Electroacoustic conversion structure

Abstract

The present application provides an electroacoustic conversion structure, comprising: a base, having a cavity; a driving mechanism, comprising an annular fixing portion around a first direction and fixed on the base, and first driving arm portions and second driving arm portions separately formed in the fixing portion, wherein the fixing portion has a first end and a second end which are arranged opposingly in a second direction, the first driving arm portions extend from the first end of the fixing portion toward the second end of the fixing portion, and the second driving arm portions extend from the second end of the fixing portion toward the first end of the fixing portion; and a diaphragm, covering one opening, wherein the diaphragm comprises an annular edge portion around the first direction and fixed on the fixing portion, a main body portion located at the center of the edge portion, and a connecting portion elastically connecting the edge portion and the main body portion, and two ends of the main body portion in the second direction are respectively fixed to the tail ends of the first driving arm portions and the tail ends of the second driving arm portions. The electroacoustic conversion structure of the present application can generate a higher sound pressure level.

Description

An electro-acoustic conversion structure TECHNICAL FIELD

[0001] The present application relates to the field of electro-acoustic conversion, in particular to an electro-acoustic conversion structure. BACKGROUND

[0002] In the related art, as shown in FIG. 1, an electro-acoustic conversion structure 200 includes a base 210, a driver 220, and a diaphragm 230. The base 210 has a cavity 211, the driver 220 has a suspension arm 221 with one end fixed to the base 210 and the other end suspended above the cavity 211, and the diaphragm 230 is fixed to the suspended end of the suspension arm 221. Under the excitation of an electrical signal, the suspension arm 221 vibrates up and down, driving the diaphragm 230 to move together, generating sound pressure.

[0003] However, due to the short length of the suspension arm of the miniaturized electro-acoustic conversion structure, it is difficult to obtain a very high sound pressure level (SPL).

[0004] Therefore, it is necessary to provide an electro-acoustic conversion structure that can improve the sound pressure level. TECHNICAL PROBLEM

[0005] The purpose of the present application is to provide an electro-acoustic conversion structure to solve the technical problem of low sound pressure level in the prior art. TECHNICAL SOLUTION

[0006] The present application provides an electro-acoustic conversion structure, comprising:

[0007] a base having a cavity, the cavity having two openings oppositely arranged in a first direction;

[0008] a driving mechanism including a ring-shaped fixed portion surrounding the first direction and fixed to the base, and a first driving arm portion and a second driving arm portion respectively formed in the fixed portion, the fixed portion having a first end and a second end oppositely arranged in a second direction perpendicular to the first direction, the first driving arm portion extending from the first end of the fixed portion to near the second end of the fixed portion, and the second driving arm portion extending from the second end of the fixed portion to near the first end of the fixed portion; and

[0009] a diaphragm covering one of the openings, the diaphragm including a ring-shaped edge portion surrounding the first direction and fixed to the fixed portion, a main body portion located at the center of the edge portion, and a connecting portion elastically connecting the edge portion and the main body portion, both ends of the main body portion in the second direction being fixed to the ends of the first driving arm portion and the second driving arm portion, respectively.

[0010] Preferably, the connecting portion is a folded ring structure with the middle portion protruding towards the direction away from the base.

[0011] Preferably, the connecting portion comprises a plurality of spring arms arranged around the first direction at intervals, one end of each of the spring arms being connected to the edge portion, and the other end of each of the spring arms being connected to the main body portion.

[0012] Preferably, the connecting portion comprises at least two concave portions arranged coaxially around the first direction, and a convex portion connecting two adjacent concave portions, the concave portions being recessed relative to the main body portion towards the base.

[0013] Preferably, the electro-acoustic conversion structure further comprises a rigidity adjusting plate member covering a side of the main body portion close to the opening, for improving the rigidity of the main body portion.

[0014] Preferably, the driving mechanism comprises a plurality of the first driving arm portions and a plurality of the second driving arm portions, the number of the first driving arm portions being the same as the number of the second driving arm portions, the first driving arm portions and the second driving arm portions being arranged alternately at intervals in a third direction perpendicular to the first direction and the second direction.

