A loudspeaker module and an electronic product

Abstract

The present invention provides a speaker module and an electronic product. The speaker module includes: a housing and a speaker unit, the speaker unit is disposed within the housing and divides the housing into a front sound emission area and a rear sound cavity; an acoustic duct having an inlet and an outlet, the inlet communicating with the rear sound cavity; the ratio of the length L to the cross-sectional area S of the acoustic duct is 1.6 / mm < L / S < 9 / mm; a closed cavity, the outlet of the acoustic duct communicating with the closed cavity, the sound transmitted from the outlet being enclosed within the closed cavity and isolated from the sound transmitted from the front sound emission area. By providing an acoustic duct on the speaker module and setting the ratio of the length to the cross-sectional area of the acoustic duct to 1.6 / mm < L / S < 9 / mm, the resonance frequency of the speaker module can be reduced and the low-frequency sensitivity below 500 Hz of the speaker module can be improved.

Description

Technical Field

[0001] The present invention relates to the field of acoustic technologies, and more particularly, to a speaker module and an electronic product. Background Art

[0002] As an electro-acoustic conversion device, a speaker module is commonly used as a sound-emitting component in electronic products. Due to the increasingly miniaturized volume of electronic products, the installation space for the speaker module has been greatly reduced, and the size of the speaker module is increasingly restricted. When the size of the speaker module decreases, the volume of the rear cavity of the corresponding module decreases, which has an adverse effect on the low-frequency performance of the speaker module. Therefore, the low-frequency sound effect of the current speaker module urgently needs to be improved, and the bass effect of the speaker module is mainly controlled by the volume of the rear sound cavity. When the volume of the rear sound cavity is large, the bass effect is better.

[0003] Therefore, it is necessary to propose a speaker module that can greatly improve the low-frequency sensitivity of sound without increasing the rear sound cavity. Summary of the Invention

[0004] An object of the present invention is to provide a speaker module to solve the problem of poor low-frequency sound effect of the existing speaker module

[0005] An object of the present invention is to provide an electronic product in which the above-mentioned speaker module is installed.

[0006] A speaker module includes:

[0007] A housing and a speaker unit, the speaker unit is disposed within the housing, and the speaker unit divides the housing into a front sound-emitting area and a rear sound cavity;

[0008] An acoustic duct having an inlet and an outlet, the inlet being communicated with the rear sound cavity;

[0009] The ratio of the length L to the cross-sectional area S of the acoustic duct is 1.6 / mm < L / S < 9 / mm;

[0010] A closed cavity, the outlet of the acoustic duct is communicated with the closed cavity, and the sound transmitted from the outlet is enclosed in the closed cavity and isolated from the sound transmitted from the front sound-emitting area..

[0011] Optionally, the length L of the acoustic duct is 4mm < L < 15mm.

[0012] Optionally, the cross-sectional shape of the acoustic duct is circular or polygonal.

[0013] Optionally, the cross-sectional shape of the acoustic duct is circular, and the diameter D of the acoustic duct is 1mm < D < 3mm.

[0014] Optionally, the acoustic duct is disposed in the rear sound cavity, is arranged along the inner edge of the housing, and fits with the inner edge of the housing.

[0015] Optionally, a part of the structure of the housing for forming the rear sound cavity forms the acoustic duct.

[0016] Optionally, the acoustic duct and the housing are integrally formed by injection molding.

[0017] Optionally, the wall thickness of the acoustic duct is 0.3 - 0.7 mm.

[0018] Optionally, the material of the acoustic duct is a glass fiber reinforced composite material.

[0019] An electronic product includes the above - mentioned speaker module;

[0020] The speaker module is installed in the housing of the electronic product, and the front sound - emitting area faces the sound - emitting hole of the housing;

[0021] The housing forms the closed cavity, and the sound - emitting port of the acoustic duct communicates with the closed cavity.

[0022] The beneficial effect of the technical solution of the present invention lies in that: an acoustic duct is provided on the speaker module, and the ratio of the length to the cross - sectional area of the acoustic duct is set to 1.6 / mm < L / S < 9 / mm, which can reduce the resonance frequency of the speaker module and improve the low - frequency sensitivity of the speaker module below 500 Hz.

