A micro speaker

Abstract

This invention discloses a miniature loudspeaker, comprising an upper housing, a lower housing covering the upper housing, and a loudspeaker unit fixed between the upper and lower housings. The upper housing is divided into a front acoustic cavity and a rear acoustic cavity by the diaphragm of the loudspeaker unit. A first sound outlet communicating with the front acoustic cavity and a second sound outlet are provided on the upper housing. A bass-reflex channel is provided between the upper and lower housings, with one end communicating with the rear acoustic cavity and the other end communicating with the second sound outlet. Sound waves generated by the forced vibration of the diaphragm in the front acoustic cavity are radiated to the outside through the front acoustic cavity and the first sound outlet. Sound waves generated by the diaphragm in the rear acoustic cavity are radiated to the outside through the rear acoustic cavity, the bass-reflex channel, and the second sound outlet, or radiated to the outside again through the first sound outlet. This invention, through its bass-reflex structure design, effectively improves the loudness of the miniature loudspeaker without affecting other acoustic performance characteristics.

Description

Technical Field

[0001] This invention relates to the field of electroacoustic product technology, and in particular to a miniature loudspeaker. Background Technology

[0002] Currently, most commonly used loudspeaker designs are based on the fundamental principle that a planar vibrating system radiates sound forward while also radiating sound backward. Here, "forward" refers to the direction of the normal to the plane of the vibrating system, and "backward" refers to the opposite direction. Because low-frequency sound waves have significant fluctuations, the backward-radiated sound bypasses the vibrating system and interferes with the forward-radiated sound, causing sound field fluctuations and phase disorder, resulting in inconsistent sound volume. To avoid this phenomenon, a closed-box loudspeaker was designed, which encloses the backward-radiated sound within a small space and uses algorithms to control it so that it does not interfere with the forward-radiated sound, but rather reinforces it.

[0003] To fully utilize rearward-radiated sound, existing bass-reflex loudspeaker designs, based on the closed-box loudspeaker design, create a channel within the sealed rear cavity, allowing rearward-radiated sound to still propagate and interfere with forward-radiated sound. However, because this channel is artificially designed, the degree of interference between forward and rearward-radiated sound can be strictly controlled, causing this interference to develop in a direction beneficial to increasing loudness in the low-frequency range.

[0004] However, applying bass-reflex technology in the field of miniature loudspeakers is quite challenging: First, it requires complex algorithms to control the radiated sound waves; second, the application scenarios are complex, necessitating consideration of the device itself and its compatibility with external system structures; third, its small size makes conventional bass-reflex designs unsuitable for direct application; and fourth, its compact design makes bass-reflexion prone to performance degradation in other areas, creating a ripple effect. Therefore, this technology has not been successfully applied in the field of miniature loudspeakers for some time. Summary of the Invention

[0005] The purpose of this invention is to provide a miniature loudspeaker that effectively improves the loudness of the miniature loudspeaker without affecting other acoustic properties.

[0006] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0007] A miniature loudspeaker includes an upper housing, a lower housing covering the upper housing, and a loudspeaker unit fixed between the upper housing and the lower housing. The loudspeaker unit includes a diaphragm that divides the upper housing into a front acoustic cavity and a rear acoustic cavity. The upper housing has a first sound outlet hole communicating with the front acoustic cavity.

[0008] The upper housing is also provided with a second sound outlet;

[0009] A phase-reversing acoustic channel is provided between the upper housing and the lower housing. One end of the phase-reversing acoustic channel is connected to the rear acoustic cavity, and the other end is connected to the second sound outlet. The distance between the center points of the first sound outlet and the second sound outlet is less than 100mm.

[0010] The sound waves generated by the forced vibration diaphragm in the front acoustic cavity are radiated to the outside through the front acoustic cavity and the first sound outlet. The sound waves generated by the forced vibration diaphragm in the rear acoustic cavity are radiated to the outside through the rear acoustic cavity, the phase-reversing acoustic channel and the second sound outlet, or are radiated to the outside through the first sound outlet.

[0011] Preferably, the first sound outlet and the second sound outlet are spaced apart and disposed on the same side of the upper housing, and a sealing sidewall is provided between the second sound outlet and the first sound outlet to completely isolate the sound waves generated in the front and rear sound cavities.

