Electro-acoustic transducer, array loudspeaker, wearable device, loudspeaker, ultrasonic sound wave transmitter, and method for manufacturing electro-acoustic transducer

Abstract

To inhibit a sound wave generated on a surface of a diaphragm facing a drive unit from turning around to a surface on the opposite side of the diaphragm and improve a sound pressure level per unit area of the diaphragm.SOLUTION: An electro-acoustic transducer comprises: a diaphragm; a diaphragm support unit that connects with a part of the diaphragm in a vibration direction of the diaphragm; a drive unit having a part connecting with the diaphragm support unit to vibrate the diaphragm; a drive unit support unit that connects with the drive unit from a direction opposite to the diaphragm to support a part of the drive unit; a pedestal that connects with the drive unit support unit and has an area greater than that of the diaphragm; and an outer frame unit that connects with the pedestal from the same direction as the drive unit support unit. The outer frame unit is disposed so as to have gaps with an outer periphery of the diaphragm and an outer periphery of the drive unit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electroacoustic transducer, an array speaker, a wearable device, a speaker, an ultrasonic transmitter, and a method for manufacturing an electroacoustic transducer. [Background technology]

[0002] In recent years, development of acoustic devices such as earphones has been progressing for applications such as listening to music and videos, and video conferencing. The speaker drivers of these acoustic devices, which are electroacoustic transducers, are realized using, for example, MEMS (Micro Electro Mechanical Systems) technology. In particular, piezoelectric-driven MEMS speaker drivers using piezoelectric films have become popular in recent years due to their ease of miniaturization.

[0003] Therefore, Patent Document 1 discloses the structure of a piezoelectrically driven microspeaker having a piston diaphragm, with the aim of providing a piezoelectrically driven microspeaker with improved acoustic output. Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention aims to prevent sound waves generated on the surface of the diaphragm facing the drive unit from leaking onto the opposite surface of the diaphragm, and to improve the sound pressure level per unit area of ​​the diaphragm. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems and achieve the object, the present invention provides a vibration device comprising a vibration plate, a vibration plate support part that connects to a part of the vibration plate in the vibration direction of the vibration plate, a drive part that is partially connected to the vibration plate support part and vibrates the vibration plate, a drive part support part that connects to the drive part from the opposite direction to the vibration plate and supports a part of the drive part, a base that is connected to the drive part support part and has an area larger than the vibration plate, and an outer frame part that connects to the base from the same direction as the drive part support part, and is arranged with a gap between the outer periphery of the vibration plate and the outer periphery of the drive part. [Effects of the Invention]

