阅读说明：本技术 发声装置的振膜以及发声装置 (Sound generating device's vibrating diaphragm and sound generating device ) 是由 王述强 凌风光 李春 刘春发 于 2019-10-31 设计创作，主要内容包括：本发明公开了一种用于发声装置的振膜以及发声装置。所述振膜包括异戊橡胶膜层。所述异戊橡胶膜层为异戊二烯聚合物通过交联反应制备而成的膜层。所述异戊二烯聚合物以下列通式表示：<Image he="211" wi="700" file="DDA0002256727190000011.GIF" imgContent="drawing" imgFormat="GIF" orientation="portrait" inline="no"></Image>异戊橡胶是由异戊二烯单体聚合制得的合成橡胶。相对于工程塑料,异戊橡胶具有更好的回弹特性。在常温下,异戊橡胶呈现高弹态,在较大的应变范围内都不会发生屈服应变。使用该材料制成振膜不仅具有更大的有效振动范围,并且能使发声装置在相同的驱动功率下的响度更高。(The invention discloses a vibrating diaphragm for a sound generating device and the sound generating device. The vibrating diaphragm comprises an isoprene rubber film layer. The isoprene rubber membrane layer is a membrane layer prepared by isoprene polymer through a crosslinking reaction. The isoprene polymer is represented by the following general formula: isoprene rubber is a synthetic rubber made by polymerizing isoprene monomers. Compared with engineering plastics, the isoprene rubber has better rebound property. At normal temperature, the isoprene rubber is in a high elastic state, and yield strain can not occur in a large strain range. The diaphragm made of the material has a larger effective vibration range, and the loudness of the sound generating device under the same driving power is higher.)

1. The utility model provides a sound generating mechanism's vibrating diaphragm which characterized in that: the diaphragm comprises an isoprene rubber film layer, wherein the isoprene rubber film layer is a film layer prepared by isoprene polymer through a cross-linking reaction, and the isoprene polymer is represented by the following general formula:

2. the diaphragm of claim 1, wherein: the isoprene polymer includes at least one of a cis-1, 4-structure and a trans-1, 4-structure.

3. The diaphragm of claim 2, wherein: the isoprene polymer comprises a cis-1, 4-structure and a trans-1, 4-structure, wherein the mass content of the cis-1, 4-structure is 90-99%.

4. The diaphragm of claim 1, wherein: the rubber composition further comprises a vulcanizing agent which is added into the isoprene polymer during the crosslinking reaction, and the vulcanizing agent comprises at least one of sulfur, peroxide and reactive resin.

5. The diaphragm of claim 1, wherein: the isoprene rubber composite material further comprises a reinforcing agent, wherein the reinforcing agent is added into the isoprene polymer during crosslinking reaction, and the reinforcing agent comprises at least one of carbon black, silicon dioxide, calcium carbonate, barium sulfate, organic montmorillonite and unsaturated carboxylic acid metal salt.

6. The diaphragm of claim 1, wherein: the isoprene rubber composition further comprises an anti-aging agent, wherein the anti-aging agent is added into the isoprene polymer during crosslinking reaction, and comprises at least one of anti-aging agent N-445, anti-aging agent 246, anti-aging agent 4010, anti-aging agent SP, anti-aging agent RD, anti-aging agent ODA, anti-aging agent OD and anti-aging agent WH-02.

7. The diaphragm of claim 1, wherein: and the internal release agent is added into the isoprene polymer during the crosslinking reaction, and comprises at least one of stearic acid and stearate, octadecyl amine and alkyl phosphate, and alpha-octadecyl-omega-hydroxyl polyoxyethylene phosphate.

8. The diaphragm of claim 1, wherein: the thickness of the diaphragm is 10-200 μm.

9. The diaphragm of claim 1, wherein: the hardness of the diaphragm is 20-90A.

10. The diaphragm of claim 1, wherein: the elongation at break of the isoprene rubber film layer is more than 100%, and the loss factor of the isoprene rubber film layer is more than 0.06.

11. The diaphragm according to any one of claims 1 to 10, wherein: the diaphragm is prepared by adopting a compression molding mode, an injection molding mode or an air pressure molding mode.

12. A sound generating device, characterized by: comprising a magnetic circuit and a vibration system cooperating with the magnetic circuit, the vibration system comprising a diaphragm according to any of claims 1-11.