[0012] Preferably, the second sound outlet is connected to the first sound outlet and disposed on the same side of the housing, and the sound waves generated in the front and rear sound cavities radiate to the outside through the same sound outlet.

[0013] Preferably, the upper housing is provided with a receiving groove, and the diaphragm of the speaker unit is embedded in the receiving groove to separate the sound waves generated on the front and rear sides of the diaphragm. The receiving groove and the front side of the diaphragm of the speaker unit together form the front acoustic cavity; the upper housing, the lower housing, and the rear side of the diaphragm of the speaker unit, excluding the portion of the receiving groove, together form the rear acoustic cavity.

[0014] Preferably, the speaker unit has one or more sound outlet holes at its corners or center, and the side of the speaker unit diaphragm facing away from the front acoustic cavity is connected to the rear acoustic cavity through the sound outlet holes.

[0015] Preferably, the receiving groove has a first outer side wall, the upper housing has a second outer side wall and a top wall connected between the first outer side wall and the second outer side wall, and the first outer side wall, the second outer side wall, the top wall and the lower housing together surround to form the phase-reversing acoustic channel.

[0016] Preferably, a sealing element is provided around the port portion of the first sound outlet near the front acoustic cavity and the port portion of the second sound outlet near the phase-reversing acoustic channel, and the sealing element is fitted and fixed to the outer wall of the port portion.

[0017] Preferably, a dustproof net is provided outside the first and second sound outlets.

[0018] Preferably, the rear acoustic cavity includes multiple sub-rear acoustic cavities of different sizes, and adjacent sub-rear acoustic cavities are provided with channels to communicate with each other.

[0019] Preferably, the diameter of the speaker unit is less than or equal to 40 mm.

[0020] Compared with the prior art, the present invention has the following advantages:

[0021] The miniature loudspeaker disclosed in this invention divides the housing into a front acoustic cavity and a rear acoustic cavity through the diaphragm of the loudspeaker unit. A first sound outlet and a second sound outlet are formed on the housing. The first sound outlet is directly connected to the front acoustic cavity, and the second sound outlet is connected to the rear acoustic cavity through a bass reflex channel set in the housing. The direction of sound waves generated in the front acoustic cavity radiating to the outside is the same as or similar to the direction of sound waves generated in the rear acoustic cavity radiating to the outside. This improves the loudspeaker loudness without affecting the volume of the front and rear acoustic cavities, the design of the loudspeaker unit, or other acoustic performance. At the same time, the size of the second sound outlet can be changed according to actual needs. The heat and pressure generated in the rear acoustic cavity are also directly dissipated through the bass reflex channel and the second sound outlet, which can further improve the heat dissipation and pressure relief effect of the loudspeaker. Furthermore, the number of the second sound outlet and the bass reflex channel can be set according to the size of the rear acoustic cavity to ensure uniform transmission of sound waves generated in the rear acoustic cavity. Attached Figure Description

[0022] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of the invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and are not intended to specifically limit the shapes and proportions of the components. Those skilled in the art, guided by the teachings of this invention, can select various possible shapes and proportions to implement the invention according to specific circumstances. In the drawings:

[0023] Figure 1 This is a schematic diagram of the structure of the miniature loudspeaker in Embodiment 1 of the present invention;

[0024] Figure 2 This is a schematic diagram of the upper shell structure in Embodiment 1 of the present invention;

[0025] Figure 3 This is a cross-sectional view of a section of a miniature loudspeaker in Embodiment 1 of the present invention;

[0026] Figure 4 This is a cross-sectional view of another cut position of the miniature loudspeaker in Embodiment 1 of the present invention;

[0027] Figure 5 This is a top view of the miniature loudspeaker in Embodiment 1 of the present invention;

[0028] Figure 6 yes Figure 5 Sectional view of AA;

[0029] Figure 7 This is a radiation path diagram of the sound waves generated in the front and rear acoustic cavities in Embodiment 1 of the present invention;

[0030] Figure 8 This is a radiation path diagram of the sound waves generated in the front and rear acoustic cavities in Embodiment 2 of the present invention;

[0031] Figure 9 This is a top view of the miniature loudspeaker in Embodiment 3 of the present invention;