[0006] According to the present invention, it is possible to suppress sound waves generated on the surface of the diaphragm facing the drive unit from flowing around to the opposite surface of the diaphragm, and to improve the sound pressure level per unit area of ​​the diaphragm. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a cross-sectional view of an electro-acoustic transducer according to a first embodiment. [Figure 2] FIG. 2 is a plan view of the electro-acoustic transducer with the vibrating portion omitted. [Figure 3] FIG. 3 is a diagram illustrating an example of a manufacturing process for an electro-acoustic transducer. [Figure 4] FIG. 4 is a diagram showing an example of a beam. [Figure 5] FIG. 5 is a diagram showing a simulation of the relationship between the gap and the sound pressure level. [Figure 6] FIG. 6 is a cross-sectional view showing a first modification of the electroacoustic transducer. [Figure 7] FIG. 7 is a cross-sectional view of an electro-acoustic transducer according to the second embodiment. [Figure 8] FIG. 8 is a plan view showing a vibrating portion and an outer frame portion of an electroacoustic transducer according to a third embodiment. [Figure 9] FIG. 9 is a perspective view showing a cross section of the electroacoustic transducer. [Figure 10]FIG. 10 is a plan view showing a vibrating portion and an outer frame portion of an electroacoustic transducer according to a fourth embodiment. [Figure 11] FIG. 11 is a perspective view showing a cross section of an electroacoustic transducer. [Figure 12] FIG. 12 is a cross-sectional view of an electro-acoustic transducer according to the fifth embodiment. [Figure 13] FIG. 13 is a plan view showing the configuration of an electroacoustic transducer according to the sixth embodiment. [Figure 14] FIG. 14 is a perspective view showing the configuration of an electroacoustic transducer. [Figure 15] FIG. 15 is a plan view showing the configuration of an electroacoustic transducer according to the seventh embodiment. [Figure 16] FIG. 16 is a plan view showing a vibrating portion and an outer frame portion of an electroacoustic transducer according to the eighth embodiment. [Figure 17] FIG. 17 is a schematic diagram illustrating an example of the configuration of a glasses-type wearable device according to the ninth embodiment. [Figure 18] FIG. 18 is a schematic diagram showing an example of the configuration of a watch-type wearable device according to the tenth embodiment. [Figure 19] FIG. 19 is a schematic diagram showing an example of the configuration of an earphone-type speaker according to the eleventh embodiment. [Figure 20] FIG. 20 is a schematic diagram showing an example of the configuration of an ultrasonic oscillator according to the twelfth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] In the structure of the piezoelectric microspeaker disclosed in Figures 1 and 3 of Patent Document 1, both ends of the piezoelectric driver are fixed to the substrate. That is, in Figures 1 and 3 of Patent Document 1, the piezoelectric driver is connected to the substrate with a doubly supported beam structure. When the piezoelectric driver is connected to the substrate with a doubly supported beam, the vibration range of the diaphragm is narrowed, restricting the movement of the diaphragm and narrowing the vibration range of the piston diaphragm. This poses a problem in that a sufficient sound pressure level cannot be obtained.

[0009] Furthermore, in the structure of the piezoelectric microspeaker disclosed in Figure 5 of Patent Document 1, one end of the piezoelectric driver is fixed to the substrate. That is, in Figure 5 of Patent Document 1, the piezoelectric driver is connected to the substrate in a cantilever structure. When the piezoelectric driver is connected to the substrate in a cantilever structure, the piston diaphragm vibrates with a rotational component centered on the fixed end, which can cause a problem of the piston diaphragm colliding with the substrate.

[0010] One way to address this issue is to widen the gap between the piston diaphragm and the substrate. Normally, the back surface of the piston diaphragm's piezoelectric actuator generates sound waves that are in the opposite phase to the sound waves generated from the surface of the piston diaphragm's piezoelectric actuator. However, if the gap between the piston diaphragm and the substrate is widened, these sound waves with the opposite phase cancel out the sound waves generated from the surface of the piston diaphragm's piezoelectric actuator. In other words, sound waves that are in the opposite phase to the sound waves generated by the intended surface of the piston diaphragm propagate through the gap, and the vibrations of the two cancel each other out.

[0011] Hereinafter, embodiments of an electroacoustic transducer, an array speaker, a wearable device, a speaker, an ultrasonic transmitter, and a method of manufacturing an electroacoustic transducer will be described in detail with reference to the accompanying drawings. In each drawing, the same components are designated by the same reference numerals, and duplicated explanations will be omitted as appropriate.

[0012] Furthermore, the embodiments described below are examples of electroacoustic transducers, array speakers, wearable devices, speakers, ultrasonic transmitters, and methods for manufacturing electroacoustic transducers to embody the technical concepts of the present invention, and the present invention is not limited to the embodiments described below.

[0013] Unless otherwise specified, the shapes of the components, their relative positions, parameter values, etc. described below are intended to be illustrative and not to limit the scope of the present invention. Furthermore, the sizes and positional relationships of the components shown in the drawings may be exaggerated for clarity of explanation.

[0014] (First embodiment) 1 is a cross-sectional view of an electroacoustic transducer 10 according to a first embodiment, and FIG. 2 is a plan view of the electroacoustic transducer 10 with the diaphragm 1a thereof omitted. The arrows shown in FIG. 1 and FIG. 2 indicate the X, Y, and Z directions. When no symbol is attached to the X, Y, or Z direction, it is assumed that both the positive and negative directions are included.