[0023] Other features and advantages of the present invention will become clear through the following detailed description of the exemplary embodiments of the present invention with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings incorporated in and constituting a part of this specification illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0025] Figure 1 is an exploded view of a speaker module according to an embodiment of the present invention;

[0026] Figure 2 is a schematic diagram of the internal structure of a speaker module according to an embodiment of the present invention;

[0027] Figure 3 is a schematic diagram of the structure of a speaker module according to an embodiment of the present invention;

[0028] Figure 4 is a cross - sectional view of a speaker module according to an embodiment of the present invention;

[0029] Figure 5 A cross-sectional view of a speaker module according to an embodiment of the present invention;

[0030] Figure 6 An installation schematic diagram of the speaker module in an electronic product according to an embodiment of the present invention;

[0031] Figure 7 A graph showing the relationship between acoustic impedance and frequency when the L / S of the acoustic duct according to an embodiment of the present invention is set within the range of 1.6 - 9 / mm;

[0032] Figure 8 A graph showing the relationship between sound pressure level and frequency of two speaker module structures according to an embodiment of the present invention;

[0033] The markings in the figure are as follows: 10 speaker unit; 20 housing; 201 upper housing; 202 lower housing; 30 acoustic duct; 301 sound inlet; 302 sound outlet; 100 housing of the electronic product. Detailed implementation manners

[0034] Now, various exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that: Unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions, and numerical values set forth in these embodiments do not limit the scope of the present invention.

[0035] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way serves as a limitation to the present invention and its application or use.

[0036] Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the techniques, methods, and devices should be regarded as part of the specification.

[0037] In all the examples shown and discussed herein, any specific value should be construed as merely exemplary and not as a limitation. Therefore, other examples of the exemplary embodiments may have different values.

[0038] It should be noted that: Similar reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0039] The present invention provides a speaker module, comprising: a housing and a speaker unit, the speaker unit being disposed within the housing, the speaker unit dividing the housing into a front sound output region and a rear sound cavity; an acoustic duct having an inlet and an outlet, the inlet being communicated with the rear sound cavity; the ratio of the length L to the cross-sectional area S of the acoustic duct being 1.6 / mm < L / S < 9 / mm; a closed cavity, the outlet of the acoustic duct being communicated with the closed cavity, the sound transmitted from the outlet being enclosed within the closed cavity and isolated from the sound transmitted from the front sound output region.

[0040] Specifically, with reference to Figures 1 to 5 , the speaker module of the present invention includes a housing 20. Optionally, the housing includes an upper housing 201 and a lower housing 202, the upper housing and the lower housing being snap-fitted to form the housing of the speaker module. Specifically, the upper housing and the lower housing may be hermetically connected by ultrasonic welding or bonding. Optionally, positioning structures that cooperate with each other are respectively provided on the upper housing and the lower housing. After the upper housing 201 and the lower housing 202 are snap-fitted, the positioning structures on the upper housing and the lower housing are connected to pre-position the hermetic connection between the upper housing and the lower housing. Optionally, the mutually cooperating positioning structures are a positioning rod and a positioning sleeve, and the positioning rod is inserted into the positioning sleeve to achieve the positioning function. Optionally, a pair of positioning structures may be provided to prevent the upper housing from rotating relative to the lower housing. Optionally, an accommodation cavity is formed within the housing after the upper housing and the lower housing are snap-fitted. The speaker module further includes a speaker unit 10. The speaker unit, as a sound-emitting device within the speaker module, is disposed within the housing 20. Optionally, the speaker unit is installed in the accommodation cavity formed by the upper housing 201 and the lower housing 202. As an embodiment, an installation groove may be formed on the inner wall of the housing, and the speaker unit is installed in the installation groove. The speaker unit divides the accommodation cavity into a front sound output region and a rear sound cavity, wherein the front sound output region is used to communicate with the outside of the speaker module and transmit the sound signal outside the speaker module. The rear sound cavity is used to balance the air pressure within the speaker module. The speaker module further includes an acoustic duct 30. The acoustic duct has an inlet 301 and an outlet 302. The inlet is communicated with the rear sound cavity of the speaker module, and the gas in the rear sound cavity can enter the acoustic duct through the inlet 301. The speaker module further includes a closed cavity, the outlet of the acoustic duct being communicated with the closed cavity, the sound transmitted from the outlet being enclosed within the closed cavity and isolated from the sound transmitted from the front sound output region of the speaker module.