Technical Field

The invention relates to the technical field of electroacoustic conversion, in particular to a vibrating diaphragm of a sound generating device and the sound generating device.

Background

The existing micro loudspeaker diaphragm mostly uses high-modulus engineering plastics (such as PEEK) as the diaphragm raw material; the diaphragm may be a composite material of an engineering plastic film and a damping adhesive film (e.g., acrylic adhesive, silica gel, etc.). The diaphragm usually needs to be shaped by hot pressing, air pressure, or other heating methods to form a predetermined corrugated structure. The corrugated rim structure is used for providing the compliance of the vibrating diaphragm so as to adjust the vibration state of the vibrating diaphragm.

The existing polymer diaphragm can have a better vibration state within a certain vibration range after being molded into a preset shape. Since engineering plastics have a high crosslinking density, yield strain tends to occur at a relatively low strain although the elastic modulus is high. When the vibration amplitude of the vibrating diaphragm is too large or external force is applied, the corrugated ring shape of the vibrating diaphragm is extremely easy to bend irreversibly, the symmetry of the compliance of the vibrating diaphragm changes, and the loudspeaker generates abnormal sound or directly fails.

Therefore, a new technical solution is needed to solve at least one of the above technical problems.

Disclosure of Invention

The invention aims to provide a new technical scheme of a vibrating diaphragm of a sound production device.

According to a first aspect of the invention, a diaphragm for a sound generating device is provided. The diaphragm comprises an isoprene rubber film layer, wherein the isoprene rubber film layer is a film layer prepared by isoprene polymer through a cross-linking reaction, and the isoprene polymer is represented by the following general formula:

optionally, the isoprene polymer comprises at least one of a cis-1, 4-structure and a trans-1, 4-structure.

Optionally, the isoprene polymer comprises a cis-1, 4-structure and a trans-1, 4-structure, wherein the mass content of the cis-1, 4-structure is 90-99%.

Optionally, the rubber composition further comprises a vulcanizing agent which is added to the isoprene polymer when the crosslinking reaction is carried out, and the vulcanizing agent comprises at least one of sulfur, peroxide and reactive resin.

Optionally, a reinforcing agent is further included, the reinforcing agent being added to the isoprene polymer when the crosslinking reaction is performed, and the reinforcing agent includes at least one of carbon black, silica, calcium carbonate, barium sulfate, organic montmorillonite, and metal salt of unsaturated carboxylic acid.

Optionally, the rubber composition further comprises an anti-aging agent, wherein the anti-aging agent is added into the isoprene polymer during crosslinking reaction, and the anti-aging agent comprises at least one of anti-aging agent N-445, anti-aging agent 246, anti-aging agent 4010, anti-aging agent SP, anti-aging agent RD, anti-aging agent ODA, anti-aging agent OD and anti-aging agent WH-02.

Optionally, the isoprene rubber composition further comprises an internal release agent which is added to the isoprene polymer when the crosslinking reaction is carried out, wherein the internal release agent comprises at least one of stearic acid and stearate, octadecyl amine and alkyl phosphate, and alpha-octadecyl-omega-hydroxypolyoxyethylene phosphate.

Optionally, the thickness of the diaphragm is 10-200 μm.

Optionally, the diaphragm has a stiffness of 20-90A.

Optionally, the elongation at break of the isoprene rubber membrane layer is 100% or more, and the loss factor of the isoprene rubber membrane layer is 0.06 or more.

Optionally, the diaphragm is prepared by compression molding, injection molding or air pressure molding.

According to another embodiment of the present disclosure, a sound generating device is provided. The sound production device comprises a magnetic circuit system and a vibration system matched with the magnetic circuit system, wherein the vibration system comprises the vibrating diaphragm.

According to one embodiment of the present disclosure, the isoprene rubber is a synthetic rubber prepared by polymerizing isoprene monomers. Compared with engineering plastics, the isoprene rubber has better rebound property. At normal temperature, the isoprene rubber is in a high elastic state, and yield strain can not occur in a large strain range. The diaphragm made of the material has a larger effective vibration range, and the loudness of the sound generating device under the same driving power is higher.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is a graph of hardness of isoprene rubber as a function of the amount of reinforcing agent added according to one embodiment of the present disclosure.

Fig. 2 is a graph of elongation at break of isoprene rubber as a function of the amount of reinforcing agent added according to one embodiment of the disclosure.

FIG. 3 is a graph of impedance versus response frequency for diaphragms of different stiffness according to one embodiment of the present disclosure.