[0032] Figure 10 yes Figure 9 Sectional view of BB;

[0033] Figure 11 This is a radiation path diagram of the sound waves generated in the front and rear acoustic cavities in Embodiment 3 of the present invention;

[0034] Figure 12 This is a radiation path diagram of the sound waves generated in the front and rear acoustic cavities in Embodiment 4 of the present invention;

[0035] As shown in the figure:

[0036] 1. Housing; 11. Upper housing; 111. Second outer side wall; 112. Top wall; 12. Lower housing; 13. Receiving groove; 131. First outer side wall; 14. First sound outlet; 15. Second sound outlet; 15a. Sub-second sound outlet; 16. Inverted bass channel; 17. Sealed side wall; 18. First connecting channel; 2. Loudspeaker unit; 21. Housing; 22. Vibration system; 221. Diaphragm; 2211. Dome; 2212. Surround; 222. Voice coil; 23. Magnetic circuit system; 231. Washer; 232. Magnet; 31. Front acoustic cavity; 32. Rear acoustic cavity; 32a. Sub-rear acoustic cavity; 32b. Channel; 4. Seal. Detailed Implementation

[0037] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0038] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only embodiments.

[0039] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0040] The miniature loudspeaker of the present invention has a loudspeaker unit with a diameter ≤40mm. The miniature loudspeaker includes an upper housing, a lower housing covering the upper housing, and a loudspeaker unit fixed between the upper housing and the lower housing. The loudspeaker unit includes a diaphragm that divides the upper housing into a front acoustic cavity and a rear acoustic cavity. A first sound outlet hole communicating with the front acoustic cavity is provided on the upper housing, and a second sound outlet hole is also provided on the upper housing.

[0041] A phase-reversing acoustic channel is provided between the upper and lower housings. One end of the phase-reversing acoustic channel is connected to the rear acoustic cavity, and the other end is connected to the second sound outlet. The center point distance between the first sound outlet and the second sound outlet is less than 100mm. The sound waves generated by the forced vibrating diaphragm in the front acoustic cavity are radiated to the outside through the front acoustic cavity and the first sound outlet. The sound waves generated by the forced vibrating diaphragm in the rear acoustic cavity are radiated to the outside through the rear acoustic cavity, the phase-reversing acoustic channel, and the second sound outlet, or radiated to the outside through the first sound outlet. The direction of the sound waves generated in the front acoustic cavity radiating to the outside is the same as or similar to the direction of the sound waves generated in the rear acoustic cavity radiating to the outside.

[0042] Example 1:

[0043] like Figures 1 to 6 As shown, a miniature loudspeaker corresponding to a preferred embodiment of the present invention includes a housing 1 and a loudspeaker unit 2 fixed within the housing 1. The housing 1 specifically includes an upper housing 11 and a lower housing 12 covering the upper housing 11. The upper housing 11 and the lower housing 12 can be sealed and fixed together by applying adhesive or ultrasonic welding. The diaphragm 221 of the loudspeaker unit 2 divides the upper housing 11 into a front acoustic cavity 31 and a rear acoustic cavity 32. In this embodiment, the front acoustic cavity 31 is disposed near the upper housing 11, and the rear acoustic cavity 32 is disposed near the lower housing 12.

[0044] like Figure 3As shown, in this embodiment, the speaker unit 2 preferably has a rectangular structure, including a housing 21, a vibration system 22, and a magnetic circuit system 23. The vibration system 22 includes a diaphragm 221 disposed on one side of the housing 21 and a voice coil 222 coupled to one side of the diaphragm 221. The voice coil 222 is disposed inside the housing 21. In this invention, the side of the diaphragm 221 away from the voice coil 222 is defined as the front side, and the side of the diaphragm closer to the voice coil 222 is defined as the rear side. The magnetic circuit system 23 is disposed inside the housing 21 and includes a washer 231 and a magnet 232 coupled in sequence. The magnetic circuit system 23 forms a magnetic gap to accommodate the voice coil 222. When the voice coil 222 is connected to an electrical signal, it is subjected to force and vibrates up and down in the magnetic field formed by the magnetic circuit system 23, which further drives the diaphragm 221 to vibrate and generate sound.

