-damping sheet 14 may be connected between the connecting rod 131 and the housing 11 to realize the hooking of the diaphragm panel 13 and the energy conversion device 12. In some embodiments, the housing 11 may be formed with at least one through hole (also called a "sound leakage reduction hole") that communicates the receiving cavity of the housing 11 with the outside of the speaker 10, so as to reduce sound leakage of the speaker 10.

[0024] In some embodiments, the speaker 10 may further include a face rest cover (not shown) connected to the diaphragm panel 13, and the face rest cover is in contact with the user's skin, i.e., the diaphragm panel 13 can be in contact with the user's skin through the face rest cover. The Shore hardness of the face rest cover may be smaller than the Shore hardness of the diaphragm panel 13, i.e., the face rest cover may be softer than the diaphragm panel 13. For example, the material of the face rest cover may be a soft material such as silicone rubber, and the material of the diaphragm panel 13 may be a hard material such as polycarbonate or glass fiber reinforced plastic. In this way, the wearing comfort of the speaker 10 can be improved, the speaker 10 can be more closely attached to the user's skin, and the sound quality of the speaker 10 can be further improved. In some embodiments, the face rest cover may be removably connected to the diaphragm panel 13 so that the user can easily replace it. For example, the face rest cover may be fitted into the diaphragm panel 13.

[0025] As shown in FIG. 2(a), the energy conversion device 12 may include a bracket 121, a vibration transmission sheet 122, a magnetic circuit system 123, and a coil 124. In some embodiments, the vibration panel 13 may be connected to the bracket 121. For example, as shown in FIG. 2(a), the bracket 121 may be connected to an end of the connecting rod 131 away from the vibration panel 13. The bracket 121 may be connected to the magnetic circuit system 123 via the vibration transmission sheet 122 so as to hook the magnetic circuit system 123 into the receiving cavity of the housing 11. In some embodiments, the vibration damping sheet 14 may connect the bracket 121 and the housing 11 so as to hook the energy conversion device 12 into the receiving cavity of the housing 11. The coil 124 may extend into the magnetic gap of the magnetic circuit system 123 along the vibration direction of the energy conversion device 12.

[0026] In some embodiments, the magnetic circuit system 123 may include a magnet assembly 1231 and a magnetic flux conducting cover 1232. The magnetic flux conducting cover 1232 may be fitted to the coil 124, the magnet assembly 1231 may be installed within the coil 124, and the magnetic flux conducting cover 1232 and the magnet assembly 1231 are spaced apart in a direction perpendicular to the vibration direction, such that the aforementioned magnetic gap is formed between the inner wall of the magnetic flux conducting cover 1232 and the outside of the magnet assembly 1231. In some embodiments, the coil 124 may be fitted to the outside of the magnet assembly 1231 around an axis parallel to the vibration direction of the energy conversion device 12. In some embodiments, the magnetic flux conducting cover 1232 of the magnetic circuit system 123 is fitted to the outside of the coil 124 around an axis parallel to the vibration direction of the energy conversion device 12, i.e., the magnetic flux conducting cover 1232 and the magnet assembly 1231 are spaced apart in a direction perpendicular to the vibration direction of the energy conversion device 12. Specifically, the coil 124 may be connected to the magnetic flux conducting cover 1232. In some embodiments of the present application, the coil 124 is in close contact with the inner wall of the magnetic flux conducting cover 1232. In some embodiments, the vibration transmitting sheet 122 may be connected between the magnetic flux conducting cover 1232 and the magnet assembly 1231, and may elastically support the magnet assembly 1231. For example, the vibration transmitting sheet 122 and the magnetic circuit system 123 may be arranged along the vibration direction, and a side surface of the vibration transmitting sheet 122 perpendicular to the vibration direction may be connected to an end portion of the magnetic flux conducting cover 1232 perpendicular to the vibration direction to realize the fixing of the magnetic circuit system 123. Note that, in other embodiments of the present application, the periphery of the vibration transmitting sheet 122 may be connected to the inner wall or other position of the magnetic flux conducting cover 1232 to realize the fixing of the magnetic circuit system 123 to the magnetic flux conducting cover 1232.

[0027] In some embodiments, the coil 124 may include a first coil 1241 and a second coil 1242. In some embodiments, the first coil 1241 may extend into the magnetic gap of the magnetic circuit system 123 from a side close to the diaphragm panel 13 along the vibration direction, and the second coil 1242 may extend into the magnetic gap of the magnetic circuit system 123 from a side away from the diaphragm panel 13 along the vibration direction. In some embodiments, in order to simplify the assembly process, the first coil 1241 and the second coil 1242 may extend together into the magnetic gap of the magnetic circuit system 123 from a side close to the diaphragm panel 13. In some embodiments, the energy conversion device 12 may further include a holding portion that holds the shape of the first coil 1241 and the second coil 1242. For example, the first coil 1241 and the second coil 1242 may be an integral structure. Specifically, the first coil 1241 and the second coil 1242 are wound on a shape-retaining material and then adhered to the outside of the first coil 1241 and the second coil 1242 using a retaining part (e.g., a retaining material such as a high-temperature tape) to form an integrated structure. The first coil 1241 and the second coil 1242 fixed to the retaining part extend into the magnetic gap of the magnetic circuit system 123 from the same side of the diaphragm panel 13, which simplifies the assembly process of the coil 124. In some embodiments, the two coils are formed by winding the same wire, or parts of the two coils are connected, so that the two coils have only two lead wires to and from each other, which can facilitate wiring and subsequent electrical connection with other structures.

[0028] In some embodiments, the vibration transmission sheet 122 may include a first vibration transmission sheet 125 and a second vibration transmission sheet 126. In the vibration direction of the energy conversion device 12, the first vibration transmission sheet 125 and the second vibration transmission sheet 126 may elastically support the magnet assembly 1231 from both sides facing each other of the magnet assembly 1231, respectively. Thus, in the embodiments of the present specification, the magnet assembly 1231 is elastically supported on both sides facing each other in the vibration direction of the energy conversion device 12, and there is no abnormal vibration such as noticeable shaking, and thus it is advantageous to improve the vibration stability of the energy conversion device 12.

[0029] 2(a), edge regions 1253 on opposite sides of the first vibration transmitting sheet 125 in the vibration direction are respectively connected to a side of the bracket 121 close to the magnetic circuit system 123 and a side of the magnetic flux conducting cover 1232 close to the bracket 121. An edge region 1263 of the second vibration transmitting sheet 126 is connected to a side of the magnetic flux conducting cover 1232 away from the bracket 121. In some embodiments, the magnetic flux conducting cover 1232 may be a cylindrical structure with both ends open (e.g., as shown in Figs. 2(a) and 2(b)), a cup-shaped structure with one end open (e.g., as shown in Fig. 7(d)), etc. In some embodiments, the magnetic flux conducting cover 1232 may be provided with holes (for example, holes may be provided in the side wall of the magnetic flux conducting cover having a cylindrical structure (for example, as shown in FIG. 7(c)), and holes may be provided in each or all of the bottom and side of the magnetic flux conducting cover having a bowl-shaped structure (for example, as shown in FIG. 7(d)) ​​to reduce the cavity sound effect of the magnetic circuit system 123 and reduce sound leakage from the audio output device 100. In some embodiments, the magnetic flux conducting cover 1232 may be provided with a sealed structure so that sound generated in the magnetic circuit system 123 does not leak to the outside. FIG. 2(b) is a schematic diagram of the magnetic flux conducting cover 1232 according to some embodiments of the present specification. As shown in FIG. 2(b), the cover plate 1232-1 and the cover plate 1232-2 can seal both ends of the cylindrical energy conversion device 12 along the vibration direction, which are open at both ends, to form a sealed magnetic flux conducting cover 1232. It should be understood that the cover plate is merely exemplary, and that other methods (e.g., cover membranes, etc.) can be used to seal both ends of the open-ended cylindrical structure along the vibration direction to form a sealed magnetic flux conducting cover 1232. In some other embodiments where the requirements for the concentration of the magnetic field generated by the magnet assembly 1231 are not high, the magnetic flux conducting cover 1232 can be replaced with a non-magnetic member such as a plastic bracket. On this basis, the edge regions of the first vibration transmitting sheet 125 and the second vibration transmitting sheet 126 can be connected to both ends of the plastic bracket, respectively.

[0030] In some embodiments, the magnet assembly 1231 may include a magnet 1233 and a magnetic flux conducting plate. In some embodiments, the magnet 1233 and the magnetic flux conducting plate are arranged along the vibration direction of the energy conversion device 12. In some embodiments, the magnetic flux conducting plate may be arranged on one side or both sides of the magnet 1233 in the vibration direction of the energy conversion device 12. In some embodiments, the magnetic flux conducting plate may include a first magnetic flux conducting plate 1234 and a second magnetic flux conducting plate 1235 located on opposite sides of the magnet 1233 in the vibration direction of the energy conversion device 12. The first vibration transmitting sheet 125 may support the magnet assembly 1231 from a side of the first magnetic flux conducting plate 1234 away from the second magnetic flux conducting plate 1235, and the second vibration transmitting sheet 126 may support the magnet assembly 1231 from a side of the second magnetic flux conducting plate 1235 away from the first magnetic flux conducting plate 1234. For example, the central region 1252 of the first vibration transmitting sheet 125 is connected to the side of the first magnetic flux conducting plate 1234 remote from the second magnetic flux conducting plate 1235, and the central region 1262 of the second vibration transmitting sheet 126 is connected to the side of the second magnetic flux conducting plate 1235 remote from the first magnetic flux conducting plate 1234. In some embodiments, corners of the magnetic flux conducting plates (e.g., the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235) remote from the magnet 1233 may be chamfered. For example, by chamfering the corners of both opposing sides of the first magnetic flux conducting plate 1234 and the second magnetic flux conducting plate 1235 (i.e., the corners remote from the magnet 1233), the distribution of the magnetic field formed by the magnetic circuit system 123 can be adjusted and the magnetic field can be more concentrated.In some embodiments, in the vibration direction of the energy conversion device 12, the half height position of the first coil 1241 and the half thickness position of the side parallel to the vibration direction of the first magnetic flux conducting plate 1234 may be equal, and the half height position of the second coil 1242 and the half thickness position of the side parallel to the vibration direction of the second magnetic flux conducting plate 1235 may be equal, so that the magnetic field can be concentrated and distributed in the rectangular portion other than the chamfered portion of the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235. FIG. 2(c) is a schematic diagram of the positions of an example first magnetic flux conducting plate 1234 and the first coil 1241 according to some embodiments of the present specification. 2(c), along the vibration direction of the energy conversion device 12, a half height position H1 of the first coil 1241 and a half thickness position H2 of the side 1234-1 of the first magnetic flux conducting plate 1234 parallel to the vibration direction are at the same height, and both are on a contour line L. In some embodiments, in order to simplify the manufacture of the magnetic flux conducting plates (e.g., the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235), corners of the magnetic flux conducting plates (e.g., the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235) away from the magnet 1233 may be right angles. For example, chamfering may not be performed on both opposing corners of the first magnetic flux conducting plate 1234 and the second magnetic flux conducting plate 1235 (i.e., corners away from the magnet 1233). In this case, in the vibration direction of the energy conversion device 12, the half height position of the first coil 1241 and the half thickness position of the first magnetic flux conducting plate 1234 may be equal, and the half height position of the second coil 1242 and the half thickness position of the second magnetic flux conducting plate 1235 may be equal, so that the magnetic field can be distributed intensively on the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235. Compared with the first magnetic flux conducting plate 1234 and the second magnetic flux conducting plate 1235 that have been chamfered, the thickness of the first magnetic flux conducting plate 1234 and the second magnetic flux conducting plate 1235 that have not been chamfered may be smaller so as to achieve the purpose of reducing the weight and volume of the entire energy conversion device 12.