Fig. 4 is a total harmonic distortion test curve of a sound generating device using a diaphragm according to an embodiment of the present disclosure and a sound generating device using a conventional diaphragm.

FIG. 5 is a stress-strain curve of a diaphragm and an engineering plastic diaphragm according to one embodiment of the present disclosure.

Fig. 6 is a graph showing the variation of the sensitivity with frequency of a sound generating device using a diaphragm according to an embodiment of the present disclosure and a sound generating device using an engineering plastic diaphragm.

Fig. 7-8 are cross-sectional views of composite diaphragms according to embodiments of the present disclosure.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of the components and steps, the numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof is not required in subsequent figures.

According to one embodiment of the present disclosure, a diaphragm for a sound generating apparatus is provided. The sound generating device is a miniature sound generating device, for example, a miniature sound generating device used in portable equipment such as earphones, mobile phones, tablet computers and notebook computers.

The vibrating diaphragm comprises an isoprene rubber film layer. The isoprene rubber membrane layer is a membrane layer prepared by isoprene polymer through a crosslinking reaction. The isoprene polymer is represented by the following general formula:

for example, the diaphragm is a flat diaphragm or a corrugated diaphragm. The edge portion is arranged around the edge portion.

In the disclosed embodiments, the isoprene rubber is a synthetic rubber prepared by polymerizing isoprene monomers. Compared with engineering plastics, the isoprene rubber has better rebound property. At normal temperature, the isoprene rubber is in a high elastic state, and yield strain can not occur in a large strain range. The diaphragm made of the material has a larger effective vibration range, and the loudness of the sound generating device under the same driving power is higher.

In addition, due to good rebound resilience, the vibrating diaphragm made of the material is not easy to deform due to overlarge vibration amplitude or external force influence. Therefore, the vibrating diaphragm can vibrate in a larger range during working, and the vibrating diaphragm sound generating device has higher sensitivity.

For example, the diaphragm is a single-layer film. The membrane layer is made of isoprene rubber. For example, the material is prepared by compression molding, injection molding or air pressure molding. The preparation method has high molding efficiency and good molding consistency.

The diaphragm may be a composite diaphragm. The composite diaphragm includes a plurality of film layers, for example, two layers, three layers, four layers, five layers, and the like. Wherein at least one membrane layer is made of isoprene rubber, namely an isoprene rubber membrane layer.

Fig. 7 shows a three-layer composite diaphragm, wherein the middle layer is an isoprene rubber film layer 12, and the upper and lower surfaces of the isoprene rubber film layer are respectively compounded with engineering plastic film layers 11.

Fig. 8 shows a five-layer composite diaphragm, in which three engineering plastic film layers 11 are used as a middle layer, an upper surface layer and a lower surface layer of the composite diaphragm, respectively. The two isoprene rubber film layers 12 are alternately arranged among the three engineering plastic film layers 11.

The film layers of the composite diaphragm are combined together in the modes of hot pressing, casting, bonding and the like.

Or the damping rubber layer and the isoprene rubber membrane layer are compounded together. The damping rubber layer has viscosity, and can be more easily compounded with the isoprene rubber film layer.

Of course, the structure of the composite diaphragm is not limited to the above-mentioned embodiments, and those skilled in the art can set the diaphragm according to actual needs.

In one example, the isoprene polymer includes at least one of a cis-1, 4-structure and a trans-1, 4-structure. For example, isoprene polymers include cis-1, 4-structures and/or trans-1, 4-structures in the molecular chain. The cis-1, 4-structure molecular chain is regular, and the molecular chain is soft and smooth and is easy to return to the shape, so that the isoprene rubber has better rebound property. When the mass content of the cis-1, 4-structure is too low, the regularity of the molecular chain of isoprene rubber is reduced, and the rebound resilience of isoprene rubber is affected.

For example, the cis-1, 4-structure is present in an amount of 90 to 99% by mass. Within this range, the isoprene rubber has good resilience properties.

Further, the mass content of the cis-1, 4-structure is 95-99%. Within this range, the isoprene rubber is more excellent in resilience performance.

Of course, the isoprene polymer is not limited to the above examples, and can be selected by those skilled in the art according to actual needs.