[0015] 1 includes a diaphragm 1a that generates sound waves through vibration, a diaphragm support 1b that supports the diaphragm 1a, an outer frame 3, a drive unit 5 that vibrates the diaphragm 1a, a drive unit support 6 that supports the drive unit 5, and a base 7. The diaphragm support 1b is provided in the vibration direction of the diaphragm 1a (Z direction in FIG. 1). In FIG. 1, two diaphragm support units 1b are provided.

[0016] The drive unit 5 includes a drive plate 4 that supports the diaphragm 1a, and a drive source 2 that is stacked on the drive plate 4. A drive unit support 6 supports the drive unit 5 at one end and is connected to a base 7 at the other end.

[0017] The base 7 supports the drive unit support portion 6. The base 7 is connected to the outer frame portion 3 from the same direction as the drive unit support portion 6.

[0018] The outer frame portion 3 includes a first outer frame portion 31 that forms an outer frame surrounding the outer periphery of the diaphragm 1a, and a second outer frame portion 32 that forms an outer frame surrounding the outer periphery of the drive portion 5.

[0019] In the electroacoustic transducer 10, an electric signal input to the drive source 2 causes a drive plate 4, which is made up of stacked drive sources 2 with a drive unit support portion 6 as a fixed end, to vibrate in the Z direction (the direction in which the diaphragm 1a and the drive unit 5 face each other). The electroacoustic transducer 10 is a device that generates vibrations such as sound when the diaphragm 1a vibrates in the Z direction in response to the vibration. Hereinafter, each of the main parts of the electroacoustic transducer 10 will be described in detail.

[0020] The driver support 6 is a support member with its longitudinal direction in the Y direction. The driver support 6 is located at the position indicated by the dashed line in FIG. 2, on the opposite side of the driver plate 4 from the diaphragm 1a. The driver support 6 shown in FIG. 2 is disposed so as to pass through the midpoint of the X-direction side of the driver 5 and extend in the extension direction (Y direction) of the diaphragm support 1b. This makes the distance from the driver support 6 to the driver 5 in the X direction constant, and the connection point between the driver 5 and the diaphragm support 1b vibrates with the same displacement, allowing the diaphragm 1a to vibrate parallel to the Z direction.

[0021] The drive unit support portion 6 may be larger than the range indicated by the dashed line in Fig. 2. For example, part of the area where the drive unit support portion 6 is arranged may overlap with the drive source 2. Furthermore, for example, the end portion of the drive unit support portion 6 in the Y-axis direction may protrude from the drive plate 4.

[0022] The drive source 2 may be provided on either the top or bottom surface of the drive plate 4 in the Z direction. The drive source 2 may also be provided on both surfaces of the drive plate 4. The drive unit support portion 6 may be arranged so as to connect the drive plate 4 and the base 7.

[0023] The drive unit support 6 is composed of, for example, a single layer or multiple layers of inorganic or organic material, and is preferably formed of single crystal silicon of an SOI substrate. When the drive unit support 6 is composed of multiple layers, an interlayer film composed of silicon oxide or the like may be provided between the layers constituting the drive unit support 6 or between the layers constituting the drive unit support 6 and the drive plate 4 stacked in the +Z direction of the drive unit support 6.

[0024] The drive plate 4 is stacked in the +Z direction of the drive unit support portion 6 and extends in the +X or −X direction around the drive unit support portion 6. The drive plate 4 is formed, for example, from an oxide material, an inorganic material, or an organic material, and is preferably formed from a silicon active layer. The region of the drive plate 4 extending in the X direction from the drive unit support portion 6 is supported by the drive unit support portion 6 in a state that is elastically deformable in the Z direction as a so-called cantilever structure with the region stacked with the drive unit support portion 6 as the fixed end. A diaphragm support portion 1b and multiple drive sources 2 are provided on the surface of the drive plate 4 opposite the surface stacked with the drive unit support portion 6.

