Electro-acoustic conversion structure

Abstract

The utility model provides an electro-acoustic conversion structure, comprising a base having a cavity; the driving mechanism comprises an annular fixing part which surrounds the first direction and is fixed on the base, and a first driving arm part and a second driving arm part which are respectively formed in the fixing part, the fixing part is provided with a first end and a second end which are oppositely arranged in the second direction, the first driving arm part extends from the first end of the fixing part to the second end close to the fixing part, and the second driving arm part extends from the second end close to the fixing part; the second driving arm part extends from the second end of the fixed part to the first end close to the fixed part; and the vibrating diaphragm covers one of the openings, the vibrating diaphragm comprises an annular edge part which surrounds the first direction and is fixed on the fixed part, a main body part which is positioned in the center of the edge part, and a connecting part which is elastically connected with the edge part and the main body part, and two ends of the main body part in the second direction are respectively fixed with the tail end of the first driving arm part and the tail end of the second driving arm part. The electroacoustic conversion structure of the utility model can generate a higher sound pressure level.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of electric-acoustic conversion, and particularly relates to an electric-acoustic conversion structure.

BACKGROUND

[0002] In the related art, as shown in FIG. 1, an electric-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 one end fixed to the base 210 and the other end suspended above the cavity 211 by a cantilever 221. The diaphragm 230 is fixed to the free end of the cantilever 221. Under the excitation of an electric signal, the cantilever 221 vibrates up and down, driving the diaphragm 230 to move together, generating sound pressure. Figure 1

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

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

SUMMARY

[0005] The utility model aims at providing an electric-acoustic conversion structure to solve the technical problem of low sound pressure level in the prior art.

[0006] The utility model provides an electric-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 an annular 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

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

[0010] Preferably, the connecting part is a folded ring structure with the middle part 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.

[0021] The beneficial effects of this utility model are as follows: The electroacoustic conversion structure of this utility model includes: a base having a cavity with two openings opposite to each other in a first direction; a drive mechanism including an annular fixing part surrounding the first direction and fixed to the base, and a first drive arm and a second drive arm respectively formed within the fixing part; the fixing part having a first end and a second end opposite to each other in a second direction perpendicular to the first direction; the first drive arm extending from the first end of the fixing part to the second end near the fixing part; and the second drive arm extending from the second end of the fixing part to the first end near the fixing part; and a diaphragm covering one of the openings, the diaphragm including an annular edge portion surrounding the first direction and fixed to the fixing part, a main body portion located at the center of the edge portion, and a connecting part elastically connecting the edge portion and the main body portion; the two ends of the main body portion in the second direction are respectively fixed to the ends of the first drive arm portion and the second drive arm portion. Through the above method, the length of the first drive arm portion and the second drive arm portion in the second direction can be maximized without increasing the volume of the electroacoustic conversion structure, thereby effectively increasing the movement amplitude of the ends of the first drive arm portion and the second drive arm portion in the first direction, thereby pushing a larger volume of air and generating a higher sound pressure level. [Attached Image Description]

[0022] Figure 1 This is a schematic diagram of the cross-sectional structure of the electroacoustic conversion structure in the relevant technology;

[0023] Figure 2 This is a schematic diagram of the cross-sectional structure of an electroacoustic conversion structure in another related technology;

[0024] Figure 3 for Figure 2 The diagram shows the second-order vibration mode of the electroacoustic conversion structure.

[0025] Figure 4 This is a three-dimensional structural diagram of the electroacoustic conversion structure according to an embodiment of the present invention;

[0026] Figure 5 for Figure 4 Exploded view;

[0027] Figure 6 for Figure 4 Exploded view;

[0028] Figure 7 for Figure 4 A sectional view;

[0029] Figure 8 for Figure 4 A schematic diagram of the first-order vibration mode of the electroacoustic conversion structure shown.

[0030] Figure 9 for Figure 4The diagram shows the second-order vibration mode of the electroacoustic conversion structure.