In one example, a vulcanizing agent is also included. The vulcanizing agent is added to the isoprene polymer at the time of carrying out a crosslinking reaction. The vulcanizing agent comprises at least one of sulfur, peroxide and reactive resin. The vulcanizing agent enables the molecular chains of the foreign body diene polymer to be crosslinked together, the crosslinking degree of the foreign body diene polymer is gradually increased along with the progress of crosslinking reaction, and the movement of the molecular chains is limited, so that the isoprene rubber obtains enough strength.

For example, the vulcanizing agent is used in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the foreign diene polymer. Within the range, the isoprene rubber has stable quality, high strength, good molding effect and good rebound effect.

Of course, the vulcanizing agent is not limited to the above examples, and can be selected by those skilled in the art according to actual needs.

In one example, a strengthening agent is also included. The reinforcing agent is added to the isoprene polymer when the crosslinking reaction is performed. For example, the reinforcing agent is an inorganic filler in powder form. The reinforcing agent can obviously improve the hardness of the material. The reinforcing agent comprises at least one of carbon black, silicon dioxide, calcium carbonate, barium sulfate, organic montmorillonite and unsaturated carboxylic acid metal salt. The reinforcing agents are uniformly dispersed in the foreign diene polymer, and have good compatibility. The material has excellent reinforcing effect.

Fig. 1 is a graph of hardness of isoprene rubber as a function of the amount of reinforcing agent added according to one embodiment of the present disclosure. Wherein, the solid line is the change curve of the hardness of the isoprene rubber along with the addition amount of the carbon black. The dotted line is the curve of the hardness of isoprene rubber with the addition of white carbon black. The abscissa is the added parts by mass of the reinforcing agent per 100 parts by mass. The ordinate is the shore a hardness.

As shown in FIG. 1, the hardness of isoprene rubber gradually increases with the amount of reinforcing agent added. The same addition amount of the carbon black is better than the reinforcing effect of the white carbon black on the isoprene rubber.

Fig. 2 is a graph of elongation at break of isoprene rubber as a function of the amount of reinforcing agent added according to one embodiment of the disclosure. Wherein the abscissa is the mass part of the reinforcing agent added per 100 mass parts of the foreign-matter diene polymer; the ordinate represents the elongation at break of the foreign rubber formed. Wherein the reinforcing agent is carbon black.

As shown in FIG. 2, the elongation at break of isoprene rubber gradually decreased as the amount of carbon black added increased.

When the amount of the reinforcing agent added is too high, the elongation at break of the isoprene rubber is drastically reduced. Therefore, the flexibility of the isoprene rubber is reduced, the brittleness is increased, and the diaphragm is easy to break. In one example, the reinforcing agent is added in an amount of 5 to 90 parts by mass per 100 parts by mass of the foreign diene polymer. Within this range, the elongation at break of the isoprene rubber formed is 200% or more. The flexibility of the diaphragm is good.

Further, the amount of the reinforcing agent added is 5 to 70 parts. Within this range, the elongation at break of the isoprene rubber formed is 400% or more. The isoprene rubber has good membrane rupture resistance.

When the amount of carbon black added is 100 parts or more, the elongation at break of the isoprene rubber is reduced to 90% or less. In this case, when a large stress is applied, the diaphragm is likely to be broken. The durability of the diaphragm is poor.

Of course, the reinforcing agent is not limited to the above-mentioned embodiments, and those skilled in the art can select the reinforcing agent according to actual needs.

In one example, an anti-aging agent is also included. The antioxidant is added to the isoprene polymer during the crosslinking reaction. The antioxidant comprises at least one of antioxidant N-445, antioxidant 246, antioxidant 4010, antioxidant SP, antioxidant RD, antioxidant ODA, antioxidant OD and antioxidant WH-02. In the using process, the molecular chain of the isoprene rubber is broken to generate free autocatalytic active free radicals along with the prolonging of time, so that the self aging is accelerated. The anti-aging agent can stop the generation of autocatalytic active free radicals in isoprene rubber products. The anti-aging agent can obviously improve the anti-aging performance of isoprene rubber and prolong the service life of isoprene rubber products (such as diaphragms).

If the addition amount of the anti-aging agent is too small, the effect of prolonging the service life of the vibrating diaphragm cannot be achieved; and the mechanical property of the isoprene rubber is reduced because the anti-aging agent cannot be well dissolved with the isoprene polymer and is difficult to uniformly disperse due to excessive addition amount.