[0045] Preferred, such as Figure 2 As shown, the upper housing 11 has a receiving groove 13. The diaphragm 221 includes a rigid dome 2211 at the center of the diaphragm 221 and a flexible folded ring 2212 at the edge of the diaphragm 221. The outer edge of the dome 2211 is pressed by the inner edge of the folded ring 2212. The folded ring 2212 is embedded in the receiving groove 13 to separate the sound waves generated on the front and rear sides of the diaphragm 221. In this embodiment, the front acoustic cavity 31 is formed by the receiving groove 13 and the front side of the diaphragm 221 of the speaker unit 2. The rear acoustic cavity 32 is formed by the upper housing 11 (excluding the portion of the receiving groove 13), the lower housing 12, and the rear side of the diaphragm 221 of the speaker unit 2.

[0046] like Figure 3 As shown, the upper housing 11 has a first sound outlet 14 that communicates with the front acoustic cavity 31. The first sound outlet 14 is a sound guiding structure with a certain length, which can be sealed with external systems or some auxiliary structures such as dustproof nets, so that the sound waves generated by the forced vibration of the diaphragm 221 in the speaker unit 2 in the front acoustic cavity 31 are radiated to the outside through the front acoustic cavity 31 and the first sound outlet 14.

[0047] like Figure 4As shown, in this embodiment, the upper housing 11 is also provided with a second sound outlet 15, which is spaced apart from the first sound outlet 14 and located on the same side of the housing 1. The center point distance between the first and second sound outlets is less than 100mm. The second sound outlet 15 is the end of the bass reflex channel 16 away from the rear acoustic cavity 32. The second sound outlet 15 is also a sound guiding structure with a certain length, which can be sealed with external systems or some auxiliary structures such as dustproof nets. A bass reflex channel 16 is provided between the upper housing 11 and the lower housing 12. One end of the bass reflex channel 16 is connected to the rear acoustic cavity 32, and the other end is connected to the second sound outlet 15. The corner or middle of the speaker unit 2 is provided with one or more sound outlets. The side of the speaker unit 2 diaphragm 221 facing away from the front acoustic cavity 31 is connected to the rear acoustic cavity 32 through the sound outlet. The sound waves generated by the forced vibration of the diaphragm 221 in the loudspeaker unit 2 in the rear acoustic cavity are radiated to the outside through the rear acoustic cavity 32, the bass reflex channel 16 and the second sound outlet 15. The sound waves generated in the front acoustic cavity 31 are radiated to the outside in the same or similar direction as the sound waves generated in the rear acoustic cavity 32. Without affecting the volume of the front acoustic cavity 31 and the rear acoustic cavity 32, as well as the design of the loudspeaker unit 2, the low frequency loudness is greatly improved.

[0048] Specifically, the receiving slot 13 has a first outer side wall 131, the upper housing 11 has a second outer side wall 111 and a top wall 112 connecting the first outer side wall 131 and the second outer side wall 111. The first outer side wall 131 and the second outer side wall 111 together form a channel, and the reverse sound channel 16 is formed by the first outer side wall 131, the second outer side wall 111, the top wall 112 and the lower housing 12 together.

[0049] Preferably, a sealing sidewall 17 is provided between the second sound outlet 15 and the first sound outlet 14 to completely isolate the sound waves generated in the front and rear acoustic cavities. The second sound outlet 15 and the first sound outlet 14 are not necessarily located on the same plane. As long as the direction of the sound waves generated in the front acoustic cavity radiating to the outside is the same as or similar to the direction of the sound waves generated in the rear acoustic cavity radiating to the outside, the low-frequency loudness can be greatly improved without affecting the volume of the front and rear acoustic cavities 31 and the design of the speaker unit 2. In this embodiment, a sealing member 4 is provided around the end of the first sound outlet 14 near the front acoustic cavity 31 and the port portion of the second sound outlet 15 near the bass reflex channel 16. The sealing member 4 is fitted and fixed to the outer wall of the port portion to ensure the isolation of the sound waves generated in the front and rear acoustic cavities.