[0031] Figure 10 This is a three-dimensional structural diagram of the electroacoustic conversion structure according to an embodiment of the present invention;

[0032] Figure 11 for Figure 10 A sectional view;

[0033] Figure 12 for Figure 10 The diagram shows the diaphragm structure in the electroacoustic conversion structure.

[0034] Figure 13 This is a three-dimensional structural diagram of the electroacoustic conversion structure according to an embodiment of the present invention;

[0035] Figure 14 for Figure 13 A sectional view;

[0036] Figure 15 This is a cross-sectional view of the electroacoustic conversion structure according to an embodiment of the present invention;

[0037] Figure 16 This is a cross-sectional view of the electroacoustic conversion structure according to an embodiment of the present invention;

[0038] Figure 17 for Figure 16 The diagram shown illustrates the cross-sectional structure with the diaphragm removed.

[0039] Figure 18 for Figure 16 The diagram shows the electroacoustic conversion structure with the diaphragm removed.

Detailed Implementation Methods

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

[0041] Please refer to Figures 4 to 18The utility model embodiment provides a kind of electroacoustic conversion structure 100, including pedestal 110, drive mechanism 120 and diaphragm 130.Pedestal 110 has cavity 111, cavity 111 has two openings oppositely arranged in the first direction.Drive mechanism 120 includes fixed part 121, first drive arm part 122 and second drive arm part 123.Fixed part 121 is fixed to pedestal 110, and fixed part 121 is annular structure around the first direction.Fixed part 121 has first end 121a and second end 121b oppositely arranged in the second direction, and the second direction is perpendicular to the first direction.First drive arm part 122 is formed in fixed part 121, and the first end 122a of first drive arm part 122 is fixed to the first end 121a of fixed part 121, and the terminal 122b of first drive arm part 122 extends to the second end 121b close to fixed part 121 along the second direction.Second drive arm part 123 is formed in fixed part 121, and the first end 123a of second drive arm part 123 is fixed to the second end 121b of fixed part 121, and the terminal 123b of second drive arm part 123 extends to the first end 121a close to fixed part 121 along the second direction.Diaphragm 130 covers one of the openings, and diaphragm 130 includes edge part 131, main body part 132 and connecting part 133.Edge part 131 is fixed with fixed part 121, and edge part 131 is annular structure around the first direction.Main body part 132 is located in the center of edge part 131, and main body part 132 has third end 132a and fourth end 132b oppositely arranged in the second direction, and the third end 132a of main body part 132 is fixed with the terminal 122b of first drive arm part 122, and the fourth end 132b of main body part 132 is fixed with the terminal 123b of second drive arm part 123.Connecting part 133 is used for elastically connecting edge part 131 and main body part 132, so that main body part 132 can move along the first direction under the action of first drive arm part 122 and second drive arm part 123.

[0042] In the embodiment, first drive arm part 122 and second drive arm part 123 extend to close to main body part 132 along the second direction respectively, can maximize the length of first drive arm part 122 and second drive arm part 123 in the second direction without increasing the volume of electroacoustic conversion structure 100, to effectively increase the movement amplitude of the terminal 122b of first drive arm part 122 and the terminal 123b of second drive arm part 123 in the first direction, and further push larger volume of air, produce higher sound pressure level.

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

[0044] In the embodiment, please refer to Figure 8As shown, under the drive of an electrical signal, the end 122b of the first drive arm 122 and the end 123b of the second drive arm 123 can move up and down along a first direction. In the first-order vibration mode, since this embodiment is more advanced than... Figure 1 The related technology shown greatly extends the length of the first drive arm 122 and the second drive arm 123 in the second direction. Therefore, the movement amplitude of the end 122b of the first drive arm 122 and the end 123b of the second drive arm 123 along the first direction is also significantly increased. Since the end 122b of the first drive arm 122 and the end 123b of the second drive arm 123 will transmit the motion to the diaphragm 130, the movement amplitude of the diaphragm 130 in the first direction is also significantly increased. Therefore, a chip of the same size can push a larger volume of air and generate a higher sound pressure level.