In one example, the antioxidant is added in an amount of 0.5 to 10 parts by mass per 100 parts by mass of the isoprene polymer. Within the proportion range, the anti-aging agent can obviously improve the service life and the mechanical property of the isoprene rubber product.

Furthermore, the addition amount of the anti-aging agent is 1-5 parts. Within the range, the isoprene rubber product has longer service life and better mechanical property.

Of course, the antioxidant is not limited to the above-mentioned examples, and can be selected by those skilled in the art according to actual needs.

In one example, an internal mold release agent is also included. The internal mold release agent is added to the isoprene polymer when the crosslinking reaction is performed. The internal mold release agent comprises at least one of stearic acid and stearate, octadecyl amine and alkyl phosphate, and alpha-octadecyl-omega-hydroxyl polyoxyethylene phosphate. The addition of an internal mold release agent to the isoprene polymer enables the in-mold formed rubber article to have reduced adhesion to the mold cavity wall to facilitate mold release.

For example, the internal mold release agent is used in an amount of 0.5 to 5 parts by mass per 100 parts by mass of the isoprene polymer. Within the range, the isoprene rubber product has high demolding speed, good demolding effect and high yield.

In the disclosed embodiments, the isoprene rubber has a lower modulus relative to the engineering plastic. The hardness of the isoprene rubber can be adjusted by adding the reinforcing agent, so that the isoprene rubber has a larger hardness adjusting range. For example, isoprene rubber products have a hardness in the range of 25A to 90A. The 100% modulus of isoprene rubber is positively correlated to its hardness. The higher the stiffness, the higher the 100% modulus of the diaphragm, the higher the F0 of the diaphragm, but when F0 is too high, the loudness of the low frequency of the sound generating device will decrease; conversely, the lower the stiffness, the lower the 100% modulus of elongation of the diaphragm, and the lower the F0 of the diaphragm.

Within the above hardness range, the adjustment range of 100% modulus at room temperature is 0.5 to 50 MPa. In this range, the sound generating device using the diaphragm according to the embodiment of the present disclosure has a low F0, and the low frequency effect of the sound generating device is good.

Further, the hardness range of the isoprene rubber product is 30A-85A. Within the above hardness range, the adjustable range of 100% modulus at room temperature is 1 to 30 MPa.

The F0 of the sound generating device is proportional to the Young modulus and the thickness of the diaphragm material, the change of F0 can be realized by changing the thickness and the Young modulus of the diaphragm, and the specific regulation principle is as follows:

wherein, Mms is the equivalent vibration quality of sound generating mechanism, and Cms is the equivalent compliance of sound generating mechanism:

wherein Cms1 is the elasto-compliance and Cms2 is the diaphragm compliance. When there is no elastic wave design, the equivalent compliance of the sounding device is the compliance of the vibrating diaphragm:

wherein, W is the total width of the bending ring part of the vibrating diaphragm, and t is the thickness of the vibrating diaphragm; dvc is the joint outer diameter of the voice coil on the vibrating diaphragm; e is the Young modulus of the diaphragm material; u is the Poisson's ratio of the diaphragm material.

It can be seen that the F0 of the sound generator is proportional to the modulus and thickness of the diaphragm material. While the modulus of isoprene rubber is proportional to its hardness. Therefore, F0 of the sound emitting device was adjusted by adjusting the hardness of the isoprene rubber.

In order to obtain a full bass and comfortable hearing, the diaphragm should have sufficient stiffness and damping while the sound generator has a low F0. By adjusting the hardness and thickness of the diaphragm, adjustment of F0 of the sound emitting device can be achieved.

In one example, the diaphragm has a stiffness of 20A-90A. The thickness of the diaphragm of the sound generating device is 10-200 μm. For example, when the diaphragm is a single film layer, i.e., an isoprene rubber film layer, the thickness of the film layer is 10 μm to 200 μm.

For example, when the diaphragm is a composite diaphragm, the total thickness of the diaphragm is 10 μm to 200 μm.

Within the range of hardness and thickness, the adjustable range of F0 of the sound generating device can reach 150 Hz and 1500 Hz. In this way, the acoustic performance requirements of most sound generating devices can be met.

Further, the thickness of the diaphragm is 30-120 μm.

FIG. 3 is a graph of impedance versus response frequency for diaphragms of different stiffness according to one embodiment of the present disclosure. The peak position of each curve is the position of F0 of the sound emitting device.

As shown in fig. 3, the higher the stiffness of the diaphragm, the higher the F0 of the diaphragm.