[0015] Preferably, the driving mechanism further comprises a first spring portion and a second spring portion.

[0016] The end of the first driving arm portion is connected to the second end of the fixed portion through the first spring portion.

[0017] The end of the second driving arm portion is connected to the first end of the fixed portion through the second spring portion.

[0018] Preferably, the driving mechanism comprises, in order from the base in a direction away from the base, a support layer, a first electrode layer, a piezoelectric layer, and a second electrode layer, the support layer being connected to the base.

[0019] Preferably, the driving mechanism further comprises a passivation layer, the passivation layer being arranged on a side of the second electrode layer away from the piezoelectric layer.

[0020] Preferably, the electro-acoustic conversion structure further comprises a frame around the first direction, a first transmission member, and a second transmission member, the frame being used for connecting the edge portion and the fixed portion, the first transmission member being used for connecting the end of the first driving arm portion and the main body portion, and the second transmission member being used for connecting the end of the second driving arm portion and the main body portion. Advantages

[0021] The application has the beneficial effects that: the electro-acoustic conversion structure comprises a base having a cavity with two openings oppositely arranged in a first direction; a driving mechanism comprising a ring-shaped fixed part surrounding the first direction and fixed to the base, and a first driving arm part and a second driving arm part respectively formed in the fixed part, the fixed part having a first end and a second end oppositely arranged in a second direction perpendicular to the first direction, the first driving arm part extending from the first end of the fixed part to near the second end of the fixed part, and the second driving arm part extending from the second end of the fixed part to near the first end of the fixed part; and a diaphragm covering one of the openings, the diaphragm comprising a ring-shaped edge part surrounding the first direction and fixed to the fixed part, a main body part at the center of the edge part, and a connecting part elastically connecting the edge part and the main body part, and the two ends of the main body part in the second direction are respectively fixed to the end of the first driving arm part and the end of the second driving arm part. In this way, the length of the first driving arm part and the second driving arm part in the second direction can be maximized without increasing the volume of the electro-acoustic conversion structure, thereby effectively increasing the movement amplitude of the end of the first driving arm part and the end of the second driving arm part in the first direction, and further pushing more air to generate higher sound pressure level. BRIEF DESCRIPTION OF DRAWINGS

[0022] FIG. 1 is a schematic diagram of a cross-sectional structure of an electro-acoustic conversion structure in the related art;

[0023] FIG. 2 is a schematic diagram of a cross-sectional structure of another electro-acoustic conversion structure in the related art;

[0024] FIG. 3 is a schematic diagram of a second-order vibration mode of the electro-acoustic conversion structure shown in FIG. 2;

[0025] FIG. 4 is a schematic diagram of a three-dimensional structure of an electro-acoustic conversion structure according to an embodiment of the application;

[0026] FIG. 5 is an exploded view of FIG. 4;

[0027] FIG. 6 is an exploded view of FIG. 4;

[0028] FIG. 7 is a cross-sectional view of FIG. 4;

[0029] FIG. 8 is a schematic diagram of a first-order vibration mode of the electro-acoustic conversion structure shown in FIG. 4;

[0030] FIG. 9 is a schematic diagram of a second-order vibration mode of the electro-acoustic conversion structure shown in

[0031] FIG. 10 is a schematic diagram of a three-dimensional structure of an electro-acoustic conversion structure according to another embodiment of the application;

[0032] FIG. 11 is a cross-sectional view of FIG. 10;

[0033] FIG. 12 is a schematic diagram of a diaphragm structure in the electro-acoustic conversion structure shown in FIG. 10;

[0034] Fig. 13 is a perspective view of an electro-acoustic transducing structure according to an embodiment of the present application;

[0035] Fig. 14 is a sectional view of Fig. 13;

[0036] Fig. 15 is a sectional view of an electro-acoustic transducing structure according to an embodiment of the present application;

[0037] Fig. 16 is a sectional view of an electro-acoustic transducing structure according to an embodiment of the present application;

[0038] Fig. 17 is a sectional view of Fig. 16 without a diaphragm;

[0039] Fig. 18 is a sectional view of Fig. 16 without a diaphragm. Embodiments of the present application

[0040] The present application will be further described with reference to the drawings and embodiments.