[0045] In another related technology, please refer to Figure 2 As shown, the electroacoustic conversion structure 300 includes a substrate 310, a driver 320, and a diaphragm 330. The substrate 310 has a cavity 311. The driver 320 includes two opposing cantilever arms 321, one end of each cantilever arm 321 fixed to the substrate 310 and the other end suspended. The diaphragm 330 is fixed to the fixed end of the cantilever arm 321 via a transmission component. Under the excitation of an electrical signal, the suspended end of the cantilever arm 321 vibrates up and down, generating sound pressure. For the second-order vibration mode, please refer to... Figure 3 As shown, whether in the first vibration state shown in 3(a) or the second vibration state shown in 3(b), the cantilever 321 will exhibit a shape where part of it moves upward and part of it moves downward. The volume of air pushed upward and the volume of air pushed downward will partially cancel each other out, resulting in a reduction in the total volume of air pushed by the diaphragm 330, and thus a lower sound pressure level.

[0046] Figure 9 In this embodiment, when in the first vibration state of the second-order vibration mode, under the drive of the electrical signal, the end 122b of the first drive arm 122 and the end 123b of the second drive arm 123 are in a downward state. However, since the drive mechanism 120 is covered with a diaphragm 130, under the downward movement of the end 122b of the first drive arm 122 and the end 123b of the second drive arm 123, the edge of the main body 132 of the diaphragm 130 will either translate with the edge of the main body 132 or be bent into a shape similar to... Figure 9 The arch shape shown avoids the occurrence of Figure 2 The related art shown has the problem of reduced total air volume driven by the diaphragm. It is understood that in this embodiment, whether the main body 132 translates with the edge of the main body 132 or is bent into an arch depends on the stiffness of the main body 132.

[0047] In some embodiments, referring to Figures 4 to 11 , and Figures 13 to 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 arranged around the first direction, in which the frame 140 is arranged between the edge portion 131 and the fixing portion 121, and the edge portion 131 is connected to the fixing portion 121 through the frame 140. In the first direction, the first transmission component 151 is arranged between the end 122b of the first driving arm portion 122 and the third end 132a of the main body portion 132, and the third end 132a of the main body portion 132 is connected to the end 122b of the first driving arm portion 122 through the first transmission component 151. In the first direction, the second transmission component 152 is arranged between the end 123b of the second driving arm portion 123 and the fourth end 132b of the main body portion 132, and the fourth end 132b of the main body portion 132 is connected to the end 123b of the second driving arm portion 123 through the second transmission component 152.

[0048] In the present embodiment, in the first direction, 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, so that the distance between the diaphragm 130 and the driving mechanism 120 in the first direction can be increased, and the 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 in the first direction relative to the edge portion 131 with the first driving arm portion 122 and the second driving arm portion 123.

[0050] As an embodiment, referring to the embodiment shown in Figures 4 to 9 , the embodiment shown in Figure 15 , and the embodiment shown in Figure 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 embodiment shown in Figures 10 to 12 , the connecting portion 133 comprises a plurality of spring arms 1331, and all the spring arms 1331 are arranged in 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 Figures 10 to 12The main body 132 and the edge portion 131 are square structures with mutually imitated outer contours, the diagonal lines 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 located on the same edge portion are symmetrically arranged. Each spring arm 1331 comprises 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 line of the diaphragm 130, and the first connecting segment 1332 is connected to the main body 132 and arranged close to the diagonal line, the fifth connecting segment 1336 is connected to the edge portion 131 and arranged close to the diagonal line, 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, please refer to the embodiment shown in Figures 13 to 14 The connecting portion 133 comprises a concave portion and a convex portion 1339, wherein the concave portion is at least two, each concave portion surrounds the first direction respectively, and all the concave portions are coaxially arranged, the convex portion 1339 is used for connecting the adjacent two concave portions into one, and the concave portion is recessed relative to the main body 132 and towards the base 110.

[0054] As an example, please refer to Figure 14 The connecting portion 133 can comprise 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 repeated here.