[0031] In some embodiments, the magnetic flux conductive cover 1232 may be connected to the bracket 121 so as to hang the energy conversion device 12 in the receiving cavity of the housing 11, and the bracket 121 may be connected to the housing 11 via the vibration-damping sheet 14. In this case, as shown in FIG. 2(a), both ends perpendicular to the vibration direction of the edge region 1253 of the first vibration-transmitting sheet 125 are connected to the bracket 121 and the magnetic flux conductive cover 1232, both ends perpendicular to the vibration direction of the edge region 1263 of the second vibration-transmitting sheet 126 are connected to the magnetic flux conductive cover 1232, and the diaphragm panel 13 may be connected to the bracket 121 and not connected to the open end of the housing 11.

[0032] In some embodiments, if the rigidity of the vibration-damping sheet 14 is too small, the magnetic circuit system 123 is not easily stably hooked in the housing 11 by the vibration-damping sheet 14, and thus the stability when the energy conversion device 12 vibrates is likely to deteriorate, whereas if the rigidity of the vibration-damping sheet 14 is too large, the vibration of the energy conversion device 12 is easily transmitted to the housing 11 via the vibration-damping sheet 14, and thus the sound leakage of the speaker 10 is likely to become excessive. In some embodiments, in order to ensure good stability when the energy conversion device 12 vibrates and reduce sound leakage of the speaker 10, the ratio of the rigidity of the vibration-damping sheet 14 to the rigidity of the first vibration transmission sheet 125 (or the second vibration transmission sheet 126) may be within a range of 0.1 to 5.

[0033] FIG. 3 is a schematic diagram of a speaker 10 according to some embodiments of the present specification. As shown in FIG. 3, the speaker 10 of the embodiment is basically the same as the embodiment shown in FIG. 2(a), and the main difference is that in this embodiment, the magnetic flux conductive cover 1232 is installed so as to be rigidly connected to the housing 11 or the diaphragm panel 13, that is, in this embodiment, the vibration-damping sheet 14 does not need to be present. In this embodiment, the magnetic flux conductive cover 1232 is in close contact with the inner wall of the housing 11, which is advantageous in fully utilizing the internal space of the housing 11 and realizing a miniaturization of the speaker 10. Note that in other embodiments of the present application, the magnetic flux conductive cover 1232 may be rigidly connected to the housing 11 or the diaphragm panel 13 by other fixing structures. In some embodiments, an edge region (e.g., edge region 1253 or edge region 1263) of any one of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 may be connected to the open end of the housing 11 by one or a combination of assembly methods such as fastening, adhesion, etc., and the diaphragm panel 13 is connected to the open end of the housing 11 to form a closed cavity. In some embodiments, a side of any one of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 close to the diaphragm panel 13 is connected to the diaphragm panel 13, and the diaphragm panel 13 is connected to the open end of the housing 11. In some embodiments, the diaphragm panel 13 and the housing 11 may be made of the same material and be integrally molded. In some embodiments, the diaphragm panel 13 and the housing 11 may be made of different materials and be connected to the housing 11 by one or a combination of assembly methods such as fastening, adhesion, etc.

[0034] In some embodiments, the speaker 10 may further include electronic components installed in the receiving cavity of the housing 11 or in close contact with the outside of the housing 11. In some embodiments, the electronic components may include vibration-sensitive components and vibration-insensitive components. The vibration-sensitive components may include an air-conduction speaker, an acceleration sensor, etc. The vibration-insensitive components may include a battery, a circuit board, etc. The battery may supply power to the speaker 10 so that the speaker 10 can operate. The circuit board may be integrated with a signal processing circuit that processes the electric signal. In some embodiments, the signal processing may include frequency modulation processing, amplitude modulation processing, filtering processing, noise reduction processing, etc. The air-conduction speaker converts the electric signal into a vibration signal (sound wave), transmits it to the auditory nerve through the air, and can be sensed by the user. The acceleration sensor can measure the vibration acceleration of the vibration panel 13. For a description of the installation of the air-conduction speaker and the acceleration sensor, the following may be referred to, for example, the description of FIG. 4 to FIG. 9(c).

[0035] 2(a) and 3, the speaker 10 may be a bone conduction speaker. Hereinafter, with reference to Figs. 4 to 9(c) and the like, various embodiments in which the sound output device 100 can be implemented as a bone air conduction speaker or a bone air conduction earphone will be described.

[0036] FIG. 4 is a schematic diagram of a speaker 10 according to some embodiments of the present specification. The speaker 10 shown in FIG. 4 is basically the same as the speaker 10 shown in FIG. 2(a), and the main difference is that the electronic components of the speaker 10 include an air conduction speaker, and the air conduction speaker is installed in the receiving cavity of the housing 11. As shown in FIG. 4, the speaker 10 includes an energy conversion device 12 and a housing 11 that accommodates the energy conversion device 12, and the energy conversion device 12 includes a magnetic circuit system 123 (including a magnetic flux conductive cover 1232 and a magnet assembly 1231), a coil 124 (including a first coil 1241 and a second coil 1242), and a vibration transmission sheet 122 (including a first vibration transmission sheet 125 and a second vibration transmission sheet 126). The coil 124 is installed in the magnetic circuit system 123 so that the magnetic fields B1 and B2 of the magnetic circuit system 123 pass through the coil 124. The first vibration transmission sheet 125 and the second vibration transmission sheet 126 elastically support the magnet assembly 1231. The air conduction speaker includes a diaphragm 15 connected between the magnet assembly 1231 and the housing 11, and the diaphragm 15 divides the internal space of the housing 11 (i.e., the above-mentioned storage cavity) into a front cavity 111 close to a skin contact area (e.g., the diaphragm 13) and a rear cavity 112 away from the above-mentioned skin contact area. In other words, when a user wears the speaker 10, the front cavity 111 is closer to the user than the rear cavity 112. In some embodiments, the housing 11 is provided with a sound emission hole 113 communicating with the rear cavity 112, and the diaphragm 15 can generate air conduction sound that is transmitted to a human ear through the sound emission hole 113 during the process of the energy conversion device 12 and the housing 11 moving relative to each other. In this way, sound generated in the rear cavity 112 is transmitted through the sound emission hole 113 and acts on the user's eardrum via the air, so that the user can also hear air-conducted sound through the speaker 10.

[0037] In some embodiments, the diaphragm 15 of the air conduction speaker is connected between the magnet assembly 1231 and the housing 11 of the energy conversion device 12, and the vibration direction of the diaphragm 15 is parallel to the vibration direction of the energy conversion device 12. As shown in FIG. 4, when the energy conversion device 12 moves the skin contact area toward the user's face, it can be simply considered that the bone conduction sound is enhanced. At the same time, the part of the housing 11 corresponding to the skin contact area moves toward the user's face, and the magnet assembly 1231 moves away from the user's face due to the action-reaction relationship, so that the air in the rear cavity 112 is compressed and the air pressure increases, and as a result, the sound transmitted through the sound outlet 113 is enhanced, and the air conduction sound is enhanced. Therefore, the bone conduction sound and the air conduction sound of the speaker 10 can be enhanced at the same time, and accordingly, when the bone conduction sound is attenuated, the air conduction sound is also attenuated. Based on this, the bone conduction sound and the air conduction sound generated by the speaker 10 have the characteristic of being in phase with each other. Furthermore, when the front cavity 111 is a sealed cavity, the front cavity 111 and the rear cavity 112 are substantially separated by structural members such as the diaphragm 15 and the energy conversion device 12, so that the change pattern of the air pressure in the front cavity 111 is just the opposite to the change pattern of the air pressure in the rear cavity 112. In some embodiments, the housing 11 may be provided with a decompression hole communicating with the front cavity 111, or may be provided with an opening for the front cavity 111, so that the front cavity 111 can communicate with the outside environment, i.e., air can freely enter and exit the front cavity 111. In this way, the change in the air pressure in the rear cavity 112 can be prevented from being hindered by the front cavity 111 as much as possible, thereby effectively improving the acoustic expressiveness of the air-conducted sound generated by the speaker 10. In some embodiments, the decompression holes located in the front cavity 111 may be offset from the sound emission holes 113 located in the rear cavity 112, ie, they may not be adjacent to each other.For example, the decompression hole is provided on one side of the housing 11, and the sound emission hole 113 is provided on the other side of the housing 11 relative to the decompression hole, thereby avoiding as much as possible the muffling phenomenon caused by the phases of the two being reversed.

[0038] In some embodiments, in order to prevent the air conduction speaker from resonating under the influence of the vibration of the energy conversion device 12 and generating a sound leakage peak, the air conduction vibration direction of the air conduction speaker can be made different from the vibration direction of the energy conversion device 12 (i.e., the bone conduction vibration direction) to prevent mutual influence in the same direction. FIG. 5(a) is a schematic configuration diagram of a speaker 10 according to some embodiments of the present specification. As shown in FIG. 5(a), an air conduction speaker 16 is installed on a side wall of a housing 11. The air conduction speaker 16 is connected to the energy conversion device 12, and the energy conversion device 12 and the housing 11 in the speaker 10 form a bone conduction speaker, and the bone conduction speaker is combined with the air conduction speaker 16 to form a bone air conduction speaker. In some embodiments, the air conduction vibration direction of the air conduction speaker 16 is different from the vibration direction of the energy conversion device 12 (i.e., the bone conduction vibration direction). In some embodiments, the vibration direction of the energy conversion device 12 may be installed approximately perpendicular to the air conduction vibration direction of the air conduction speaker 16. For example, the vibration direction of the energy conversion device 12 may be set to be approximately perpendicular to the vibration direction of the diaphragm of the air conduction speaker 16 so as to reduce sound leakage from the air conduction speaker. "Approximately perpendicular" as described herein means that the included angle between the two corresponding parts is within a range of 90°±20°. For example, the included angle between the vibration direction of the energy conversion device 12 and the air conduction vibration direction of the air conduction speaker 16 (or the diaphragm of the air conduction speaker 16) is within a range of 90°±20°. For example, the vibration direction of the energy conversion device 12 may be set to be perpendicular to the diaphragm of the air conduction speaker 16. In some embodiments, the distance between the bone conduction speaker and the air conduction speaker 16 may be greater than a distance threshold to avoid an electromagnetic field being generated between the electromagnetic assembly of the bone conduction speaker and the electromagnetic assembly of the air conduction speaker 16 to affect the vibration output of the bone conduction speaker and the air conduction speaker 16. The "distance between the bone conduction speaker and the air conduction speaker 16" as described herein is the minimum distance between the magnetic assembly of the bone conduction speaker and the magnetic assembly of the air conduction speaker 16.FIG. 5(b) is a comparison diagram of the influence on the magnetic field of the coil of different distances between the bone conduction speaker and the air conduction speaker 16 according to some embodiments of the present application. As shown in FIG. 5(b), when the air conduction speaker 16 shown in FIG. 5(a) is magnetized rightward and the magnet assembly 1231 in the energy conversion device 12 is magnetized upward, the average magnetic field strength in the coil 1 located at the top in the energy conversion device 12 increases, and the average magnetic field strength in the coil 2 located at the bottom decreases. As the distance between the energy conversion device 12 and the air conduction speaker 16 of the bone conduction speaker increases, the magnets tend to disappear on the sides of the coil 1 and the coil 2. Therefore, the greater the distance between the energy conversion device 12 and the air conduction speaker 16 of the bone conduction speaker, the smaller the influence on the magnetic field of the coil in the energy conversion device 12. In some embodiments, the distance between the bone conduction speaker and the air conduction speaker 16 may be greater than 0.3 mm to reduce the influence on the magnetic field of the coil of the electromagnetic field generated between the electromagnetic assembly of the bone conduction speaker and the electromagnetic assembly of the air conduction speaker 16. For example, the distance between the bone conduction speaker and the air conduction speaker 16 may be greater than 0.4 mm.