[0041] The acoustic duct 30 provided in the present invention is used to reduce the resonance frequency of the speaker module and improve the low-frequency sensitivity of the speaker module. Optionally, the ratio of the length L to the cross-sectional area S of the acoustic duct 30 is 1.6 / mm < L / S < 9 / mm. Setting the L / S of the acoustic duct within the range of 1.6 - 9 / mm can shift the resonance frequency of the speaker diaphragm group to the low-frequency range, for example, less than 500 Hz. This can increase the acoustic impedance in the low-frequency range, thereby improving the low-frequency sensitivity and further optimizing the low-frequency acoustic performance of the speaker module.

[0042] The compliance of a conventional speaker module is formed by the parallel connection of the compliance of the speaker unit and the rear sound cavity, and the acoustic mass is provided by the acoustic mass of the speaker unit. Its f s The formula is as follows:

[0043]

[0044] Where f s : The resonance frequency of the speaker module; Cas: The equivalent acoustic compliance of the speaker unit; Cab: The equivalent acoustic compliance of the air in the rear sound cavity; Mas: The equivalent acoustic mass of the vibration system of the speaker unit.

[0045] In the embodiment of the present invention, the compliance of the speaker module is still formed by the parallel connection of the compliance of the speaker unit and the rear sound cavity, and the acoustic mass is provided by the acoustic mass of the speaker unit and the acoustic duct together. At low frequencies, the acoustic mass of the speaker unit and the acoustic mass of the acoustic duct are equivalent to being in series. Its fs formula is as follows:

[0046]

[0047] Where f s : The resonance frequency of the speaker module; Cas: The equivalent acoustic compliance of the speaker unit; Cab: The equivalent acoustic compliance of the air in the rear sound cavity; Mas: The equivalent acoustic mass of the vibration system of the speaker unit; Mac: The equivalent acoustic mass of the acoustic duct. Since the overall acoustic mass of the speaker module increases, the resonance frequency is reduced.

[0048] According to an embodiment of the present invention, Figure 7 shows the relationship diagram between the acoustic impedance and frequency when the L / S of the acoustic duct 30 is set within the range of 1.6 - 9 / mm, and the acoustic impedance-frequency relationship diagram of a conventional speaker module without an acoustic duct. It can be seen from the table that when the acoustic duct 30 is set and the L / S of the acoustic duct is set within the range of 1.6 - 9 / mm, the resonance peak of the speaker module shifts to the low frequency. At the same time, on the left side of the first intersection point of the two curves, the acoustic impedance of the acoustic duct module structure is significantly higher than that of the conventional module structure. The acoustic impedance corresponds to the sound pressure level of the speaker module. The larger the value of the acoustic impedance, the higher the sound pressure level. Combining Figure 8 , Figure 8It is a graph showing the relationship between the sound pressure level and frequency of two speaker module structures. From Figure 8 it can be seen that, compared with the conventional module structure, the acoustic pipe module structure with the L / S of the acoustic pipe set within the range of 1.6 - 9 / mm has a higher sound pressure level in the frequency range below 500 Hz. The sound pressure level directly reflects the sensitivity of the speaker module, and the higher the sound pressure level, the higher the sensitivity of the speaker module. Thus, it can be known that by setting the L / S of the acoustic pipe 30 within the range of 1.6 - 9 / mm in the present invention, the speaker module has a higher low-frequency sensitivity, and the low-frequency acoustic performance of the module is greatly improved.

[0049] In the present invention, by providing an acoustic pipe on the speaker module and setting the ratio of the length L to the cross-sectional area S of the acoustic pipe as 1.6 / mm < L / S < 9 / mm, the resonance frequency of the speaker module can be significantly reduced, the low-frequency sensitivity below 500 Hz of the speaker module can be improved, and the low-frequency acoustic performance of the speaker module can be optimized.

[0050] Optionally, the length L of the acoustic pipe is 4 mm < L < 15 mm.