[0056] In some embodiments, please refer to Figure 15 The electro-acoustic conversion structure 100 further comprises a stiffness adjusting plate member 160. The stiffness adjusting plate member 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 member 160 is greater than the stiffness of the main body 132, so as to effectively improve the stiffness of the main body 132, and the diaphragm 130 can vibrate in a predetermined vibration mode. It can be understood that the specific stiffness of the stiffness adjusting plate member 160 can be set according to actual conditions, and will not be repeated here.

[0057] In some embodiments, please refer to Figure 5 andFigure 18 The driving mechanism 120 comprises a plurality of first driving arm portions 122 and a plurality of second driving arm portions 123, and the number of the first driving arm portions 122 is equal to the number of the second driving arm portions 123, the length of the first driving arm portions 122 in the second direction is equal to the length of the second driving arm portions 123 in the second direction, and the first driving arm portions 122 and the second driving arm portions 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 arm portions 122 are respectively connected to the third end 132a of the main body portion 132, and the ends 123b of the second driving arm portions 123 are respectively connected to the fourth end 132b of the main body portion 132.

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

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

[0060] In this embodiment, by arranging 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 arm portions 122 and the ends 123b of the second driving arm portions 123 can be avoided, and the problems such as breakage of the first driving arm portions 122 and the second driving arm portions 123 caused by excessive deformation of the first driving arm portions 122 and the second driving arm portions 123 can be effectively avoided.

[0061] For example, referring to Figure 18 The spring portion 124 can comprise two spring structures 1241 symmetrically arranged about the central axis of the corresponding driving arm portion. The spring structure 1241 comprises 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 portion, and the third elastic segment 1244 is connected to the fixed portion 121.

[0062] In some embodiments, referring to Figure 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 Figure 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 Figure 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 in 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 a 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 a first driving arm part 122 and a second driving arm part 123.

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

Claims

1. An electro-acoustic transduction structure, characterized by, The electro-acoustic transducing 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, two ends of the main body part in the second direction being fixed to the ends of the first driving arm part and the second driving arm part respectively.

2. The electro-acoustic transduction structure of claim 1, wherein, The connecting part is a folded ring structure with a middle part protruding towards a direction away from the base.

3. The electro-acoustic transduction structure of claim 1, wherein, The connecting part comprises a plurality of spring arms arranged at intervals in the first direction, one end of each spring arm being connected to the edge part, and the other end of each spring arm being connected to the main body part.

4. The electro-acoustic transduction structure of claim 1, wherein, The connecting part comprises at least two concave parts surrounding the first direction and arranged coaxially, and a convex part connecting the adjacent two concave parts into one, the concave parts being recessed towards the base relative to the main body part.

5. The electro-acoustic transduction structure of claim 1, wherein, The electro-acoustic transducing structure further comprises a rigidity adjusting plate covering one side of the main body part near the opening, for improving the rigidity of the main body part.

6. The electro-acoustic transduction structure of claim 1, wherein, The driving mechanism comprises a plurality of the first driving arm parts and a plurality of the second driving arm parts, the number of the first driving arm parts being the same as the number of the second driving arm parts, and the first driving arm parts and the second driving arm parts being alternately arranged at intervals in a third direction perpendicular to the first direction and the second direction.

7. The electro-acoustic transduction structure of claim 1, wherein, The driving mechanism further comprises a first spring part and a second spring part. The end of the first driving arm part is connected to the second end of the fixed part through the first spring part. The end of the second driving arm part is connected to the first end of the fixed part through the second spring part.

8. The electro-acoustic transduction structure of claim 1, wherein, The driving mechanism comprises a support layer, a first electrode layer, a piezoelectric layer and a second electrode layer arranged in sequence in a direction away from the base in the first direction, the support layer being connected to the base.

9. The electro-acoustic transduction structure of claim 8, wherein, The driving mechanism further comprises a passivation layer arranged on the side of the second electrode layer away from the piezoelectric layer.

10. The electro-acoustic transduction structure of claim 1, wherein, The electro-acoustic transducing structure further comprises a frame surrounding the first direction, a first transmission part and a second transmission part, the frame being used to connect the edge part and the fixed part, the first transmission part being used to connect the end of the first driving arm part and the main body part, and the second transmission part being used to connect the end of the second driving arm part and the main body part.

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