[0039] In some embodiments, to avoid the acceleration sensor being affected by the vibration of the energy conversion device 12 when measuring the acceleration of the vibration panel 13, the vibration direction of the energy conversion device 12 may be approximately perpendicular to the vibration sensitive end of the acceleration sensor.

[0040] In addition, when the electronic component is a vibration-sensitive component such as an air conduction speaker or an acceleration sensor, the vibration-sensitive component is approximately perpendicular to the vibration direction of the energy conversion device 12 in order to avoid the vibration-sensitive component being affected by the vibration of the energy conversion device. In the present specification, "the vibration-sensitive component is approximately perpendicular to the vibration direction of the energy conversion device 12" means that when the vibration-sensitive component is an air conduction speaker, the vibration direction of the energy conversion device 12 is approximately perpendicular to the vibration direction of the diaphragm of the air conduction speaker, and when the vibration-sensitive component is an acceleration sensor, the vibration direction of the energy conversion device 12 is approximately perpendicular to the vibration-sensitive end of the acceleration sensor. When the electronic component is a vibration-insensitive component such as a battery or a circuit board, the battery or the circuit board may be disposed at any position in the housing 11 to realize an integrated design of the sound output device 100.

[0041] It should be noted that in some embodiments, the electronic components may include vibration-sensitive components and vibration-insensitive components, and the vibration-sensitive components may be approximately perpendicular to the vibration direction of the energy conversion device 12. For example, in some embodiments, the electronic components may include a vibration-sensitive acceleration sensor and a vibration-insensitive circuit board, and the acceleration sensor is mounted on the circuit board and accommodated in the housing of the speaker 10 to realize the integration of the sound output device. In this case, the acceleration sensor may be approximately perpendicular to the vibration direction of the energy conversion device 12.

[0042] FIG. 6 is a schematic diagram of an energy conversion device 12 according to some embodiments of the present specification. FIG. 7(a) is an exploded view of the energy conversion device 12 according to some embodiments of the present specification. The energy conversion device 12 shown in FIG. 6 and FIG. 7(a) may be used in any of the speakers 10 shown in FIG. 2(a) to FIG. 5(a). As shown in FIG. 6 and FIG. 7(a), the energy conversion device 12 may include a vibration transmission sheet 122, a magnetic circuit system 123, and a coil 124. The magnetic circuit system 123 may include a magnet assembly 1231 and a magnetic flux conductive cover 1232, and the magnet assembly 1231 may include a magnet 1233, and a first magnetic flux conductive plate 1234 and a second magnetic flux conductive plate 1235 located on both sides of the magnet 1233 facing away from each other in the vibration direction of the energy conversion device 12. In some embodiments, the magnetic flux conductive cover 1232 may be installed outside the magnet assembly 1231 around the axis. The coil 124 may be within the magnetic field range of the magnet assembly 1231. In some embodiments, the coil 124 may extend along the vibration direction of the energy conversion device 12 into a magnetic gap formed between the magnetic flux conducting cover 1232 and the magnet assembly 1231, and the magnetic flux conducting cover 1232 is fitted to the outside of the coil 124. In some embodiments, the inner wall of the magnetic flux conducting cover 1232 may be in close contact with the outer wall of the coil 124. In some embodiments, the vibration transmitting sheet 122 may include a first vibration transmitting sheet 125 and a second vibration transmitting sheet 126. The first vibration transmitting sheet 125 elastically supports the magnet assembly 1231 from a side of the first magnetic flux conducting plate 1234 away from the second magnetic flux conducting plate 1235, and the second vibration transmitting sheet 126 elastically supports the magnet assembly 1231 from a side of the second magnetic flux conducting plate 1235 away from the first magnetic flux conducting plate 1234. For example, the edge region 1253 of the first vibration transmission sheet 125 is connected to one end of the magnetic flux conducting cover 1232 along the vibration direction of the energy conversion device 12, and the edge region 1263 of the second vibration transmission sheet 126 is connected to the other end of the magnetic flux conducting cover 1232 along the vibration direction of the energy conversion device 12.

[0043] In some embodiments, the number of coils of the coil 124 along the radial direction of the energy conversion device 12 may be an even number to facilitate wiring of the lead wires of the coil 124 and to have the inlet and outlet wires of the coil 124 at the same position of the magnetic flux conducting cover 1232. For example, the number of radial turns of the coil is 2, 4, 6, 8, etc. As shown in Fig. 6, the radial direction of the energy conversion device 12 is a direction perpendicular to the axis of the energy conversion device 12 (or the vibration direction of the energy conversion device 12).

[0044] In some embodiments, the coil 124 may include a first coil 1241 and a second coil 1242. In some embodiments, the first coil 1241 and the second coil 1242 may be arranged along the vibration direction of the energy conversion device 12. The first coil 1241 and the second coil 1242 are connected in series or in parallel. For the first coil 1241 and the second coil 1242 connected in series or in parallel, in order to facilitate wiring of the lead wire of the first coil 1241 and the lead wire of the second coil 1242, the input position of each coil and the output position of each coil are both at the same position of the magnetic flux conductive cover 1232. The wire entry position of the first coil 1241 and the wire exit position of the first coil 1241 may be at the same position of the magnetic flux conductive cover 1232, and the wire entry position of the second coil 1242 and the wire exit position of the second coil 1242 may be at the same position of the magnetic flux conductive cover 1232. For example, the wire entry position of the first coil 1241, the wire exit position of the first coil 1241, the wire entry position of the second coil 1242 and the wire exit position of the second coil 1242 may be at an intermediate position of the magnetic flux conductive cover 1232 (for example, the intermediate position of the magnetic flux conductive cover 1232 in a direction perpendicular to the vibration direction of the energy conversion device 12). In some embodiments, the winding directions of the first coil 1241 and the second coil 1242 may be reversed, and the current directions in the first coil 1241 and the second coil 1242 may be reversed, so that the energy conversion device 12 vibrates relatively when driven by the dual coil (i.e., the coil 124 includes the first coil 1241 and the second coil 1242), and the vibration magnitude of the energy conversion device 12 can be increased compared to the single voice coil. In some embodiments, a lower high-frequency impedance can be achieved by using the dual coil structure. FIG. 7(b) is a comparison diagram of the impedance of the energy conversion device 12 having a single voice coil structure and a dual voice coil structure according to some embodiments of the present application. As shown in FIG. 7(b), the high-frequency impedance of the dual voice coil is lower than that of the single voice coil structure.

[0045] In some embodiments, if the impedance is too small, the current will increase at the same battery supply voltage, so more power will be consumed and the battery life will be shortened at the same battery capacity, while clipping distortion will occur if the battery cannot output the increased current. If the impedance is too large, the current will decrease at the same battery supply voltage, and the sensitivity will decrease, which will appear as a decrease in volume. Therefore, to balance battery life, distortion, sensitivity, volume, etc., the overall DC impedance of the coil 124 may be in the range of 6Ω to 10Ω. In some embodiments, the first coil 1241 and the second coil 1242 in the energy conversion device 12 can be designed according to the following demands.

[0046] First, in order to ensure that the overall DC impedance of the coil 124 consisting of the first coil 1241 and the second coil 1242 is within the range of 6Ω to 10Ω, the range of the DC impedance of the single coil (the first coil 1241 and the second coil 1242) may be different according to different connection methods (series connection or parallel connection). For example, in order to ensure that the overall DC impedance of the coil 124 is 8Ω, when the two coils are connected in series, the DC impedance of the single coil (the first coil 1241 and the second coil 1242) is 4Ω, and when the two coils are connected in parallel, the DC impedance of the single coil (the first coil 1241 and the second coil 1242) is 16Ω.

[0047] Next, in order to reduce the overall mass of the speaker 10 as much as possible, the volume of the magnetic flux conducting cover 1232 is reduced, thereby further reducing the mass of the magnetic flux conducting cover 1232. On the premise that the inner wall of the magnetic flux conducting cover 1232 and the outer wall of the coil 124 (including the first coil 1241 and the second coil 1242) are tightly attached to each other and the distance between the first coil 1241 and the second coil 1242 along the vibration direction of the energy conversion device 12 is within a range of 1.5 mm to 2 mm, the shape of the coil 124 (the first coil 1241 and the second coil 1242) may be made "elongated", that is, the axial height of the coil 124 may be increased and the radial width of the coil 124 may be decreased. In this case, the inner diameter of the magnetic flux conducting cover 1232 is also reduced, and the outer diameter of the magnetic flux conducting cover 1232 is reduced synchronously while the thickness of the magnetic flux conducting cover 1232 remains unchanged, whereby the mass of the magnetic flux conducting cover 1232 and the mass of the entire speaker 10 can be reduced accordingly. In some embodiments, the above demand can be met by designing parameters such as wire diameter, radial turns, and axial turns of the coil 124 (including the first coil 1241 and the second coil 1242) to make the shape of the coil 124 (the first coil 1241 and the second coil 1242) "elongated". In some embodiments, to make the shape of the coil 124 (the first coil 1241 and the second coil 1242) "elongated", the ratio of the axial height to the radial width of the first coil or the second coil may be 3 or more. For example, the ratio of the axial height to the radial width of the first coil or the second coil may be 3.5 or more.

[0048] Furthermore, since the axial height of the energy conversion device 12 is mainly limited by the size of the internal magnet assembly 1231, the axial height of the single coil (the first coil 1241 and / or the second coil 1242) may be set to be smaller than 2.85 mm in order to satisfy the dimensional requirements of the energy conversion device 12 (for example, in the case where the sound output device 100 is an earphone, in order to satisfy that the height of the speaker 10 in the earphone is smaller than 5.7 mm). For example, the axial height of the single coil (the first coil 1241 and / or the second coil 1242) may be about 2 mm.