[0025] Diaphragm support part 1b joins drive unit 5 and diaphragm 1a so that drive plate 4 and diaphragm 1a face each other in the Z direction. Diaphragm support part 1b has a longitudinal direction that is the same as the longitudinal direction of drive unit support part 6, and is formed along the edge located at the end of drive plate 4 in the X direction (extension direction of drive plate 4). Diaphragm support part 1b shown in FIGS. 1 and 2 is provided line-symmetrically with respect to a line parallel to the Y axis that passes through the center of diaphragm 1a within the plane of diaphragm 1a that is connected to diaphragm support part 1b. By providing diaphragm support part 1b line-symmetrically with respect to a line that passes through the center of gravity of diaphragm 1a within the plane of diaphragm 1a that is connected to diaphragm support part 1b, diaphragm 1a can be driven in translation.

[0026] 1 and 2 show a state in which the diaphragm support portion 1b is stacked on the drive source 2, but it may also be stacked on the drive plate 4. Furthermore, the diaphragm support portion 1b does not necessarily have to be aligned along the edge located at the end of the drive plate 4 in the X direction. For example, the diaphragm support portion 1b may be provided inside the edge of the drive plate 4 in the X direction (towards the center of the drive plate 4).

[0027] The distance between the connection point of diaphragm support portion 1b and drive portion 5 and the center of gravity of drive portion 5 is longer than the distance between the connection point of drive portion support portion 6 and drive portion 5 and the center of gravity of drive portion 5. That is, in the top view of FIG. 2, drive portion support portion 6 is located closer to the center in the plane of drive portion 5 than diaphragm support portion 1b. This makes it possible to increase the amount of displacement of drive portion 5, improving the sound pressure level. That is, in the top view of FIG. 2, drive portion support portion 6 is located closer to the center in the plane of drive portion 5 than diaphragm support portion 1b.

[0028] Furthermore, it is preferable that the connection point between the driver support portion 6 and the driver 5 is at a position different from the connection point between the diaphragm support portion 1b and the driver 5 on the surface opposite to the surface where the driver 5 and the driver support portion 1b are connected. In other words, it is preferable that the diaphragm support portion 1b and the driver 5 do not overlap when the surface of the driver 5 is viewed from the direction perpendicular to the surface (Z direction). Furthermore, it is more preferable that the position where the diaphragm support portion 1b is connected to the driver 5 is further outside the position where the driver support portion 6 is connected to the driver 5. This ensures a sufficient amount of vibration displacement of the diaphragm 1a.

[0029] The driving source 2 is a piezoelectric actuator (piezoelectric film) that is driven by applying a voltage. The driving source 2 controls a signal for generating vibrations such as sound, and is electrically connected to an external control device that controls the signal toward the electro-acoustic transducer 10. The driving source 2 has a lower electrode, a piezoelectric portion, and an upper electrode laminated in this order on the driving plate 4. The lower electrode and the upper electrode are made of, for example, gold (Au) or platinum (Pt). The piezoelectric portion is made of, for example, a piezoelectric material such as PZT (lead zirconate titanate). However, the material for the piezoelectric portion is not limited to this. The driving source 2 may also have a structure in which multiple piezoelectric portions are laminated and an intermediate electrode is included.

[0030] When a voltage is applied to the drive source 2, strain occurs in the piezoelectric portion of the drive source 2 in the in-plane direction (X and Y directions), causing the drive plate 4 to deform in the Z direction. When the voltage applied to the drive source 2 is changed over time, the diaphragm 1a vibrates via the diaphragm support portion 1b, generating pressure waves in the surrounding air, which are perceived by humans as sound. The input voltage waveform is a voltage-converted version of the waveform of the sound to be reproduced, and sound is reproduced by inputting this voltage waveform to the drive source 2. The drive source 2 may be provided on either the upper or lower side of the drive plate 4 along the Z axis, or on both sides.