[0050] like Figures 5 to 7As shown, in this embodiment, the first sound outlet 14 is located on the side, but it is not limited to this position; it can also be located on the side directly opposite the speaker unit 2. The speaker unit 2 is fixedly attached to the receiving groove 13. The front side of the diaphragm 221 of the speaker unit 2 and the receiving groove 13 together form the front acoustic cavity 31 of the speaker. The front acoustic cavity 31 is connected to the first sound outlet 14. The sound waves generated by the forced vibration of the diaphragm 221 in the speaker unit 2 in the front acoustic cavity are radiated to the outside through the front acoustic cavity 31 and the first sound outlet 14 (e.g., Figure 7 (As shown by the solid arrow in the image). The second sound outlet 15 is also located on the side and is on the same plane as the first sound outlet 14, but it is not limited to this position. Its position can be changed according to the position of the first sound outlet 14, and its length can also be changed according to actual needs. The first sound outlet 14 and the second sound outlet 15 are completely sealed and isolated from each other. The rear side of the diaphragm of the speaker unit 2, the upper housing 11 excluding the portion of the receiving groove 13, and the lower housing 12 together form the rear acoustic cavity 32 of the speaker. The rear acoustic cavity 32 is connected to the second sound outlet 15 through the bass reflex channel 16. The bass reflex channel 16 is formed by the first outer side wall 131 of the receiving groove 13, the second outer side wall 111 of the upper housing 11, the top wall 112 of the upper housing 11, and the lower housing 12. The sound waves generated in the rear acoustic cavity 32 by the forced vibration of the diaphragm 221 in the speaker unit 2 are radiated to the outside through the rear acoustic cavity 32, the bass reflex channel 16, and the second sound outlet 15 (e.g., Figure 7 (As shown by the dashed arrow in the image). The direction in which the sound waves generated in the front acoustic cavity radiate to the outside is the same as the direction in which the sound waves generated in the rear acoustic cavity radiate to the outside. This design greatly improves the low-frequency loudness without affecting the volume of the front acoustic cavity 31 and the rear acoustic cavity 32, or the design of the speaker unit 2.

[0051] Example 2:

[0052] In this embodiment, as Figure 8 As shown, the second sound outlet 15 is connected to the first sound outlet 14 and is located on the same side of the housing 1. The sound waves generated in the front and rear acoustic cavities radiate to the outside through the same sound outlet, ensuring that the direction of the sound waves radiated from the front cavity to the outside is the same as that of the sound waves radiated from the rear cavity. Without affecting the volume of the front acoustic cavity 31 and the rear acoustic cavity 32, as well as the design of the speaker unit 2, the low-frequency loudness is greatly improved. The rest of the structure is the same as in Embodiment 1.

[0053] In this embodiment, the preferred connection between the second sound outlet 15 and the first sound outlet 14 is that a first connecting channel 18 is opened between the second sound outlet 15 and the first sound outlet 14. The sound waves generated in the acoustic cavity, after being transmitted to the second sound outlet 15, do not directly radiate to the outside, but instead are transmitted through the first connecting channel 18 to the first sound outlet 14, and then radiated to the outside through the first sound outlet 14 (e.g., ...). Figure 8(As shown by the dashed arrow in the image), this allows the sound waves generated in the front and rear acoustic cavities to radiate to the outside through the same sound outlet.

[0054] Example 3:

[0055] In this embodiment, as Figure 9 and Figure 10 As shown, when the rear acoustic cavity 32 is designed with an irregular shape, that is, when the rear acoustic cavity 32 includes multiple sub-rear acoustic cavities 32a of different sizes, and adjacent sub-rear acoustic cavities 32a are connected by channels 32b, and when the cross-section of the channel 32b is smaller than the cross-section of any sub-rear acoustic cavity 32a connected to its two sides, setting up a phase-reversing acoustic channel may not be able to uniformly transmit the sound waves generated in the rear acoustic cavity 32. Therefore, in this embodiment, the second sound outlet 15 includes multiple sub-second sound outlets 15a corresponding to the sub-rear acoustic cavities 32a, and each sub-rear acoustic cavity 32a and its corresponding sub-second sound outlet 15a are connected by a phase-reversing acoustic channel 16. The remaining structure is the same as in Embodiment 1.