[0049] To meet the above demands, in some embodiments, the first coil 1241 and the second coil 1242 may be connected in series. To ensure that the overall DC impedance of the coil 124 is within a range of 6Ω to 10Ω, the DC impedance of the first coil 1241 and / or the second coil 1242 may be within a range of 4Ω±1Ω. For example, to ensure that the overall DC impedance of the coil 124 is within a range of 7Ω to 9Ω, the DC impedance of the first coil 1241 and / or the second coil 1242 may be within a range of 3.5Ω to 4.5Ω. Also, for example, to ensure that the overall DC impedance of the coil 124 is within a range of 8Ω±0.8Ω, the DC impedance of the first coil 1241 and / or the second coil 1242 may be within a range of 4Ω±0.4Ω. In some embodiments, the wire diameter of the first coil 1241 and the second coil 1242 may be in the range of 0.11 mm to 0.13 mm.

[0050] In order to meet the above demand, in some embodiments, the first coil 1241 and / or the second coil 1242 may satisfy one of the following characteristics: a wire diameter of 0.11 mm, a number of radial turns of 2 to 6, and a number of axial layers of 8 to 20 layers; a wire diameter of 0.12 mm, a number of radial turns of 2 to 6, and a number of axial layers of 9 to 20 layers; or a wire diameter of 0.13 mm, a number of radial turns of 2 to 6, and a number of axial layers of 10 to 22 layers. For example, the first coil 1241 and / or the second coil 1242 may have a wire diameter of 0.11 mm, a number of radial turns of 3 to 5, and a number of axial layers of 12 to 20 layers. Also, for example, the first coil 1241 and / or the second coil 1242 may have a wire diameter of 0.12 mm, a number of radial turns of 3 to 5, and a number of axial layers of 14 to 20 layers. Further, for example, first coil 1241 and / or second coil 1242 may have a wire diameter of 0.13 mm, 3 to 4 radial turns, and 15 to 22 axial layers.

[0051] In some embodiments, the relationship between the wire diameter, the number of radial turns, the number of axial layers, and the DC impedance of the series-connected single coils (first coil 1241 and / or second coil 1242) is shown in Table 1.

[0052] [Table 1]

[0053] According to Table 1, in order to make the DC impedance of the single coil (the first coil 1241 or the second coil 1242) within the range of 4Ω±1Ω and to make the number of radial coils an even number, the exemplary first coil 1241 and / or the second coil 1242 may have a wire diameter of 0.11 mm, a number of radial turns of 4, and a number of axial layers of 12. In this case, the first coil 1241 and / or the second coil 1242 has a DC impedance of 4Ω. Also, for example, the wire diameter may be 0.12 mm, the number of radial turns of 4, and a number of axial layers of 14. In this case, the first coil 1241 and / or the second coil 1242 has a DC impedance of 3.93Ω. Also, for example, the wire diameter may be 0.12 mm, the number of radial turns of 4, and a number of axial layers of 15. In this case, the first coil 1241 and / or the second coil 1242 has a DC impedance of 4Ω. Furthermore, for example, the wire diameter may be 0.13 mm, the number of radial turns may be 4, and the number of axial layers may be 18. In this case, the first coil 1241 and / or the second coil 1242 has a DC impedance of 4.08Ω.

[0054] In some embodiments, the first coil 1241 and the second coil 1242 may be connected in parallel, and the DC impedance of the first coil 1241 and / or the second coil 1242 may be in the range of 12Ω to 20Ω, respectively, to ensure that the overall DC impedance of the coil 124 is in the range of 6Ω to 10Ω. For example, the DC impedance of the first coil 1241 and / or the second coil 1242 may be in the range of 16Ω±1.6Ω, respectively, to ensure that the overall DC impedance of the coil 124 is in the range of 8Ω±0.8Ω. In some embodiments, the wire diameter of the first coil 1241 and the second coil 1242 may be in the range of 0.07mm to 0.08mm.

[0055] To meet the above demands, in some embodiments, the first coil 1241 and / or the second coil 1242 may have 4 to 8 radial turns and 16 to 22 axial layers. For example, the first coil 1241 and / or the second coil 1242 may have 4 to 6 radial turns and 17 to 20 axial layers.

[0056] In some embodiments, in order to make the DC impedance of the single coil (first coil 1241 or second coil 1242) within the range of 16Ω±1.6Ω and to make the number of radial coils an even number, the relationship between the wire diameter, the number of radial turns, the number of axial layers, and the DC impedance of the exemplary parallel connected single coils (first coil 1241 and / or second coil 1242) is shown in FIG. 2. For example, the parallel connected single coils (first coil 1241 and / or second coil 1242) may have a wire diameter of 0.08 mm, a number of radial turns of 6, a number of axial layers of 17, and a corresponding DC impedance of 16.16Ω. Also, for example, the parallel connected single coils (first coil 1241 and / or second coil 1242) may have a wire diameter of 0.07 mm, a number of radial turns of 4, a number of axial layers of 20, and a corresponding DC impedance of 16.27Ω.

[0057] [Table 2]

[0058] In some embodiments, as shown in FIG. 4 or FIG. 6, the coil 124 is fitted around an axis parallel to the vibration direction on the outside of the magnet assembly 1231, and the magnetic flux conductive cover 1232 is fitted around the axis on the outside of the coil 124, and a magnetic gap A1 is formed between the coil 124 and the magnet assembly 1231. The magnetic gap A1 is a gap formed between the inner wall of the coil 124 and the outer wall of the magnet 1233 in the magnet assembly 1231. If the magnetic gap A1 is too large, the magnetic field strength is reduced, and if the magnetic gap A1 is too small, it is difficult to realize the machining process. Therefore, in some embodiments, in order to balance the magnetic field strength and the realization of the machining process, the width of the magnetic gap A1 along the radial direction may be within a range of 0.25 mm to 0.35 mm. For example, the magnetic gap A1 may be within a range of 0.27 mm to 0.33 mm. For example, the magnetic gap A1 may be within a range of 0.29 mm to 0.31 mm. Further, for example, the magnetic gap A1 between the coil 124 and the magnet assembly 1231 may be 0.3 mm. In some embodiments, on the premise of satisfying the width requirement of the magnetic gap A1, after selecting an appropriate size of the magnet 1233, the radial elasticity of the vibration transmission sheet (e.g., the first vibration transmission sheet 125 and the second vibration transmission sheet 126) may be designed to obtain the necessary condition for resisting the attractive force of the magnet 1233.

[0059] In some embodiments, in order to avoid magnetic saturation of the magnetic flux conducting cover 1232 being detrimental to the improvement of the magnetic field strength, the thickness of the magnetic flux conducting cover 1232 along the radial direction of the energy conversion device 12 should not be too thin. In some embodiments, the thickness of the magnetic flux conducting cover 1232 along the radial direction of the energy conversion device 12 may be 0.3 mm or more. If the magnetic flux conducting cover 1232 is too thick, the thickness of the energy conversion device 12 increases, so the thickness of the magnetic flux conducting cover 1232 should not be too thick. Therefore, in order to achieve both weight reduction and avoidance of magnetic saturation, the thickness of the magnetic flux conducting cover 1232 along the radial direction of the energy conversion device 12 may be in the range of 0.3 mm to 1 mm. For example, the thickness of the magnetic flux conducting cover 1232 may be in the range of 0.4 mm to 0.9 mm. For example, the thickness of the magnetic flux conducting cover 1232 may be in the range of 0.5 mm to 0.8 mm. In some embodiments, as shown in FIG. 7(a), the magnetic flux conducting cover 1232 may have a lightening structure 1232a to further reduce the mass of the energy conversion device 12 (further reduce the mass of the speaker 10). The lightening structure 1232a may include a lightening groove, a lightening hole, etc., formed in the magnetic flux conducting cover 1232. The lightening groove or the lightening hole may be a removal structure of any shape or configuration. For example, the lightening groove may be a through groove or a recessed groove having any cross section on the magnetic flux conducting cover 1232. Also, for example, the lightening groove may be an annular groove formed on the inner wall of the magnetic flux conducting cover 1232. In some embodiments, the lightening groove may be a rectangular through groove that penetrates the side wall of the magnetic flux conducting cover 1232 and extends to one end surface along the vibration direction of the magnetic flux conducting cover 1232. FIG. 7(c) is a partial schematic view of a cylindrical magnetic flux conducting cover 1232 according to some embodiments of the present application. Fig. 7(d) is a schematic diagram of a cup-shaped magnetic flux conducting cover 1232 according to some embodiments of the present application. As shown in Fig. 7(c), the lightening structure 1232a may include a lightening hole formed in a side wall of the cylindrical magnetic flux conducting cover 1232. As shown in Fig. 7(d), the lightening structure 1232a may include a lightening hole formed in a side wall and / or a bottom of the cup-shaped magnetic flux conducting cover 1232.

[0060] FIG. 8 is a comparison diagram of frequency response curves when a groove is formed in the magnetic flux conductive cover 1232 and when no groove is formed. As shown in FIG. 8, the horizontal axis represents frequency (Hz), and the vertical axis represents frequency response (dB), where curve 81 is the frequency response curve of the energy conversion device 12 when no groove is formed, and curve 82 is the frequency response curve of the energy conversion device 12 when a groove is formed. As shown in FIG. 8, the frequency corresponding to the resonance peak of curve 82 is higher than the frequency corresponding to the resonance peak of curve 81, so that after the groove is formed, the mass of the magnetic flux conductive cover 1232 is reduced, and the mass of the energy conversion device 12 is reduced, thereby increasing the resonance frequency of the energy conversion device 12. In addition, after the resonance frequency (about 100 Hz), the frequency response of the energy conversion device 12 when a groove is formed is higher than the frequency response of the energy conversion device 12 when no groove is formed at the same frequency, improving the sound quality of the energy conversion device 12.

[0061] In some embodiments, the outer diameter shape of the magnetic flux conducting cover of the magnetic flux conducting cover 1232 may be rectangular, elliptical, circular, racetrack, polygonal, etc. For example, as shown in FIG. 7(a), the outer diameter shape of the magnetic flux conducting cover of the magnetic flux conducting cover 1232 may be racetrack-shaped, and the equivalent rectangle corresponding to the racetrack shape may have a length less than 20 mm and a width less than 12 mm. For example, the equivalent rectangle corresponding to the magnetic flux conducting cover 1232 has a length and a width of 18.1 and 10.1 mm, respectively. The racetrack shape described herein is typically a closed ring formed by connecting the ends of two arcuate portions and the ends of two straight portions, respectively. For example, the racetrack shape may be a rounded rectangle, i.e., all four right angles of the rectangle may be replaced with rounded corners. The length / width of the equivalent rectangle referred to herein is the length / width of the rectangle corresponding to the racetrack shape (i.e., the shape in which the four rounded corners of the racetrack shape are replaced with right angles).