[0031] The drive sources 2 are arranged in multiple line symmetry or point symmetry across the area where the drive plate 4 and the drive unit support unit 6 are stacked. By arranging the drive sources 2 with good symmetry, deformation of the diaphragm 1a during vibration can be reduced.

[0032] The diaphragm 1a is a plate-like member formed in a rectangular shape. Two sides of the diaphragm 1a that face each other in the X direction are joined to the driving unit 5 in the Z direction via diaphragm support members 1b. In other words, the diaphragm 1a is positioned opposite the driving unit 5 in the Z direction. The area of ​​the diaphragm 1a as viewed from the Z direction (in a plan view) is preferably equal to or greater than the total area of ​​the driving plate 4 in a plan view. The shape of the diaphragm 1a is not limited to a rectangle and may be any shape.

[0033] The outer frame 3 is connected to the base 7 and is provided on the outer periphery of the diaphragm 1a and the drive unit 5. The outer frame 3 is not fixed to the outer periphery of the drive unit 5, but is arranged with a predetermined gap from the outer periphery of the drive unit 5, thereby increasing the range of motion of the drive unit 5 and improving the sound pressure level per unit area of ​​the diaphragm 1a. The outer frame 3 is arranged with a predetermined gap from the outer periphery of the diaphragm 1a, thereby suppressing sound waves generated on the surface of the diaphragm 1a facing the drive unit 5 from leaking to the opposite surface of the diaphragm 1a and improving the sound pressure level per unit area of ​​the diaphragm 1a. In other words, it is possible to suppress sound waves of opposite phase generated on the back surface (-Z direction surface) of the diaphragm 1a from leaking to the front surface (-Z direction surface). The sound waves generated on the back surface of the diaphragm 1a are in opposite phase to the sound waves generated on the front surface of the diaphragm 1a.

[0034] The diaphragm 1a and diaphragm support 1b are formed by, for example, a MEMS (Micro Electro Mechanical Systems) process. Manufacturing by the MEMS process has higher productivity and is more cost-effective than conventional methods, making it possible to provide high-quality electro-acoustic transducers 10 to a wider market.

[0035] When the diaphragm 1a is formed by, for example, an MEMS process, it is formed from a silicon active layer or the like. However, the process and material for forming the diaphragm 1a are not limited to this. Materials for forming the diaphragm 1a can be selected from, for example, metals such as magnesium, titanium, and aluminum, carbon nanofiber, cellulose nanofiber, paper, and CFRP.

[0036] The first outer frame portion 31 that forms the outer frame of the diaphragm 1a includes a first layer 31a and a second layer 31b. The second outer frame portion 32 that forms the outer frame of the driver 5 includes a third layer 32a and a fourth layer 32b.

[0037] The diaphragm 1a, the drive plate 4, the first layer 31a, and the third layer 32a contain the same material, such as an oxide material, an inorganic material, or an organic material, and preferably a silicon active layer.

[0038] The diaphragm support 1b, the drive unit support 6, the second layer 31b, and the fourth layer 32b contain the same material. For example, the materials constituting the diaphragm support 1b, the drive unit support 6, the second layer 31b, and the fourth layer 32b may be a single layer or multiple layers of inorganic or organic materials, preferably formed of single-crystal silicon of an SOI substrate. When the second layer 31b and the fourth layer 32b are multiple layers, an interlayer film made of silicon oxide or the like may be provided between the layers constituting the second layer 31b and the fourth layer 32b or between the second layer 31b and the fourth layer 32b and the drive plate 4 stacked in the +Z direction.

[0039] Next, a method for manufacturing the electroacoustic transducer 10 using the MEMS process will be described.

[0040] Fig. 3 is a diagram illustrating an example of a manufacturing process for the electro-acoustic transducer 10. The left side of Fig. 3 shows a cross-sectional view of the electro-acoustic transducer 10, and the right side of Fig. 3 shows a plan view of the electro-acoustic transducer 10. The manufacturing process for the electro-acoustic transducer 10 shown in Fig. 3 is realized by MEMS technology.