[0051] As an embodiment of the present invention, the length L of the acoustic pipe 30 can be set within the range of 4 mm - 15 mm. Setting the length of the acoustic pipe within the above range is not only beneficial to the gas to enter and exit the acoustic pipe, but also when the acoustic pipe with the length within this range is provided on the speaker module, the module has good low-frequency performance.

[0052] Optionally, the cross-sectional shape of the acoustic pipe 30 is circular or polygonal. As an embodiment of the present invention, the cross-sectional shape of the acoustic pipe can be designed as circular. The acoustic pipe with this structure is easy to process, and at the same time, the arc surface can reduce the resistance of gas flow. The cross-sectional shape of the acoustic pipe can also be designed as polygonal. The present invention does not limit the cross-sectional shape of the acoustic pipe, and those skilled in the art can also design the cross-sectional shape into other easily conceivable shapes.

[0053] Optionally, the cross-sectional shape of the acoustic pipe is circular, and the diameter D of the acoustic pipe is 1 mm < D < 3 mm.

[0054] The cross-sectional shape of the acoustic pipe 30 of the present invention can be designed as circular. When the cross-sectional shape is circular, the diameter D of the acoustic pipe can be controlled within the range of 1 mm - 3 mm. The acoustic pipe with the diameter within this range is provided on the speaker module, which has a good improvement effect on the low-frequency sensitivity of the speaker module.

[0055] Optionally, the acoustic pipe is provided in the rear sound cavity, the acoustic pipe is arranged along the inner edge of the housing, and the acoustic pipe is attached to the inner edge of the housing.

[0056] As an embodiment of the present invention, as Figure 4 or Figure 5 shown in the cross-sectional view of the speaker module, the acoustic duct 30 can be installed in the rear sound cavity of the speaker module along the inner edge of the housing 20. Arranging the acoustic duct along the inner edge of the housing can reduce the resistance of gas flow in the rear sound cavity, which is beneficial to shortening the time for the air pressure in the rear sound cavity to reach equilibrium, thereby being beneficial to improving the response sensitivity of the speaker module. Optionally, the acoustic duct can be arranged in close fit with the inner edge of the housing, that is, there is no gap between the acoustic duct and the inner edge of the housing. This way can also reduce the resistance of gas flow in the rear sound cavity and is beneficial to the gas to enter and exit the rear sound cavity of the speaker module through the acoustic duct.

[0057] Optionally, a part of the structure of the housing for forming the rear sound cavity forms the acoustic duct.

[0058] As an embodiment of the present invention, referring to Figure 1 or Figure 3 , a part of the structure of the housing for forming the rear sound cavity forms the acoustic duct 30, that is, the shell wall of the housing forms the pipe wall of the acoustic duct. Using the shell wall of the housing to form the pipe wall of the acoustic duct increases the volume of the rear sound cavity in the speaker module except for the acoustic duct and reduces the weight of the housing. Optionally, the acoustic duct 30 can be integrally formed with the housing 20 of the speaker module. Optionally, referring to Figure 1 , the acoustic duct can be integrally formed with the lower housing 202. In the present invention, the integral formation of the acoustic duct and the housing can not only omit the installation process of the acoustic duct and reduce the manufacturing cost of the speaker module, but also the integrally formed acoustic duct and housing have higher connection strength. Optionally, when the acoustic duct is integrally formed with the housing, the sound outlet 302 of the acoustic duct 30 can be formed on the shell wall of the housing.

[0059] Optionally, the acoustic duct and the housing are integrally formed by an injection molding method.

[0060] As an embodiment of the present invention, the integral formation method of the acoustic duct 30 and the housing 20 of the speaker module can be injection molding. The acoustic duct and the housing formed by injection molding have high structural strength. At the same time, the injection molding process is mature and the process is simple, which is beneficial to reducing the manufacturing cost of the acoustic duct and the housing. Of course, the integral formation method of the acoustic duct and the housing in the present invention is not limited to injection molding, and other molding methods can also be selected, such as compression molding. The present invention does not limit this.