[0062] In some embodiments, the magnet assembly 1231 may include a magnet 1233 and a magnetic flux conducting plate installed on one side of the magnet 1233 in the vibration direction of the energy conversion device 12. If the magnetic flux conducting plate is too thin, it is easy to be magnetically saturated and the magnetic field strength in the coil is accordingly reduced, and if the magnetic flux conducting plate is too thick, due to the limitation of the volume of the entire magnet assembly 1231, the magnet 1233 is likely to be too thin and the generated magnetic field strength is too low. Therefore, in order to improve the magnetic field strength and avoid magnetic saturation, the ratio of the thickness of the magnetic flux conducting plate to the thickness of the magnet 1233 may be in the range of 0.05 to 0.35. For example, the ratio of the thickness of the magnetic flux conducting plate to the thickness of the magnet 1233 may be in the range of 0.15 to 0.3. In some embodiments, the magnetic flux conducting plate may include a first magnetic flux conducting plate 1234 and a second magnetic flux conducting plate 1235. The first magnetic flux conducting plate 1234 is located on one side of the magnet 1233 in the vibration direction of the energy conversion device 12, and the second magnetic flux conducting plate 1235 is located on the other side of the magnet 1233 in the vibration direction of the energy conversion device 12. The ratio of the thickness of the first magnetic flux conducting plate 1234 or the second magnetic flux conducting plate 1235 (hereinafter, abbreviated as magnetic flux conducting plate) to the thickness of the magnet 1233 may be in the range of 0.05 to 0.35. In some embodiments, the thickness of the magnetic flux conducting plate (the first magnetic flux conducting plate 1234 or the second magnetic flux conducting plate 1235) may be in the range of 0.5 mm to 1 mm to improve the magnetic field strength and avoid magnetic saturation. For example, the thickness of the magnetic flux conducting plate (the first magnetic flux conducting plate 1234 or the second magnetic flux conducting plate 1235) may be in the range of 0.6 mm to 0.7 mm.

[0063] In some embodiments, holes may be formed in the magnet 1233 and / or the magnetic flux conducting plate (the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235) to facilitate assembly and positioning of the magnet 1233 and the magnetic flux conducting plate (the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235) and to reduce the mass of the energy conversion device 12 (further reducing the mass of the entire acoustic output device 100). For example, as shown in FIG. 7(a), a first hole 1233a may be provided in the magnet 1233 and a second hole 1234a may be provided in the magnetic flux conducting plate (the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235) to facilitate assembly and positioning of the magnet 1233 and the magnetic flux conducting plate (the first magnetic flux conducting plate 1234 and / or the second magnetic flux conducting plate 1235), and the second hole 1234a and the first hole 1233a may be provided correspondingly.

[0064] In some embodiments, in order to improve the accuracy of assembly, the number of the second holes 1234a on the magnetic flux conducting plate may be at least two. Correspondingly, the number of the first holes 1233a on the magnet 1233 may also be at least two, each corresponding to a second hole 1234a. FIG. 9(a)-FIG. 9(c) are schematic plan views of magnetic flux conducting plates according to various embodiments herein. As shown in FIG. 9(a), the magnetic flux conducting plate is a rounded rectangular structure, and the two second holes 1234a are disposed along the longitudinal direction (shown in FIG. 9(a)) of the magnetic flux conducting plate. In some embodiments, the two second holes 1234a are disposed on the centerline along the longitudinal direction of the magnetic flux conducting plate. As shown in FIG. 9(b), the magnetic flux conducting plate is a rounded rectangular structure, and the two second holes 1234a are disposed along the diagonal direction of the magnetic flux conducting plate. As shown in FIG. 9(c), the magnetic flux conducting plate has a rectangular structure with rounded corners, and second holes 1234a are provided in the vicinity of each of the four rounded corners.

[0065] FIG. 10 is a comparison diagram of frequency response curves when the magnetic flux conducting plate has holes and when it does not have holes. FIG. 11 is a comparison diagram of longitudinal BL value curves when the magnetic flux conducting plate has holes and when it does not have holes. In FIG. 10, curve 101 is a frequency response curve when the magnetic flux conducting plate has no holes, curve 102 is a frequency response curve when two holes are provided on the longitudinal center line of the magnetic flux conducting plate (as shown in FIG. 9(a)), curve 103 is a frequency response curve when two holes are provided diagonally in the magnetic flux conducting plate (as shown in FIG. 9(b)), and curve 104 is a frequency response curve when four holes are provided diagonally in the magnetic flux conducting plate (as shown in FIG. 9(c)). 10, comparing curve 102 with curve 103, it can be seen that the frequency response curve when two holes are provided on the center line along the longitudinal direction of the magnetic flux conducting plate is almost the same as the frequency response curve when two holes are provided along the diagonal line, and comparing curve 103 with curve 104, it can be seen that similarly, holes are formed on the diagonal line, and as the number of holes increases, the frequency response slightly decreases, the decrease being within the range of about 0.5 dB. Comparing curve 101 with the other curves (curve 102, 103, or 104), it can be seen that the frequency response slightly decreases, the decrease being about 0.5 dB, compared to when no holes are formed in the magnetic flux conducting plate, and therefore the effect of the holes on the frequency response is not large. However, from the standpoint of reducing weight and ease of assembly and positioning, forming holes reduces the mass of the energy conversion device 12 and facilitates assembly and positioning of the magnets 1233 and the magnetic flux conducting plates (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235).

[0066] In Fig. 11, curve 1111 is the BL value curve when no holes are formed in the flux conducting plate, curve 1112 is the BL value curve when two holes are provided on the longitudinal center line of the flux conducting plate (as shown in Fig. 9(a)), curve 1113 is the BL value curve when two holes are provided along a diagonal line of the flux conducting plate (as shown in Fig. 9(b)), and curve 1114 is the BL value curve when four holes are provided along a diagonal line of the flux conducting plate (as shown in Fig. 9(c)). The BL value reflects the electromagnetic properties and is the product of the magnetic field strength and the length of the coil wire. As shown in FIG. 11, when curve 1112 is compared with curve 1113, it is found that the BL value curve when two holes are formed on the center line along the longitudinal direction of the magnetic flux conducting plate and the BL value curve when two holes are formed along the diagonal line are almost the same, and when curve 1113 is compared with curve 1114, it is found that the BL value is slightly decreased as the number of holes formed increases when holes are formed on the diagonal line. When curve 1111 is compared with the other curves (curve 1112, 1113, or 1114), it is found that the BL value is slightly decreased compared to the case where no holes are formed in the magnetic flux conducting plate, and the decrease is within the range of approximately 0.05 T·m, so that the effect of the holes on the BL value is not large. However, from the viewpoints of weight reduction and ease of assembly and positioning, by forming the holes, the mass of the energy conversion device 12 is reduced and the assembly and positioning of the magnet 1233 and the magnetic flux conducting plate (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) is facilitated.

[0067] In some embodiments, the location of the second holes 1234a on the magnetic flux conducting plate has a significant effect on the BL value of the energy conversion device 12. Taking the example of two second holes 1234a being located on the center line along the longitudinal direction of the magnetic flux conducting plate, FIG. 12 is a comparison diagram of BL value curves when the distance from the second holes on the magnetic flux conducting plate to the center of the magnetic flux conducting plate is different. As shown in FIG. 12, the curve 1211 is the BL value curve when the second holes 1234a are 5 mm away from the center of the magnetic flux conducting plate, the curve 1212 is the BL value curve when the second holes 1234a are 5.5 mm away from the center of the magnetic flux conducting plate, the curve 1213 is the BL value curve when the second holes 1234a are 6 mm away from the center of the magnetic flux conducting plate, and the curve 1214 is the BL value curve when the second holes 1234a are 6.5 mm away from the center of the magnetic flux conducting plate. At the same coil offset amount (for example, the coil offset amount is 0 mm), the curve 1211, the curve 1212, the curve 1213, and the curve 1214 fall in order, and the curve 1214 is obviously lower than the other three curves. Here, the center of the magnetic flux conducting plate is the geometric center of the magnetic flux conducting plate. As can be seen from FIG. 12, the farther the second hole 1234a is from the center of the magnetic flux conducting plate, the closer it is to the edge of the magnetic flux conducting plate, and the BL value of the energy conversion device 12 is significantly reduced, so the second hole 1234a should be installed as close to the edge of the magnetic flux conducting plate as possible. Note that the distance from the second hole 1234a to the center of the magnetic flux conducting plate is the distance between the center of the second hole and the geometric center of the magnetic flux conducting plate. In some embodiments, in order to improve the BL value of the energy conversion device 12, the ratio of the formation area of ​​the second hole 1234a to the surface area of ​​the magnetic flux conducting plate in which the second hole 1234a is located is less than 36%, and the formation shape and formation position of the second hole 1234a are not limited.9(a), the line connecting the hole center W2 of the second hole 1234a and the geometric center W1 of the magnetic flux conducting plate extends to the edge of the magnetic flux conducting plate to form a straight line LA, the intersection point between the straight line LA and the edge of the magnetic flux conducting plate is point B, the intersection point between the straight line LA and the edge of the second hole 1234a close to point B is point C, and the distance between the edge of the second hole 1234a and the edge of the magnetic flux conducting plate is the distance between point B and point C on the straight line LA. In some embodiments, the distance from the edge of the second hole 1234a to the edge of the magnetic flux conducting plate may be greater than 0.2 mm to prevent the second hole from being too close to the edge, which reduces the structural strength, and to reduce the effect of the second hole on the magnetic field strength and ensure that the sensitivity of the speaker is not significantly reduced.

[0068] FIG. 13 is a comparison diagram of frequency response curves when the diameter of the second hole 1234a is different. As shown in FIG. 13, a curve 1311 is a frequency response curve when the diameter of the second hole 1234a is 1 mm, a curve 1312 is a frequency response curve when the diameter of the second hole 1234a is 1.5 mm, and a curve 1313 is a frequency response curve when the diameter of the second hole 1234a is 2 mm. As the hole diameter of the second hole 1234a increases, the frequency response of the energy conversion device 12 decreases, and the frequency response of the energy conversion device 12 decreases by about 0.5 dB for every 0.5 mm increase in diameter. FIG. 14(a) is a comparison diagram of BL value curves when the diameter of the second hole 1234a is different. As shown in FIG. 14(a), curve 141 is a BL value curve when the diameter of the second hole 1234a is 1 mm, curve 142 is a BL value curve when the diameter of the second hole 1234a is 1.5 mm, and curve 143 is a BL value curve when the diameter of the second hole 1234a is 2 mm. As the hole diameter of the second hole 1234a becomes larger, the BL value becomes smaller. Therefore, the larger the diameter of the second hole 1234a, the smaller the frequency response and the BL value. However, due to the influence of processing accuracy and structural strength, the diameter of the second hole 1234a should not be too small. Therefore, in order to avoid the second hole 1234a being too small and the corresponding positioning pillar being too thin, so as to avoid the positioning pillar being too thin and the structural strength being insufficient, and the requirement for processing accuracy being too high, and to avoid the diameter being too large and the frequency response and BL value being small, the diameter of the second hole 1234a may be in the range of 1.5mm to 2.5mm. For example, the diameter of the second hole 1234a may be in the range of 1.8mm to 2.3mm. In some embodiments, in order to balance the magnetic field strength and the sensitivity of the energy conversion device 12, the ratio of the formation area of ​​the second hole 1234a to the surface area of ​​the magnetic flux conducting plate where the second hole 1234a is located is less than 36%.