[0041] First, a support layer (single crystal silicon of an SOI substrate) and a silicon active layer are stacked to form an SOI wafer. Next, a pattern is formed on the SOI wafer. This pattern formation can be performed by photolithography and etching, or by lift-off using a resist pattern. After that, etching is performed from the front and back surfaces to form structures 20 and 30 shown in FIG. 3 (first and second steps).

[0042] As shown in FIG. 3(a), the structure 20 is a first member including a diaphragm 1a, a diaphragm support portion 1b, a first outer frame portion 31, and a beam 40. The structure 30 is a second member including a drive portion 5, a drive portion support portion 6, and a second outer frame portion 32. First, as shown in FIG. 3(a), the structure 20, the structure 30, and the base 7 are separately prepared.

[0043] As shown in FIG. 3(a), a portion of the diaphragm 1a is connected to the outer frame portion 3 (first outer frame portion 31) via a beam 40. The beam 40 has a structure that causes it to break when driven, for example, by applying a voltage to the driving source 2 of the driving unit 5. The connection width of the beam 40 with the diaphragm 1a is 1 / 3 or less of the length of one side of the diaphragm 1a on which the beam 40 is provided. The diaphragm 1a may be circular. When the diaphragm 1a is circular, the beam 40 is more likely to break if it has a width of 1 / 3 or less of the diameter of the circle of the diaphragm 1a.

[0044] Next, as shown in FIG. 3(b), die bonding is performed to fix the structure 20 (the vibration plate 1a and vibration plate support portion 1b connected to the outer frame portion 3 (first outer frame portion 31)) to the structure 30 (the drive portion 5 and second outer frame portion 32) with an adhesive such as silver paste. Then, die bonding is performed to fix the structure 30 with the structure 20 fixed to it to the base 7 with an adhesive such as silver paste (third process). Note that in this embodiment, the process of bonding the structure 20 and the structure 30 together and then fixing them to the base 7 has been described, but the present invention is not limited to this, and a process of fixing the structure 30 to the base 7 and then bonding the structure 20 may also be performed.

[0045] 3(c), the beams 40 are destroyed or removed by a predetermined method, for example, by applying a voltage to the driving source 2 of the driving unit 5 to destroy or remove the beams 40 (fourth step).

[0046] FIG. 4 illustrates an example of a beam 40. As shown in FIGS. 4(a) and 4(b), the beam 40 has a localized constriction 40a that locally reduces the area of ​​the beam 40 at the middle or a specific position of the beam 40. The example of the constriction 40a shown in FIG. 4(a) is shaped so that the connection position with the diaphragm 1a becomes a portion where stress concentration occurs. The example of the constriction 40a shown in FIG. 4(b) is shaped so that a notch is provided on at least one side of the beam 40 in the longitudinal direction, and the notch position becomes a portion where stress concentration occurs. In other words, in a beam 40 having such a structure, the constriction 40a that causes the above-mentioned stress concentration becomes the starting point of fracture, making it possible to prevent unintentional fracture in other portions.

[0047] As described above, the adoption of a destructible beam 40 having a constricted portion 40a ensures the proper positional relationship between the vibration plate 1a and the outer frame portion 3, thereby improving the accuracy and quality of the assembly of the vibration plate 1a and the outer frame portion 3 in the MEMS process.

[0048] The structure of this embodiment is particularly effective in the process of bonding the diaphragm 1a to the drive unit 5 after the diaphragm 1a and outer frame 3 are integrally formed. By applying a voltage to the drive source 2 of the drive unit 5, the diaphragm 1a is vibrated, and the beams 40 are broken at their constricted portions 40a. This breaking occurs with the diaphragm 1a and outer frame 3 fixed in the appropriate positions, improving the precision and reproducibility of the product.