[0061] Optionally, the wall thickness of the acoustic duct 30 is 0.3 - 0.7 mm. By setting the wall thickness of the acoustic duct within the range of 0.3 - 0.7 mm, the overall mass of the acoustic duct is relatively small, and the impact on the weight of the speaker module is relatively small. At the same time, the wall thickness of the acoustic duct is easy to control, facilitating the manufacture of the acoustic duct. In addition, the acoustic duct has a relatively large inner cavity volume, which is conducive to the gas passing through the acoustic duct in and out of the acoustic cavity.

[0062] Optionally, the material of the acoustic duct 30 is a glass fiber reinforced composite material. As an embodiment of the present invention, the acoustic duct can adopt a glass fiber reinforced composite material. The acoustic duct made of the glass fiber reinforced composite material has characteristics such as high specific strength and light weight. At the same time, the glass fiber reinforced composite material has good processability, facilitating the molding of the acoustic duct and helping to reduce its manufacturing cost.

[0063] The present invention also provides an electronic product. Referring to Figure 6 , the electronic product includes the above-mentioned speaker module, using the speaker module as the sound generating device. Optionally, the speaker module is installed inside the housing 100 of the electronic product, and the front sound output area of the speaker module is opposite to the sound outlet hole provided on the housing of the electronic product. In this way, the sound signal generated by the speaker module can be transmitted to the outside of the electronic product through the sound outlet hole and then received by the user. Optionally, the acoustic duct 30 of the present invention is provided on the speaker module, the sound inlet 301 of the acoustic duct faces the rear acoustic cavity of the speaker module and is communicated with the rear acoustic cavity. The gas in the rear acoustic cavity can enter the acoustic duct through the sound inlet, and the sound outlet 302 of the acoustic duct faces the cavity formed by the outer shell 100 of the electronic product. The cavity is the closed cavity formed by the housing of the electronic product. The gas passes through the acoustic duct in and out of the rear acoustic cavity of the speaker module. The electronic product using the above-mentioned speaker module with an acoustic duct has better low-frequency sensitivity and low-frequency acoustic performance, and can bring an excellent acoustic experience to the user.

[0064] Although some specific embodiments of the present invention have been described in detail by way of examples, those skilled in the art should understand that the above examples are only for illustration purposes and not for limiting the scope of the present invention. Those skilled in the art should understand that the above embodiments can be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A speaker module, characterized in that, Comprising: A housing and a speaker unit, the speaker unit being disposed within the housing, the speaker unit dividing the housing into a front sound-emitting area and a rear sound cavity; An acoustic duct having an inlet and an outlet, the inlet communicating with the rear sound cavity; The cross-sectional shape of the acoustic duct is circular, the length L of the acoustic duct satisfies 4 mm < L < 15 mm, the diameter D of the acoustic duct satisfies 1 mm < D < 3 mm, and the ratio of the length L to the cross-sectional area S of the acoustic duct satisfies 1.6 / mm < L / S < 9 / mm; A closed cavity, the outlet of the acoustic duct communicating with the closed cavity, the sound transmitted from the outlet being enclosed within the closed cavity and isolated from the sound transmitted from the front sound-emitting area.

2. The loudspeaker module according to claim 1, wherein The cross-sectional shape of the acoustic duct is circular or polygonal.

3. The loudspeaker module according to claim 1, characterized in that The acoustic duct is disposed within the rear sound cavity, the acoustic duct is disposed along the inner edge of the housing, and the acoustic duct fits against the inner edge of the housing.

4. The loudspeaker module according to claim 3, wherein, A part of the housing structure for forming the rear sound cavity forms the acoustic duct.

5. The loudspeaker module according to claim 4, characterized in that, The acoustic duct and the housing are integrally formed by an injection molding method.

6. The loudspeaker module according to claim 1, wherein The wall thickness of the acoustic duct is 0.3 - 0.7 mm.

7. The loudspeaker module according to claim 1, wherein The material of the acoustic duct is a glass fiber reinforced composite material.

8. An electronic product, characterized in that, Including the speaker module according to any one of claims 1 - 7; The speaker module is installed within the housing of the electronic product, and the front sound-emitting area is opposite to the sound outlet hole of the housing; The housing forms the closed cavity, and the outlet of the acoustic duct communicates with the closed cavity.

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