[0069] In some embodiments, by setting the number of coils 124 along the radial direction of the energy conversion device 12 to an even number, the inlet and outlet of the first coil 1241 or the second coil 1242 are at the same position of the magnetic flux conducting cover 1232, so that the inner wall of the magnetic flux conducting cover 1232 is in close contact with the outer wall of the coil 124, thereby reducing the mass of the energy conversion device 12 (and further reducing the mass of the speaker 10). Also, by making the shape of the coil 124 (the first coil 1241 and the second coil 1242) "elongated", and by selecting appropriate parameters of the coil 124, both the inner diameter of the magnetic flux conducting cover 1232 can be made small, thereby reducing the mass of the energy conversion device 12 (and further reducing the mass of the speaker 10). In some embodiments, providing a lightening groove in the magnetic flux conducting cover 1232 or forming holes in the magnets 1233 and / or the magnetic flux conducting plates (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) can both reduce the mass of the energy conversion device 12 (and thus the mass of the loudspeaker 10). In some embodiments, the mass m of the loudspeaker 10 after weight reduction may be in the range of 2 g to 5 g. For example, the mass m of the loudspeaker 10 may be in the range of 3.8 g to 4.5 g.

[0070] FIG. 14(b) is a comparison diagram of acceleration curves when the mass of the energy conversion device 12 according to some embodiments of the present specification is in the range of 2g to 5g. Scheme A to Scheme I show different embodiments in which the mass of the energy conversion device 12 is in the range of 2g to 5g, in the cases of different wire diameters of the coils (first coil and second coil), different radial turns and axial layers, different products of the radial turns and axial layers, different connection methods of the coils (series connection or parallel connection), etc. As shown in FIG. 14(b), the energy conversion device 12 after weight reduction (the mass of the energy conversion device 12 is in the range of 2g to 5g) shown in some embodiments of the present specification has an acceleration range of 70dB to 110dB at 1kHz under the excitation of the test voltage. The method of measuring the acceleration curve shown in FIG. 14(b) is to excite the energy conversion device 12 according to the embodiment of the present specification to vibrate with a test voltage, measure the displacement of the vibration panel 13 caused by the driving of the energy conversion device 12 by a laser test, and then normalize the displacement by data processing, i.e., divide the displacement of the corresponding frequency band by the corresponding test voltage, and then normalize the displacement by 1 mm / s. 2 The acceleration dB value is obtained by calculating the ratio of the acceleration dB value to the acceleration dB value. In some embodiments, the sound quality of the speaker 10 can be improved by adjusting the acceleration range to an appropriate range and improving the sensitivity of the energy conversion device 12. Even if the amplitude of the BL value curve drops after weight reduction, the frequency response acceleration is improved. The acceleration curve shown in FIG. 14(b) is obtained by measuring the vibration acceleration of the diaphragm panel 13 with the fixing assembly 20 fixed.

[0071] In some embodiments, the vibration transmission sheet 122 may be connected between the magnetic flux conductive cover 1232 and the magnet assembly 1231, and may elastically support the magnet assembly 1231. In some embodiments, the vibration transmission sheet 122 may include a first vibration transmission sheet 125 and a second vibration transmission sheet 126. As shown in FIG. 7(a), the first vibration transmission sheet 125 or the second vibration transmission sheet 126 (hereinafter, abbreviated as the vibration transmission sheet 122) may include an edge region 1253, a central region 1252, and a plurality of support rods 1251 connecting the edge region 1253 and the central region 1252. In some embodiments, the central region 1252 of the vibration transmission sheet 122 (e.g., the first vibration transmission sheet 125 or the second vibration transmission sheet 126) may be connected to the magnet assembly 1231. For example, the central region 1252 of the first vibration transmission sheet 125 is connected to the first magnetic flux conducting plate 1234 of the magnet assembly 1231, and the central region 1262 of the second vibration transmission sheet 126 is connected to the second magnetic flux conducting plate 1235 of the magnet assembly 1231. In some embodiments, a through hole (shown in FIG. 16(a) and FIG. 16(b)) may be formed in the central region 1252, and a boss may be provided on the side of the magnetic flux conducting plate facing the central region 1252, so that the boss and the through hole cooperate to realize the connection and fixation. In some embodiments, the boss may be a hot melt post, which is inserted into the through hole and then can fix the central region 1252 to the magnetic flux conducting plate by melting and deformation. In some embodiments, the outer contour of the edge region 1253 of the vibration transmission sheet may be racetrack-shaped, rectangular, elliptical, circular, etc. Compared to using a single vibration transmission sheet, a dual vibration transmission sheet (i.e., the vibration transmission sheet 122 includes a first vibration transmission sheet 125 and a second vibration transmission sheet 126) can significantly improve the number of failure cycles, and the elastic support of the magnet assembly 1231 by the first vibration transmission sheet 125 and the second vibration transmission sheet 126 reduces the oscillation range of the movable parts in the energy conversion device 12.

[0072] In some embodiments, the plurality of support rods 1251 of the vibration transmission sheet 122 may have a serpentine structure so that the vibration transmission sheet has a predetermined elastic modulus. Figures 15(a) to 15(c) are schematic diagrams of the vibration transmission sheet 122 according to some embodiments of the present specification, and Figures 16(a) and 16(b) are schematic diagrams of the vibration transmission sheet 122 according to some embodiments of the present specification. Figures 15(a) to 15(c), 16(a) and 16(b) show several embodiments of the vibration transmission sheet and several embodiments of the support rods. In some embodiments, the support rod 1251 of the vibration transmission sheet uses a multiple-serpentine structure as shown in Figures 15(a) to 15(c), 16(a) and 16(b), with both ends connected to the edge region 1253 and the central region 1252 respectively, thereby making the vibration transmission sheet have a predetermined elastic modulus and preventing or reducing rotational and / or swinging movement between the coil and the movable member of the magnetic circuit system 123.

[0073] 16(a) and 16(b), in some embodiments, a through hole 1252a for inserting a boss provided on a magnetic flux conducting plate (the first magnetic flux conducting plate 1234 or the second magnetic flux conducting plate 1235) is provided in the central region 1252 of the vibration transmitting sheet 122, so that the boss and the through hole 1252a cooperate to realize connection and fixation. Exemplary connection methods may include hot melt, bolts, etc.

[0074] To resist the magnetic attraction force of the magnet assembly 1231 and avoid the occurrence of magnet offset in the energy conversion device 12, the stiffness in any direction in a plane perpendicular to the vibration direction of the vibration transmitting sheet 122 (hereinafter, abbreviated as radial direction) may be greater than a stiffness threshold. For example, based on the width of the magnetic gap A1 and the magnetic attraction force between the magnet assembly 1231 and the magnetic flux conductive cover 1232, the equivalent stiffness in the radial direction of the vibration transmitting sheet 122 may be 4.7×10 4 For example, the equivalent stiffness of the vibration transmission sheet 122 in the radial direction can be determined to be greater than 6.4×10 4The elastic vibration transmission sheet 122 may have a stiffness of more than N / m. By optimizing the stiffness in the longitudinal direction and the width direction in the plane perpendicular to the vibration direction of the elastic vibration transmission sheet 122, it is possible to resist the magnetic attraction force of the magnet assembly 1231 and to prevent the magnet offset from occurring in the energy conversion device 12, that is, to prevent the coil from colliding with the movable member of the magnetic circuit system 123.

[0075] The energy conversion device 12 according to the present specification may include at least one vibration transmission sheet connected between the magnet assembly 1231 and the magnetic flux conductive cover 1232. The equivalent stiffness in the radial direction of the at least one vibration transmission sheet is 4.7×10 4 N / m. For example, the energy conversion device 12 may include only at least one vibration transmission sheet 122. Also, for example, the energy conversion device 12 may include only at least two vibration transmission sheets 122, i.e., a first vibration transmission sheet 125 and a second vibration transmission sheet 126. The equivalent stiffness in the radial direction of each of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 is 4.7×10 4 It may be greater than N / m.

[0076] In some embodiments, the relevant dimension data of the vibration transmitting sheet 122 can be determined based on the requirement for equivalent stiffness in the radial direction of the vibration transmitting sheet 122. In some embodiments, the ratio of the distance between the start point and the end point of the support rod 1251 along the longitudinal direction of the vibration transmitting sheet 122 to the length of the support rod 1251 itself may be in the range of 0 to 1.2. The distance along the longitudinal direction of the vibration transmitting sheet 122 between the start point and the end point of the support rod 1251 is the distance along the longitudinal direction of the vibration transmitting sheet 122 between the connection point of the support rod 1251 and the central region 1252 of the vibration transmitting sheet and the connection point of the support rod 1251 and the edge region 1253 of the vibration transmitting sheet. For example, as shown in FIG. 16(b), the ratio of the distance SE between the start point S and the end point E of the support rod 1251 along the longitudinal direction of the vibration transmitting sheet 122 to the total length of the curved support rod 1251 may be in the range of 0.7 to 0.85. In some embodiments, the ratio of the distance between the start point and the end point of the support rod 1251 along the width direction of the vibration transmission sheet 122 to the length of the support rod 1251 itself may be in the range of 0 to 0.5. The distance between the start point and the end point of the support rod 1251 along the width direction of the vibration transmission sheet 122 is the distance along the width direction of the vibration transmission sheet 122 between the connection point of the support rod 1251 and the central region 1252 of the vibration transmission sheet and the connection point of the support rod 1251 and the edge region 1253 of the vibration transmission sheet. For example, as shown in FIG. 16(b), the ratio of the distance S'E' between the start point S and the end point E of the support rod 1251 along the width direction of the vibration transmission sheet 122 to the total length of the curved support rod 1251 may be in the range of 0.15 to 0.35.

[0077] In some embodiments, the length of the support rod 1251 may be in the range of 7 mm to 25 mm. In some embodiments, the thickness of the support rod along the axial direction of the energy conversion device 12 (i.e., the thickness of the vibration transmission sheet) may be in the range of 0.1 mm to 0.2 mm. In some embodiments, the ratio of the thickness of the vibration transmission sheet along the axial direction of the energy conversion device 12 to the width of a plane along the radial direction of the energy conversion device 12 of any one of the support rods 1251 may be in the range of 0.16 to 0.75. Exemplary ranges of the thickness-to-width ratio may include 0.2 to 0.7, 0.26 to 0.65, 0.3 to 0.6, 0.36 to 0.55, or 0.4 to 0.5, etc. In some embodiments, the thickness of the first vibration transmission sheet 125 may be in the range of 0.1 mm to 0.2 mm, and the width of the support rod 1251 may be in the range of 0.25 mm to 0.5 mm. For example, the thickness of the first vibration transmitting sheet 125 may be within the range of 0.1 mm to 0.15 mm, and the width of the support rod 1251 may be within the range of 0.4 mm to 0.48 mm.

[0078] In some embodiments, the speaker 10 may include an air conduction speaker and a bone conduction speaker (for example, as shown in FIG. 4 or FIG. 5(a)). In some embodiments, the crossover frequency between the bone conduction and the air conduction may be set in a mid-low frequency range, for example, within a range of 400Hz to 500Hz, and a sound higher than the crossover frequency is generated by the bone conduction speaker, and a sound lower than the crossover frequency is generated by the air conduction speaker. In this way, the bone conduction speaker can be prevented from vibrating in the low frequency band and causing the user to feel significant vibration. In addition, the bone conduction speaker has a relatively flat frequency response curve at a portion slightly away from the resonant peak frequency, and the output distortion of the corresponding frequency band in this portion is relatively small, so that the resonant peak frequency of the bone conduction speaker may be set to be lower than the crossover frequency and to maintain a certain distance from the crossover frequency. In some embodiments, the resonant peak frequency of the energy conversion device 12 may be lower than 300Hz.