[0041] Referring to FIGS. 4-18, an electro-acoustic conversion structure 100 is provided, which includes a base 110, a driving mechanism 120, and a diaphragm 130. The base 110 has a cavity 111 with two openings oppositely arranged in a first direction. The driving mechanism 120 includes a fixed portion 121, a first driving arm portion 122, and a second driving arm portion 123. The fixed portion 121 is fixed to the base 110, and the fixed portion 121 is annular in shape around the first direction. The fixed portion 121 has a first end 121a and a second end 121b oppositely arranged in a second direction, which is perpendicular to the first direction. The first driving arm portion 122 is formed in the fixed portion 121, a first end 122a of the first driving arm portion 122 is fixed to the first end 121a of the fixed portion 121, and a second end 122b of the first driving arm portion 122 extends to be close to the second end 121b of the fixed portion 121 along the second direction. The second driving arm portion 123 is formed in the fixed portion 121, a first end 123a of the second driving arm portion 123 is fixed to the second end 121b of the fixed portion 121, and a second end 123b of the second driving arm portion 123 extends to be close to the first end 121a of the fixed portion 121 along the second direction. The diaphragm 130 covers one of the openings, and the diaphragm 130 includes an edge portion 131, a main body portion 132, and a connecting portion 133. The edge portion 131 is fixed to the fixed portion 121, and the edge portion 131 is annular in shape around the first direction. The main body portion 132 is located at the center of the edge portion 131, and the main body portion 132 has a third end 132a and a fourth end 132b oppositely arranged in the second direction. The third end 132a of the main body portion 132 is fixed to the second end 122b of the first driving arm portion 122, and the fourth end 132b of the main body portion 132 is fixed to the second end 123b of the second driving arm portion 123. The connecting portion 133 is used to elastically connect the edge portion 131 and the main body portion 132, so that the main body portion 132 can move along the first direction under the action of the first driving arm portion 122 and the second driving arm portion 123.

[0042] In the present embodiment, the first driving arm portion 122 and the second driving arm portion 123 respectively extend to be close to the main body portion 132 along the second direction. The length of the first driving arm portion 122 and the second driving arm portion 123 in the second direction can be maximized without increasing the volume of the electro-acoustic conversion structure 100, thereby effectively increasing the movement amplitude of the second end 122b of the first driving arm portion 122 and the second end 123b of the second driving arm portion 123 in the first direction, and further pushing a larger volume of air to generate a higher sound pressure level.

[0043] As an example, the first direction can be the Z direction.

[0044] In the embodiment, please refer to FIG. 8, under the driving of the electrical signal, the end 122b of the first driving arm 122 and the end 123b of the second driving arm 123 can move up and down along the first direction. In the first order vibration mode, since the embodiment greatly extends the length of the first driving arm 122 and the second driving arm 123 in the second direction compared with the related art shown in FIG. 1, the movement amplitude of the end 122b of the first driving arm 122 and the end 123b of the second driving arm 123 along the first direction also significantly increases, and since the end 122b of the first driving arm 122 and the end 123b of the second driving arm 123 will conduct the movement to the diaphragm 130, the movement amplitude of the diaphragm 130 in the first direction also significantly increases, so that the chip of the same size can push a larger volume of air to generate a higher sound pressure level.

[0045] In another related art, please refer to FIG. 2, the electro-acoustic conversion structure 300 includes a base 310, a driver 320 and a diaphragm 330. The base 310 has a cavity 311, the driver 320 includes two opposite extending cantilevers 321, one end of each cantilever 321 is fixed to the base 310 and the other end is suspended, and the diaphragm 330 is fixed to the fixed end of the cantilever 321 through a transmission member. Under the excitation of the electrical signal, the suspended end of the cantilever 321 vibrates up and down to generate sound pressure. However, in the second order vibration mode, please refer to FIG. 3, whether in the first vibration state shown in 3(a) or in the second vibration state shown in 3(b), the cantilever 321 will appear a form that a part moves upward and a part moves downward, and the volume of air pushed upward and the volume of air pushed downward will partially cancel out, resulting in a decrease in the total volume of air pushed by the diaphragm 330, and thus a smaller sound pressure level.