[0056] like Figure 11 As shown, in this embodiment, the first sound outlet 14 is located on the side, but it is not limited to this position; it can also be located on the side directly opposite the speaker unit 2. The speaker unit 2 is fixedly attached to the receiving groove 13. The front side of the diaphragm 221 of the speaker unit 2 and the receiving groove 13 together form the front acoustic cavity 31 of the speaker. The front acoustic cavity 31 is connected to the first sound outlet 14. The sound waves generated by the forced vibration of the diaphragm 221 in the speaker unit 2 in the front acoustic cavity are radiated to the outside through the front acoustic cavity 31 and the first sound outlet 14 (e.g., Figure 11 (As shown by the solid arrow in the image). Each sub-second sound outlet 15a is also located on the same side as the first sound outlet 14. Figure 11 The diagram shows a structural schematic when the rear acoustic cavity 32 is composed of two sub-rear acoustic cavities 32a of different sizes, but it is not limited to this position. Its location can be changed according to the position of the first sound outlet 14, and its length can also be changed according to actual needs. The first sound outlet 14 is completely sealed and isolated from each sub-secondary sound outlet 15a. The rear side of the diaphragm of the speaker unit 2, the upper housing 11 excluding the receiving groove 13, and the lower housing 12 together form the rear acoustic cavity 32 of the speaker. The rear acoustic cavity 32 is composed of two sub-rear acoustic cavities 32a of different sizes that are interconnected. Each sub-rear acoustic cavity 32a is connected to its corresponding sub-secondary sound outlet 15a by a phase-reversing acoustic channel 16. The sound waves generated in the sub-rear acoustic cavities 32a by the forced vibration of the diaphragm 221 in the speaker unit 2 are radiated to the outside through the corresponding sub-rear acoustic cavities 32a, the phase-reversing acoustic channel 16, and the sub-secondary sound outlet 15a (e.g., Figure 11(As shown by the dashed arrow in the image). The direction in which the sound waves generated in the front acoustic cavity radiate to the outside is the same as the direction in which the sound waves generated in the rear acoustic cavity radiate to the outside. This design greatly improves the low-frequency loudness without affecting the volume of the front acoustic cavity 31 and the rear acoustic cavity 32, as well as the design of the speaker unit 2. At the same time, independent bass-reflex channels 16 are set for the different sizes of the sub-rear acoustic cavities 32a to ensure that the sound waves generated in each sub-rear acoustic cavity 32a are transmitted evenly.

[0057] Example 4:

[0058] In this embodiment, as Figure 12 As shown, each sub-second sound outlet 15a is connected to the first sound outlet 14 and disposed on the same side of the housing 1. The sound waves generated in the front acoustic cavity and each sub-rear acoustic cavity radiate to the outside through the same sound outlet, ensuring that the direction of the sound waves radiated to the outside from the front cavity is the same as that from the rear cavity. Without affecting the volume of the front acoustic cavity 31 and the rear acoustic cavity 32, as well as the design of the speaker unit 2, the low-frequency loudness is greatly improved, while also ensuring that the sound waves generated in each sub-rear acoustic cavity 32a are transmitted evenly. The rest of the structure is the same as in Embodiment 3.

[0059] In this embodiment, the preferred connection between the sub-second sound outlet 15a and the first sound outlet 14 is that a first connecting channel 18 is opened between each sub-second sound outlet 15a and the first sound outlet 14. The sound waves generated in each sub-rear acoustic cavity, after being transmitted to the sub-second sound outlet 15a, do not directly radiate to the outside, but are transmitted into the first sound outlet 14 through the first connecting channel 18, and then radiated to the outside through the first sound outlet 14 (e.g., ...). Figure 12 (As shown by the dashed arrow in the image), this allows the sound waves generated in the front and rear acoustic cavities to radiate to the outside through the same sound outlet.