[0079] In some embodiments, since the resonant peak frequency of the energy conversion device 12 is less than 300 Hz, the range of the ratio of the total axial (parallel to the vibration direction) elastic coefficient k of the vibration transmission sheet 122 to the mass m of the energy conversion device 12 may be set by the following formula:

number

[0080] In some embodiments, the mass of the energy conversion device 12 may include the sum of the masses of the magnetic flux conducting cover 1232, the coil 124 and the housing 11, or may include the sum of the masses of the air conducting speaker 16, the magnetic flux conducting cover 1232, the coil 124 and the housing 11. The elastic modulus k has units of N / m (Newtons / meter) and the mass m has units of g (grams).

[0081] In some embodiments, in order to reduce the overall volume and mass of the device and improve sound quality, the mass m of the energy conversion device 12 may be in the range of 2 g to 5 g. For example, the mass of the energy conversion device 12 may be in the range of 2.2 g to 4.8 g. Also, for example, the mass of the energy conversion device 12 may be in the range of 3.8 g to 4.5 g.

[0082] In some embodiments, based on the mass range of the energy conversion device 12 and the range of the ratio of the total axial elasticity coefficient k of the vibration transmission sheet 122 to the mass m of the energy conversion device 12, it can be determined that the total axial elasticity coefficient k of the vibration transmission sheet 122 is less than 18000 N / m. In some embodiments, the vibration transmission sheet 122 includes a first vibration transmission sheet 125 and a second vibration transmission sheet 126 connected in parallel as shown in FIG. 4. In some embodiments, the axial elasticity coefficient k0 of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 may be the same and both may be less than 9000 N / m. In some embodiments, the axial elasticity coefficient k0 of each of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 may be different, but the total axial elasticity coefficient k provided by both of them together is less than 18000 N / m.

[0083] Therefore, by adjusting the mass range of the mass block connected to the dual vibration transmission sheet consisting of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 and / or the elastic coefficient of the dual vibration transmission sheet, it is possible to realize that the bone conduction resonance peak frequency does not exceed 300 Hz. Here, the mass of the mass block described in this specification is the mass of all members that need to be pressed by the dual vibration transmission sheet. For example, in the embodiment shown in FIG. 2(a), the mass of the mass block is the total mass of the coil 124, the magnetic flux conductive cover 1232, the bracket 121, the vibration panel 13, and the vibration damping sheet 14. Also, for example, in the embodiment shown in FIG. 3, the mass of the mass block is the total mass of the coil 124, the magnetic flux conductive cover 1232, the vibration panel 13, and the housing 11. Also, in the embodiment of the bone air conduction speaker, the mass of the mass block further includes the mass of the air conduction speaker. In some embodiments, the mass of the mass block may further include the mass of other necessary connecting members.

[0084] Therefore, by adjusting the mass range of the mass block connected to the dual vibration transmission sheet consisting of the first vibration transmission sheet 125 and the second vibration transmission sheet 126 and / or the elastic coefficient of the dual vibration transmission sheet, it is possible to realize that the bone conduction resonance peak frequency does not exceed 300 Hz. Here, the mass of the mass block described in this specification is the mass of all members that need to be pressed by the dual vibration transmission sheet. For example, in the embodiment shown in FIG. 2(a), the mass of the mass block is the total mass of the coil 124, the magnetic flux conductive cover 1232, the bracket 121, the vibration panel 13, and the vibration damping sheet 14. Also, for example, in the embodiment shown in FIG. 3, the mass of the mass block is the total mass of the coil 124, the magnetic flux conductive cover 1232, the vibration panel 13, and the housing 11. Also, in the embodiment of the bone air conduction speaker, the mass of the mass block further includes the mass of the air conduction speaker. Also, the mass of the mass block may further include the mass of other necessary connecting members.

[0085] 17(a) to 17(g) are schematic diagrams of a magnetic circuit system 123 of a Halbach array type according to a number of embodiments of the present specification. Note that FIG. 17(a) to 17(g) show a central cross section of the magnetic circuit system 123, and are the right half of a two-dimensional axially symmetric figure. As shown in FIG. 4, FIG. 6, and FIG. 17(a) to FIG. 17(g), the energy conversion device 12 may include a magnetic circuit system 123 and a coil 124. The magnetic circuit system 123 may include a magnet assembly 1231 and a magnetic flux conductive cover 1232. The coil 124 may be fitted to the outside of the magnet assembly 1231 around an axis parallel to the vibration direction, and the magnetic flux conductive cover 1232 may be fitted to the outside of the coil 124 around the axis. In some embodiments, at least one of the magnet 1233, the magnetic flux conducting plate, and the magnetic flux conducting cover 1232 included in the magnet assembly 1231 may include multiple magnetic parts with different magnetization directions. In some embodiments, the magnet assembly 1231 and / or the magnetic flux conducting cover 1232 may include multiple magnetic parts (e.g., magnets) with different magnetization directions. The multiple magnetic parts with different magnetization directions may form a Halbach array (e.g., as shown in Figures 17(a)-17(g)). The particular array arrangement allows the magnetic field to be concentrated on one side of the magnetic assembly 1231, thereby improving the magnetic field strength in the coil 124.

[0086] In some embodiments, the magnet 1233, the magnetic flux conducting plate or the magnetic flux conducting cover 1232 may have an arrangement of magnetic parts with different magnetization directions. In some embodiments, the magnetization directions of the magnetic parts rotate in a clockwise or counterclockwise direction on a surface parallel to the vibration direction of the energy conversion device 12. As shown in FIG. 17(a), the magnet 1233 and the magnetic flux conducting plate (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) may not have a magnetic part arrangement, and the magnetic flux conducting cover 1232 may include three layers of magnetic parts arranged along the axial direction, and the magnetization directions of the three layers of magnetic parts are radially outward, axially downward and radially inward from top to bottom, respectively. 17(b), the magnetic flux conducting cover 1232 and the magnet 1233 may not have a magnetic portion arrangement, and the magnetic flux conducting plate (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) may include four magnetic portions arranged along a radial direction, and the top magnetic portion and the bottom magnetic portion each include two magnetic portions arranged along a radial direction, and the magnetization directions of the two magnetic portions of the top magnetic portion are axially upward and radially outward from left to right, respectively, and the magnetization directions of the two magnetic portions of the bottom magnetic portion are axially upward and radially inward from left to right, respectively. In some embodiments, the magnetic flux conducting plate (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) and the magnetic flux conducting cover 1232 may both have a magnetic portion arrangement. As shown in Figure 17(c), the magnetic portion arrangement of the magnetic flux conducting plates (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) is similar to the magnetic portion arrangement of the magnetic flux conducting plates shown in Figure 17(b) and the magnetic portion arrangement of the magnetic flux conducting cover 1232 is similar to the magnetic portion arrangement of the magnetic flux conducting cover 1232 shown in Figure 17(a). In some embodiments, compared to a three-layer magnetic portion arrangement, the magnets 1233, the magnetic flux conducting plates and / or the magnetic flux conducting cover 1232 may have more magnetic portion arrangements.As shown in FIG. 17(d), the magnet 1233 and the magnetic flux conducting plates (first magnetic flux conducting plate 1234 and / or second magnetic flux conducting plate 1235) may not have a magnetic portion arrangement, and the magnetic flux conducting cover 1232 may include five layers of magnetic portions arranged along the axial direction, and the magnetization directions of the five layers of magnetic portions are axially upward, radially outward, axially downward, radially inward, and axially upward, respectively, from top to bottom. In some embodiments, the magnet 1233 may be a hollow ring structure. As shown in FIG. 17(e), the magnet 1233 may include three layers of magnetic portions arranged along the axial direction, and the magnetization directions of the three layers of magnetic portions are radially outward, axially upward, and radially inward, respectively, from top to bottom. As shown in FIG. 17(f), the magnet 1233 may include five layers of magnetic portions arranged along the axial direction, and the magnetization directions of the five layers of magnetic portions are axially downward, radially outward, axially upward, radially inward, and axially downward, respectively, from top to bottom. 17(g), the magnet 1233 may include three layers of magnetic parts arranged along the axial direction, and the magnetization directions of the three layers of magnetic parts are radially outward, axially upward, and radially inward, respectively, from top to bottom, and the magnetic flux conducting cover 1232 may include three layers of magnetic parts arranged along the axial direction, and the magnetization directions of the three layers of magnetic parts are radially outward, axially downward, and radially inward, respectively, from top to bottom. In some embodiments, the magnetization directions of at least two adjacent magnetic parts of the plurality of magnetic parts may be perpendicular to each other.

[0087] FIG. 18 is a comparison diagram of BL value curves when the magnetic circuit system 123 has different magnetic part arrangements. In FIG. 18, curve 181 is a BL value curve when the magnetic circuit system 123 does not have a magnetic part arrangement, and curves 182 to 188 are BL value curves of the magnetic circuit system 123 when the magnetic circuit system 123 has the magnetic part arrangements shown in FIG. 17(a) to FIG. 17(g), respectively. As can be seen from FIG. 18, the magnetic field strength is improved when the magnetic flux conducting cover and / or the magnet assembly has a magnetic part arrangement compared to when the magnetic part arrangement is not installed. When the magnetic flux conducting cover has a magnetic part arrangement, the magnetic field strength is improved more significantly, by about 12%, compared to when the magnetic part arrangement is not installed. By installing the magnet 1233 as a hollow annular magnetic part arrangement, the magnetic field strength is still improved by about 6% compared to when the magnetic part arrangement is not installed.