In the embodiment of the disclosure, the molecular chain of the isoprene rubber has a regular structure and is flexible. Compared with engineering plastics, the isoprene rubber has higher damping. The loss factor of the isoprene rubber at room temperature is above 0.06, so the isoprene rubber has excellent damping performance, which makes the diaphragm have lower impedance. The damping of the vibrating diaphragm is improved, the vibration system has strong capability of inhibiting the polarization phenomenon in the vibration process, the vibration consistency is good, and the noise is small.

Further, the loss factor of isoprene rubber at room temperature is 0.1 or more. Within the range, the vibrating diaphragm has stronger polarization inhibiting capability and better vibration consistency.

The sound production device adopting the vibrating diaphragm disclosed by the embodiment of the disclosure has a lower Q value, can effectively inhibit redundant vibration of a vibration system and polarization of the vibration system, and achieves the effect of reducing distortion of the sound production device.

Fig. 4 is a total harmonic distortion test curve of a sound generating device using a diaphragm according to an embodiment of the present disclosure and a sound generating device using a conventional diaphragm. I.e. the THD curve. Wherein, the dotted line is the THD curve of the sound generating device of the vibrating diaphragm implemented by adopting the present disclosure. The solid line is the THD curve of a sound generating device using a conventional diaphragm (e.g., an engineering plastic diaphragm).

As shown in fig. 4, the broken line is entirely located below the solid line. Compared with the sound generating device adopting the conventional vibrating diaphragm, the sound generating device adopting the vibrating diaphragm disclosed by the embodiment of the disclosure has smaller total harmonic distortion. Therefore, the diaphragm of the embodiment of the invention has more excellent polarization suppression capability.

FIG. 5 is a stress-strain curve of a diaphragm and an engineering plastic diaphragm according to one embodiment of the present disclosure. Wherein, the dotted line is a stress-strain curve of the diaphragm of the embodiment of the present disclosure; and the solid line is a stress-strain curve of the engineering plastic diaphragm.

In the disclosed embodiments, the isoprene rubber has excellent toughness. For example, the elongation at break of isoprene rubber is 100% or more. When the sound-generating device is used, the vibrating diaphragm is not easy to break.

Further, the elongation at break of isoprene rubber is 150% or more.

During use, the engineering plastic has an obvious yield point. For example, yield points occur at strains of 1-5%. Due to the existence of the yield point, when the amplitude of the vibrating diaphragm is too large, abnormal phenomena such as membrane folding, membrane breaking and the like are easily generated at the folding ring part. As shown in fig. 5, the diaphragm of the embodiment of the present disclosure has no yield point and is excellent in spring back. This indicates that the diaphragm of the disclosed embodiment has a larger amplitude at the same drive power. Under the condition that the structure is the same except that sound generating mechanism's vibrating diaphragm, the amplitude of the vibrating diaphragm of the sound generating mechanism who uses this vibrating diaphragm is bigger to can send the sound that loudness is bigger.

Fig. 6 is a graph of sensitivity versus frequency (i.e., SPL curve) for a sound-generating device employing a diaphragm according to an embodiment of the present disclosure and a sound-generating device employing an engineering plastic diaphragm. Wherein, the solid line is a change curve of the sensitivity of the sound generating device adopting the vibrating diaphragm of the embodiment of the disclosure along with the frequency; the dotted line is the change curve of the sensitivity of the sound producing device adopting the engineering plastic vibrating diaphragm along with the frequency.

As shown in fig. 6, F0 of the two sound emitting devices substantially coincide. Because the isoprene rubber diaphragm has a larger effective amplitude, the sensitivity of the sound generating device adopting the diaphragm of the embodiment of the disclosure is higher than that of the sound generating device adopting the engineering plastic diaphragm. That is, the sound generating apparatus using the diaphragm of the embodiment of the present disclosure has a higher loudness at the same driving power.

According to another embodiment of the present disclosure, a sound generating device is provided. The sound generating device is a miniature sound generating device, for example, a miniature sound generating device used in portable equipment such as earphones, mobile phones, tablet computers and notebook computers. The sound production device comprises a magnetic circuit system and a vibration system matched with the magnetic circuit system. The vibration system comprises the diaphragm provided by the embodiment of the disclosure.

The sound production device has the characteristics of good durability, small noise and good sound production effect.

Although some specific embodiments of the present invention have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustrative purposes only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.