[0049] Conventionally, when the diaphragm 1a is vibrated as is, sound waves generated on the back side of the diaphragm 1a, which are out of phase with the sound waves generated on the front side, find their way to the front side of the diaphragm 1a, reducing the sound pressure level. To solve this problem, it is necessary to place the diaphragm 1a not in a free sound field, but to place the outer frame 3. To prevent the out-of-phase sound waves generated on the back side of the diaphragm 1a from finding their way to the front side of the diaphragm 1a, it is preferable to set the gap to 5 μm or less.

[0050] However, in this case, if the structure of the drive source 2 of the drive unit 5 that operates the diaphragm 1a is a simple cantilever beam structure, the diaphragm 1a will have many components other than translational motion because it has a motion component that rotates from the fixed end. Therefore, if the displacement of the drive unit 5 is increased to obtain a high sound pressure level, the diaphragm 1a may come into contact with the outer frame 3. Also, if a doubly supported beam structure that does not have a rotational motion component is used, it is possible to prevent contact with the outer frame 3, but because both ends are fixed, the momentum of the drive unit 5 is small and it is not possible to increase the sound pressure level.

[0051] Therefore, in this embodiment, the outer frame 3 is disposed with a predetermined gap from the outer periphery of the diaphragm 1a. Specifically, the gap from the outer periphery of the diaphragm 1a is 5 μm or less. This prevents sound waves generated on the back side of the diaphragm 1a from leaking around to the front side of the diaphragm 1a.

[0052] 1, the driving source 2 of the driving unit 5 has a simple cantilever structure with the driving unit support unit 6 as a fixed end, and is positioned symmetrically about the center of the diaphragm 1a. This structure allows the driving unit 5 to perform translational motion without a rotational component while obtaining a large amount of displacement.

[0053] This structure prevents the intrusion of antiphase waves from the rear surface of the diaphragm 1a, and also makes it possible to ensure a sufficiently large displacement of the vibrating portion.

[0054] According to this embodiment, the drive unit 5 and the drive unit support unit 6 are provided in the same direction (-Z direction) relative to the surface of the diaphragm 1a. The drive sources 2 of the multiple drive units 5 are configured to extend in the X direction with the drive unit support unit 6 as the center. That is, the drive sources 2 of the drive units 5 are configured to drive the diaphragm 1a as a so-called cantilever structure with the extension region of the drive unit support unit 6 as a fixed end. This configuration can obtain a larger displacement than a configuration in which both ends of the drive unit 5 are connected to the drive unit support unit 6 and both ends of the drive unit 5 are fixed ends. That is, the configuration of this embodiment can increase the amplitude of vibration of the diaphragm 1a.

[0055] In this embodiment, these configurations prevent sound waves generated on the surface of the diaphragm 1a facing the drive unit 5 from leaking around to the opposite surface of the diaphragm 1a, and also improve the sound pressure level per unit area of ​​the diaphragm 1a.

[0056] Furthermore, the driving unit 5 is configured to drive both ends of the diaphragm 1a via the diaphragm support unit 1b. This reduces distortion of the diaphragm 1a due to the driving force compared to when the center of the diaphragm 1a is driven, allowing the diaphragm 1a to vibrate parallel to the Z direction (vibration direction). This makes it possible to further reduce distortion (THD: Total Harmonic Distortion) that occurs when the electro-acoustic transducer 10 is driven.

[0057] It is extremely difficult to position the outer frame 3 at a position where the gap between the diaphragm 1a and the outer frame 3 is 5 μm or less using ordinary machining, resulting in a significant drop in productivity. To solve this problem, in this embodiment, a gap of 5 μm or less is designed between the diaphragm 1a and the outer frame 3, and they are formed all at once using an MEMS process. With this type of MEMS process, it is easy to position the outer frame 3 at a position where the gap between the diaphragm 1a and the outer frame 3 is 5 μm or less.