[0046] FIG. 9 is a state where the end 122b of the first driving arm 122 and the end 123b of second driving arm 123 are in a downward state under the driving of the electrical signal when the embodiment is in the first vibration state of the second order vibration mode. However, since the driving mechanism 120 is covered by the diaphragm 130, the edge of the main body 132 of the diaphragm 130 will translate with the edge of the main body 132 or the main body 132 will be bent into an arch shape as shown in FIG. 9 under the downward movement of the end 122b of the first driving arm 122 and the end 123bof the second driving arm 123, thereby avoiding the problem of a decrease in the total volume of air pushed by the diaphragm in the related art shown in FIG. 2. It can be understood that in the embodiment, whether the main body 132 will translate with the edge of the main body 132 or the main body 132 will be curved into an arch shape depends on the stiffness of the main body 132.

[0047] In some embodiments, referring to FIGS. 4-11 and 13-17, the electro-acoustic transducing structure 100 further comprises a frame 140, a first transmission component 151 and a second transmission component 152. The frame 140 is disposed around the first direction, and is disposed between the edge portion 131 and the fixing portion 121 in the first direction, the edge portion 131 being connected to the fixing portion 121 through the frame 140. The first transmission component 151 is disposed between the end 122b of the first driving arm portion 122 and the third end 132a of the main body portion 132 in the first direction, the third end 132a of the main body portion 132 being connected to the end 122b of the first driving arm portion 122 through the first transmission component 151. The second transmission component 152 is disposed between the end 123b of the second driving arm portion 123 and the fourth end 132b of the main body portion 132 in the first direction, the fourth end 132b of the main body portion 132 being connected to the end 123b of the second driving arm portion 123 through the second transmission component 152.

[0048] In the present embodiment, the diaphragm 130 is connected to the driving mechanism 120 through the frame 140, the first transmission component 151 and the second transmission component 152 in the first direction, so that the distance between the diaphragm 130 and the driving mechanism 120 in the first direction can be increased, and interference between the driving mechanism 120 and the diaphragm 130 during vibration can be avoided.

[0049] In some embodiments, the connecting portion 133 is a flexible structure, so that the main body portion 132 can vibrate with the first driving arm portion 122 and the second driving arm portion 123 relative to the edge portion 131 in the first direction.

[0050] As an embodiment, referring to the embodiments shown in FIGS. 4-9, the embodiment shown in FIG. 15 and the embodiment shown in FIG. 16, the connecting portion 133 is configured as a folded ring structure. As an example, the connecting portion 133 can be a folded ring structure in which the middle portion protrudes in the first direction away from the base 110.

[0051] As an embodiment, referring to the embodiments shown in FIGS. 10-12, the connecting portion 133 comprises a plurality of spring arms 1331, all of which are disposed at intervals around the first direction. One end of each spring arm 1331 is connected to the edge portion 131, and the other end of each spring arm 1331 is connected to the main body portion 132.

[0052] As an example, referring to FIGS. 10-12, the main body 132 and the edge portion 131 are square structures with mutually imitated outer contours, the diagonals of the main body 132 and the edge portion 131 coincide, the edge portion of the main body 132 is connected to the corresponding edge portion of the edge portion 131 through two spring arms 1331, and the two spring arms 1331 on the same edge portion are symmetrically arranged. Each spring arm 1331 includes a first connecting segment 1332, a second connecting segment 1333, a third connecting segment 1334, a fourth connecting segment 1335, and a fifth connecting segment 1336 connected in sequence. Among them, the first connecting segment 1332 and the fifth connecting segment 1336 are parallel to the diagonal of the diaphragm 130, and the first connecting segment 1332 is connected to the main body 132 and arranged close to the diagonal, the fifth connecting segment 1336 is connected to the edge portion 131 and arranged close to the diagonal, the second connecting segment 1333 and the fourth connecting segment 1335 are parallel to the edge portion where the spring arm 1331 is located, and the third connecting segment 1334 is perpendicular to the edge portion where the spring arm 1331 is located.