[0060] The miniature loudspeaker disclosed in this invention divides the housing into a front acoustic cavity and a rear acoustic cavity through the diaphragm of the loudspeaker unit. A first sound outlet and a second sound outlet are formed on the upper shell of the housing. The first sound outlet directly communicates with the front acoustic cavity, and the second sound outlet communicates with the rear acoustic cavity through a bass reflex channel located within the housing. The direction in which the sound waves generated in the front acoustic cavity radiate to the outside is the same as or similar to the direction in which the sound waves generated in the rear acoustic cavity radiate to the outside. This improves the loudspeaker's loudness without affecting the volume of the front and rear acoustic cavities, the design of the loudspeaker unit, or other acoustic performance characteristics. Simultaneously, the size of the second sound outlet can be changed according to actual needs, and the heat and pressure generated in the rear acoustic cavity are also directly dissipated through the bass reflex channel and the second sound outlet, further improving the loudspeaker's heat dissipation and pressure relief effect. Furthermore, the number of the second sound outlet and the bass reflex channel can be correspondingly set according to the size of the rear acoustic cavity to ensure uniform transmission of the sound waves generated in the rear acoustic cavity. In summary, the miniature loudspeaker disclosed in this invention effectively improves the loudspeaker's loudness without affecting other acoustic performance characteristics.

[0061] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of this teaching should not be determined by reference to the above description, but rather by reference to the foregoing claims and the full scope of their equivalents. For purposes of completeness, all articles and references, including patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended as a waiver of that subject matter, nor should it be construed as an indication that the applicant has not considered that subject matter as part of the disclosed inventive subject matter.

Claims

1. A miniature loudspeaker, comprising an upper housing, a lower housing covering the upper housing, and a loudspeaker unit fixed between the upper housing and the lower housing, the loudspeaker unit comprising a diaphragm dividing the upper housing into a front acoustic cavity and a rear acoustic cavity, the upper housing having a first sound outlet communicating with the front acoustic cavity, characterized in that, The upper housing is also provided with a second sound outlet; A phase-reversing acoustic channel is provided between the upper housing and the lower housing. One end of the phase-reversing acoustic channel is connected to the rear acoustic cavity, and the other end is connected to the second sound outlet. The distance between the center points of the first sound outlet and the second sound outlet is less than 100mm. A first connecting channel is provided between the second sound outlet and the first sound outlet. The sound waves generated by the forced vibrating diaphragm in the front sound cavity are radiated to the outside through the front sound cavity and the first sound outlet. The sound waves generated by the forced vibrating diaphragm in the rear sound cavity are radiated to the outside through the rear sound cavity, the phase inversion channel, the second sound outlet, and the first connecting channel, and then through the first sound outlet, without passing through the front sound cavity. The diameter of the speaker unit is less than or equal to 40 mm; The first sound outlet and the second sound outlet are spaced apart and disposed on the same side of the upper housing, and a sealing sidewall is provided between the second sound outlet and the first sound outlet to completely isolate the sound waves generated in the front and rear sound cavities.

2. The miniature loudspeaker according to claim 1, characterized in that, The second sound outlet is connected to the first sound outlet and is located on the same side of the housing. The sound waves generated in the front and rear sound cavities radiate to the outside through the same sound outlet.

3. The miniature loudspeaker according to claim 1, characterized in that, The upper housing is provided with a receiving groove, and the diaphragm of the speaker unit is embedded in the receiving groove to separate the sound waves generated on the front and rear sides of the diaphragm. The receiving groove and the front side of the diaphragm of the speaker unit together form the front acoustic cavity. The upper housing, the lower housing, and the rear side of the diaphragm of the speaker unit, excluding the portion of the receiving groove, together form the rear acoustic cavity.

4. The miniature loudspeaker according to claim 3, characterized in that, The speaker unit has one or more sound outlet holes at its corners or center, and the side of the speaker unit diaphragm facing away from the front acoustic cavity is connected to the rear acoustic cavity through the sound outlet holes.

5. The miniature loudspeaker according to claim 3, characterized in that, The receiving slot has a first outer side wall, the upper housing has a second outer side wall and a top wall connected between the first outer side wall and the second outer side wall, and the first outer side wall, the second outer side wall, the top wall and the lower housing together surround to form the phase-reversing acoustic channel.

6. The miniature loudspeaker according to claim 1, characterized in that, The first sound outlet near the front acoustic cavity and the second sound outlet near the phase-reversing acoustic channel are both surrounded by a sealing element, which is fixedly attached to the outer wall of the port.

7. The miniature loudspeaker according to claim 1, characterized in that, Dustproof nets are provided outside the first and second sound outlets.

8. The miniature loudspeaker according to claim 1, characterized in that, The rear acoustic cavity includes multiple sub-rear acoustic cavities of varying sizes, and adjacent sub-rear acoustic cavities are connected by channels.

Images