[0088] Possible beneficial effects of the embodiments of the present specification include, but are not limited to, the following (1) to (10): (1) By setting the number of coils of the coil 124 along the radial direction of the energy conversion device 12 to an even number, the inlet and outlet of the first coil 1241 or the second coil 1242 are at the same position of the magnetic flux conductive cover 1232, so that the inner wall of the magnetic flux conductive cover 1232 is in close contact with the outer wall of the coil 124, and the mass of the energy conversion device 12 (and the mass of the speaker 10) can be reduced. (2) By making the shape of the coil 124 (the first coil 1241 and the second coil 1242) "elongated" and selecting appropriate parameters of the coil 124, the inner diameter of the magnetic flux conductive cover 1232 can be reduced, thereby reducing the mass of the energy conversion device 12 (and the mass of the speaker 10). (3) Providing a lightening groove in the magnetic flux conductive cover 1232 or forming a hole in the magnet 1233 and / or the magnetic flux conductive plate (the first magnetic flux conductive plate 1234 and / or the second magnetic flux conductive plate 1235) can reduce the mass of the energy conversion device 12 (and further reduce the mass of the speaker 10). (4) By adjusting the mass of the speaker 10 and the total axial elastic modulus of the vibration transmission sheet 122, the bone conduction resonance peak frequency can be prevented from exceeding 300 Hz, and the bone conduction speaker can be prevented from vibrating in a low frequency band and causing the user to feel noticeable vibration. (5) By setting the rigidity in any direction (radial direction) in a plane perpendicular to the vibration direction of the vibration transmission sheet 122, the magnetic attraction force of the magnet assembly 1231 can be resisted and the occurrence of magnet offset in the energy conversion device 12 can be avoided. (6) By setting the ratio between the thickness of the magnetic flux conductive plate and the thickness of the magnet 1233, the magnetic field strength can be improved, magnetic saturation can be avoided, and the sensitivity of the speaker 10 can be improved. (7) By providing an arrangement of magnetic parts with different magnetization directions in at least one of the magnet 1233, the magnetic flux conductive plate and / or the magnetic flux conductive cover 1232, the magnetic field strength is improved, thereby further improving the sensitivity of the speaker 10.(8) By using a dual coil (first coil 1241 and second coil 1242), dual driving is realized and the high frequency impedance of the coil is reduced, thereby improving the sensitivity of the energy conversion device 12. (9) By fixing the dual vibration transmission sheets (i.e., the vibration transmission sheet 122 includes the first vibration transmission sheet 125 and the second vibration transmission sheet 126) to both sides of the magnet 1233, high sensitivity output is guaranteed, and the support of the dual vibration transmission sheets (i.e., the vibration transmission sheet 122 includes the first vibration transmission sheet 125 and the second vibration transmission sheet 126) ensures the stability of the vibration of the magnet 1233. (10) By the coil 124 being in close contact with the magnetic flux conductive cover 1232, the magnetic gap between the magnetic flux conductive cover 1232 and the coil 124 is reduced, so that the magnetic field is more concentrated, thereby improving the sensitivity of the energy conversion device 12.

[0089] Although the basic concept has been described above, it is clear to those skilled in the art that the above detailed disclosure is merely given as an example and does not limit the present application. Although not explicitly described in this specification, those skilled in the art can make various changes, improvements and modifications to the present application. These changes, improvements and modifications are intended to be suggested by the present application and therefore still fall within the spirit and scope of the exemplary embodiments of the present application.

[0090] Also, certain terms are used herein to describe embodiments of the present application. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic associated with at least one embodiment of the present application. Thus, it is emphasized and understood that references to "one embodiment" or "one embodiment" or "one alternative embodiment" more than once in various parts of this specification do not necessarily all refer to the same embodiment. Also, certain features, structures, or characteristics in one or more embodiments of the present application may be combined as appropriate.

[0091] Additionally, unless expressly stated in the claims, the order of enumeration of processing elements or sequences described herein, the use of alphanumeric characters, or the use of other designations, does not limit the order of procedures and methods of the present application. While the above disclosure describes through various examples what are presently believed to be various useful embodiments of the invention, it is to be understood that such details are merely illustrative and that the appended claims are not limited to only the disclosed embodiments, but on the contrary are intended to cover all modifications and equivalent combinations that are within the spirit and scope of the embodiments of the present application. For example, the system assembly described above may be implemented by a hardware device, but may also be implemented by a software-only solution, for example, by installing the described system on an existing server or mobile device.

[0092] Similarly, in the foregoing description of embodiments of the present application, various features may be grouped together in a single embodiment, figure, or description for the purpose of simplifying the description of the present disclosure and facilitating an understanding of one or more embodiments of the present invention. However, this method of disclosure should not be interpreted as reflecting an intention that the claimed subject matter requires more features than are recited in each claim. In fact, an embodiment may include fewer than all features of a single embodiment disclosed above.

[0093] In some embodiments, numbers are used to describe components and attributes, and it is to be understood that the numbers described in such embodiments are modified in some instances by the modifiers "about," "approximately," or "substantially." Unless otherwise specified, "about," "approximately," or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, all numerical parameters used in the specification and claims are approximations that may vary depending on the characteristics required for a particular embodiment. In some embodiments, the numerical parameters should be applied with the stated number of significant digits and ordinary rounding techniques. In some embodiments, the numerical ranges and parameters for determining the ranges are approximations; however, in specific embodiments, such numerical values ​​are set as precisely as possible.

[0094] All patents, patent applications, published patent applications, and other materials, such as papers, books, specifications, publications, documents, etc., referenced in this application are incorporated herein by reference in their entirety, except for prosecution history documents that are inconsistent or inconsistent with the content of this application, and documents that may have a limiting effect on the broadest scope of the claims of this application (now or later related to this application). In addition, if the statements, definitions, and / or use of terms in the accompanying documents of this application are inconsistent or inconsistent with the content set forth in this application, the statements, definitions, and / or use of terms in this application shall control.

[0095] Finally, it should be understood that the embodiments herein are merely illustrative of the principles of the embodiments of the present application. Other variations may be within the scope of the present application. Thus, by way of example, and not of limitation, alternative configurations of the embodiments of the present application may be considered consistent with the teachings of the present application. Accordingly, the embodiments of the present application are not limited to the embodiments expressly introduced and described herein. [Explanation of symbols]

[0096] 100 Audio output device 10 Speakers 11. Housing 12 Energy conversion devices 13 Vibration Panel 14 Vibration-damping sheet 15 Diaphragm 16 Air Conduction Speaker 20 Fixing Assembly 111 Front Cavity 112 Rear cavity 113 Sound emission hole 121 Bracket 122 Vibration transmission sheet 123 Magnetic Circuit System 124 Coil 125 First vibration transmission sheet 126 Second vibration transmission sheet 131 Connecting rod 1231 Magnet Assembly 1232 Magnetic flux conducting cover 1233 Magnet 1234 First magnetic flux conducting plate 1235 Second Flux Conducting Plate 1241 First Coil 1242 Second Coil 1251 Support Rod 1252 Central area 1253 Edge area 1232a Hollow structure 1233a First hole 1234a Second hole 1252a Through hole

Claims

1. a magnetic circuit system including a magnet assembly and a magnetic flux conductive cover disposed so as to at least partially surround the magnet assembly; a vibration transmission sheet including a first vibration transmission sheet and a second vibration transmission sheet, which are respectively distributed on both sides of the magnet assembly along a vibration direction of the magnet assembly and elastically support the magnet assembly within a magnetic flux conductive cover, An energy conversion device having a resonant peak frequency of less than 300 Hz.

2. The energy conversion device according to claim 1 , characterized in that the vibration transmission sheet has a total axial elastic modulus of less than 18,000 N / m.

3. 3. The energy conversion device according to claim 1, wherein the first vibration transmission sheet or the second vibration transmission sheet has an axial elastic modulus of less than 9000 N / m.

4. The energy conversion device of any one of claims 1 to 3, characterized in that the first vibration transmission sheet or the second vibration transmission sheet includes an edge region, a central region, and a plurality of support rods connecting the edge region and the central region, and the central region is connected to the magnet assembly.

5. The energy conversion device of claim 4, characterized in that for one of the multiple support rods, the ratio of the distance along the longitudinal direction of the first vibration transmission sheet or the second vibration transmission sheet between the start point and the end point of the support rod to the length of the support rod is in the range of 0 to 1.

2.

6. One of the plurality of support rods is The length of the support rod is within the range of 7 mm to 25 mm; The thickness of the support rod is in the range of 0.1 mm to 0.2 mm; The width of the support rod is in the range of 0.25 mm to 0.5 mm; or The energy conversion device according to claim 4 or 5, characterized in that it satisfies one or more conditions that the ratio of the thickness of the vibration transmission sheet on which the support rod is located to the width of the support rod is within the range of 0.16 to 0.

75.

7. The energy conversion device according to any one of claims 4 to 6, characterized in that the magnet assembly includes a magnet, and a first magnetic flux conducting plate and a second magnetic flux conducting plate fixed on either side of the magnet in the vibration direction of the magnet assembly, and a central region of the first vibration transmitting sheet is connected to the first magnetic flux conducting plate, and a central region of the second vibration transmitting sheet is connected to the second magnetic flux conducting plate.

8. 8. The energy conversion device according to claim 7, characterized in that a first hole is provided in the magnet and a second hole is provided in the magnetic flux conducting plate, the second hole being provided corresponding to the first hole.

9. 9. An energy conversion device according to claim 7 or 8, characterized in that the ratio between the thickness of the magnetic flux conducting plates and the thickness of the magnets is in the range of 0.05 to 0.

35.

10. An energy conversion device as described in any one of claims 7 to 9, characterized in that an edge region of the first vibration transmission sheet is connected to one end of the magnetic flux conducting cover along the vibration direction of the magnet assembly, and an edge region of the second vibration transmission sheet is connected to the other end of the magnetic flux conducting cover along the vibration direction of the magnet assembly, thereby the first vibration transmission sheet and the second vibration transmission sheet elastically support the magnet assembly.

11. 11. The energy conversion device according to claim 10, wherein at least one of the magnet, the magnetic flux conducting plate and the magnetic flux conducting cover includes a plurality of magnetic portions having different magnetization directions.

12. The energy conversion device according to any one of claims 1 to 11, further comprising a coil installed in the magnetic circuit system, the magnetic flux conducting cover being fitted to the outside of the coil, and an inner wall of the magnetic flux conducting cover being in close contact with an outer wall of the coil.

13. 13. The energy conversion device according to claim 12, characterized in that the number of coils along the radial direction of the energy conversion device is even, whereby the input and output wires of the coils are at the same position on the magnetic flux conducting cover.

14. The energy conversion device according to claim 12 or 13, characterized in that the coil includes a first coil and a second coil, the first coil and the second coil are arranged along a vibration direction of the energy conversion device, and a ratio of an axial height to a radial width of the first coil or the second coil is 3.5 or more.

15. 15. An energy conversion device according to claim 14, characterized in that the overall DC impedance of the coil is in the range of 6Ω to 10Ω.

16. The first vibration transmission sheet or the second vibration transmission sheet has an equivalent stiffness of 4.7×10 in any direction in a plane perpendicular to the vibration direction of the magnet assembly. ４ The energy conversion device according to any one of claims 1 to 15, characterized in that the resistance is greater than N / m.

17. 17. The energy conversion device according to claim 12, wherein the mass of the energy conversion device is in the range of 2 g to 5 g.

18. A loudspeaker comprising a housing, an electronic component, and an energy conversion device according to any one of claims 1 to 16, the housing forming a cavity for accommodating the energy conversion device and the electronic component.

19. 20. A loudspeaker as claimed in claim 18, characterized in that the electronic components include vibration sensitive components perpendicular to the vibration direction of the energy conversion device.

20. 20. The loudspeaker of claim 19, wherein the vibration sensitive component includes an air conduction loudspeaker, and the vibration direction of the energy conversion device is perpendicular to the vibration direction of a diaphragm of the air conduction loudspeaker.

21. 19. The speaker of claim 18, characterized in that the electronic components include an air conduction speaker, the diaphragm of the air conduction speaker being connected between the magnet assembly and the housing of the energy conversion device, and the vibration direction of the diaphragm being parallel to the vibration direction of the energy conversion device.

22. 22. An audio output device comprising a fixing assembly and a loudspeaker according to any one of claims 18 to 21, said fixing assembly being connected to said loudspeaker.

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