[0053] As an embodiment, referring to the embodiment shown in FIGS. 13-14, the connecting portion 133 includes a concave portion and a convex portion 1339, wherein the concave portion is at least two, each concave portion surrounds the first direction, and all the concave portions are coaxially arranged, the convex portion 1339 is used to connect the adjacent two concave portions into one, and the concave portion is recessed relative to the main body 132 towards the base 110.

[0054] As an example, referring to FIG. 14, the connecting portion 133 can include a first concave portion 1337, a second concave portion 1338, and a convex portion 1339, wherein the first concave portion 1337 is arranged around the outer peripheral edge of the main body 132, the convex portion 1339 is arranged around the outer peripheral edge of the first concave portion 1337, the second concave portion 1338 is arranged around the outer peripheral edge of the convex portion 1339, and the edge portion 131 is arranged around the outer peripheral edge of the second concave portion 1338.

[0055] It should be noted that in other embodiments, the connecting portion 133 can also have other structures, which can be set according to actual conditions and will not be described here.

[0056] In some embodiments, referring to FIG. 15, the electro-acoustic conversion structure 100 further includes a stiffness adjusting plate 160. The stiffness adjusting plate 160 can be arranged on the side of the main body 132 close to the base 110 in the first direction, and the stiffness of the stiffness adjusting plate 160 is greater than the stiffness of the main body 132, so as to effectively improve the stiffness of the main body 132, so that the diaphragm 130 can vibrate in a predetermined vibration mode. It can be understood that the specific stiffness of the stiffness adjusting plate 160 can be set according to actual conditions and will not be described here.

[0057] In some embodiments, referring to FIGS. 5 and 18, the driving mechanism 120 includes a plurality of first driving arms 122 and a plurality of second driving arms 123, and the number of the first driving arms 122 is equal to the number of the second driving arms 123, the length of the first driving arms 122 in the second direction is equal to the length of the second driving arms 123 in the second direction, and the first driving arms 122 and the second driving arms 123 are alternately and spacedly arranged in a third direction perpendicular to the first direction and the second direction. The ends 122b of the first driving arms 122 are respectively connected to the third end 132a of the main body 132, and the ends 123b of the second driving arms 123 are respectively connected to the fourth end 132b of the main body 132.

[0058] For example, referring to FIGS. 5 and 18, the driving mechanism 120 can include two first driving arms 122 and two second driving arms 123. It should be noted that in other embodiments, the driving mechanism 120 can also include other numbers of first driving arms 122 and second driving arms 123, which can be set according to actual conditions, and will not be described here.

[0059] In some embodiments, referring to FIGS. 16 to 18, the driving mechanism 120 further includes a spring portion 124, which is divided into a first spring portion 124a and a second spring portion 124b. The ends 122b of the first driving arms 122 are connected to the second end 121b of the fixed portion 121 through the first spring portion 124a. The ends 123b of the second driving arms 123 are connected to the first end 121a of the fixed portion 121 through the second spring portion 124b.

[0060] In the present embodiment, by providing the first spring portion 124a and the second spring portion 124b, the large harmonic distortion of the sound caused by the large motion amplitude of the ends 122b of the first driving arms 122 and the ends 123b of the second driving arms 123 can be avoided, and the problems such as breakage of the first driving arms 122 and the second driving arms 123 caused by excessive deformation of the first driving arms 122 and the second driving arms 123 can be effectively avoided.

[0061] For example, referring to FIG. 18, the spring portion 124 can include two spring structures 1241 symmetrically arranged about the central axis of the corresponding driving arm. The spring structure 1241 includes a first elastic segment 1242, a second elastic segment 1243 and a third elastic segment 1244 connected in sequence. Among them, the first elastic segment 1242 and the third elastic segment 1244 are parallel to the second direction, the second elastic segment 1243 is parallel to the third direction, the first elastic segment 1242 is connected to the end of the corresponding driving arm, and the third elastic segment 1244 is connected to the fixed portion 121.

[0062] In some embodiments, referring to FIG. 6, the driving mechanism 120 comprises, in sequence in the first direction away from the base 110, a support layer 125, a first electrode layer 126, a piezoelectric layer 127, and a second electrode layer 128, and the support layer 125 is connected to the base 110.

[0063] As an embodiment, referring to FIG. 6, the driving mechanism 120 further comprises a passivation layer 129, and the passivation layer 129 is arranged on the side of the second electrode layer 128 away from the piezoelectric layer 127.

[0064] As an example, referring to FIG. 6, the support layer 125 can comprise, in sequence in the first direction away from the base 110, a first support layer 1251 and a second support layer 1252. The first support layer 1251 is a frame structure, and the first support layer 1251 is connected to the base 110. The first support layer 1251, the second support layer 1252, the first electrode layer 126, the piezoelectric layer 127, and the second electrode layer 128 jointly form the fixed part 121. The second support layer 1252, the first electrode layer 126, the piezoelectric layer 127, and the second electrode layer 128 jointly form the first driving arm part 122 and the second driving arm part 123.

[0065] The above only describes the embodiments of the present application, and it should be pointed out that, for those skilled in the art, improvements can be made without departing from the inventive concept of the present application, and these all belong to the protection scope of the present application.

Claims

1. An electroacoustic conversion structure, characterized in that, include: The base has a cavity having two openings disposed opposite each other in a first direction; The driving mechanism includes an annular fixing portion surrounding the first direction and fixed to the base, and a first driving arm portion and a second driving arm portion respectively formed within the fixing portion. The fixing portion has a first end and a second end disposed opposite to each other in a second direction perpendicular to the first direction. The first driving arm portion extends from the first end of the fixing portion to the second end near the fixing portion, and the second driving arm portion extends from the second end of the fixing portion to the first end near the fixing portion. A diaphragm covering one of the openings, the diaphragm including an annular edge portion surrounding the first direction and fixed to the fixing portion, a main body portion located at the center of the edge portion, and a connecting portion elastically connecting the edge portion and the main body portion, the two ends of the main body portion in the second direction being fixed to the ends of the first drive arm portion and the second drive arm portion, respectively.

2. The electroacoustic conversion structure as described in claim 1, characterized in that, The connecting part is a folded ring structure with a central protrusion pointing away from the base.

3. The electroacoustic conversion structure as described in claim 1, characterized in that, The connecting portion includes a plurality of spring arms spaced apart around the first direction, one end of each spring arm being connected to the edge portion and the other end of each spring arm being connected to the main body portion.

4. The electroacoustic conversion structure as described in claim 1, characterized in that, The connecting portion includes at least two recesses arranged coaxially around the first direction, and a protrusion connecting two adjacent recesses into one, wherein the recesses are recessed toward the base relative to the main body portion.

5. The electroacoustic conversion structure as described in claim 1, characterized in that, The electroacoustic conversion structure also includes a stiffness adjustment plate, which covers the side of the main body near the opening to improve the stiffness of the main body.

6. The electroacoustic conversion structure as described in claim 1, characterized in that, The drive mechanism includes a plurality of first drive arms and a plurality of second drive arms, the number of first drive arms being the same as the number of second drive arms, and the first drive arms and the second drive arms being alternately spaced in a third direction perpendicular to the first direction and the second direction.

7. The electroacoustic conversion structure as described in claim 1, characterized in that, The drive mechanism further includes a first spring section and a second spring section; The end of the first drive arm is connected to the second end of the fixed part via the first spring part; The end of the second drive arm is connected to the first end of the fixed part via the second spring part.

8. The electroacoustic conversion structure as described in claim 1, characterized in that, The driving mechanism includes a support layer, a first electrode layer, a piezoelectric layer, and a second electrode layer arranged sequentially in the first direction away from the base, and the support layer is connected to the base.

9. The electroacoustic conversion structure as described in claim 8, characterized in that, The drive mechanism further includes a passivation layer disposed on the side of the second electrode layer away from the piezoelectric layer.

10. The electroacoustic conversion structure as described in claim 1, characterized in that, The electroacoustic conversion structure further includes a frame surrounding the first direction, a first transmission component, and a second transmission component. The frame is used to connect the edge portion and the fixed portion. The first transmission component is used to connect the end of the first drive arm portion and the main body portion. The second transmission component is used to connect the end of the second drive arm portion and the main body portion.

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