[0058] As described above, in this embodiment, the diaphragm 1a and a portion of the outer frame 3 are connected by very thin, easily breakable beams 40. These beams 40 bond the diaphragm 1a and a portion of the outer frame 3 to the drive unit 5, maintaining a gap of 5 μm or less. Then, after the diaphragm 1a connected to the outer frame 3 is fixed to the drive unit 5 with an adhesive, a voltage is applied to the drive source 2 of the drive unit 5 to operate the diaphragm 1a and break the beams 40. This method makes it possible to reduce the gap between the outer frame 3 and the diaphragm 1a to 5 μm or less using a MEMS process, allowing the electro-acoustic transducer of this embodiment to be manufactured with high productivity.

[0059] FIG. 5 is a diagram showing a simulation of the relationship between gap G and sound pressure level. In FIG. 5, a simulation of sound pressure level was performed when gap G was set to 5 μm and 10 μm in the electro-acoustic transducer of FIGS. 1 and 2. In FIG. 5, the vertical axis represents the non-dimensional sound pressure level, and the horizontal axis represents the frequency. As shown in FIG. 5, in the range from 100 Hz to 1000 Hz, a gap G of 5 μm resulted in a higher sound pressure level than when gap G was set to 10 μm.

[0060] (Variation 1) In this embodiment, the first outer frame portion 31 and the second outer frame portion 32 that constitute the outer frame portion 3 are formed separately, but this is not limited to this. FIG. 6 is a cross-sectional view showing Modification 1 of the electro-acoustic transducer. As shown in FIG. 6, the first outer frame portion 31 and the second outer frame portion 32 that constitute the outer frame portion 3 may be formed integrally. This prevents sound waves of opposite phase that are generated on the back side of the diaphragm 1a from reaching the front side of the diaphragm 1a. Furthermore, the drive unit support portion 6 and the base 7 may be formed integrally.

[0061] (Second embodiment) Next, a second embodiment will be described.

[0062] The second embodiment differs from the first embodiment in that the base connected to the outside of the drive unit is designed to be slightly higher. In the following explanation of the second embodiment, explanation of the same parts as in the first embodiment will be omitted, and only the parts that differ from the first embodiment will be explained.

[0063] 7 is a cross-sectional view of an electroacoustic transducer 10 according to the second embodiment. As shown in Fig. 7, in this embodiment, a difference in height of the pedestal 7 provided in the driving unit 5 is utilized to appropriately apply stress to the beam 40, which is prone to breakage, thereby realizing a structure that controls breakage of the beam 40.

[0064] As shown in FIG. 7 , in this embodiment, too, the driver 5 is connected to the base 7 via the driver support 6. However, in this embodiment, the base 7 is designed so that the part connected to the outer frame 3 outside the driver 5 and the part supporting the driver 5 have different heights (thickness in the vibration direction of the diaphragm 1a). Specifically, the base 7 directly connected to the center of the driver 5 via the driver support 6 is designed to be relatively low. On the other hand, the base 7 connected to the outer frame 3 outside the driver 5 is designed to be slightly higher by the height of the base 7a. This difference in height allows an appropriate stress to be applied to the fragile beams 40 when the driver 5 and the diaphragm 1a are bonded to the base 7.

[0065] As described above, the thickness of the base 7 at the connection point with the second outer frame portion 32 in the vibration direction of the diaphragm 1a is thicker than the thickness of the connection point with the drive unit support portion 6. That is, in this embodiment, the distance from the surface of the outer frame portion 3 opposite the surface connected to the base 7 to the base 7 is longer than the distance from the diaphragm 1a to the base 7.

[0066] With this structure, after the driver 5 and diaphragm 1a are attached to the base 7, a pre-calculated stress is applied to the fragile beam 40, making it more susceptible to breakage. This stress is generated by mechanical strain caused by the height difference. This method makes it possible to break the beam 40 efficiently and accurately.

[0067] As described above, according to this embodiment, the connection structure between the driver 5 and the diaphragm 1a using the base 7 with a difference in height allows for more precise and effective control of the destruction of the beam 40 in the MEMS device, thereby improving the reliability and performance of the MEMS device and enabling a wider range of applications.

[0068] Furthermore, as shown in FIG. 7, in this embodiment, the base 7 connected to the outer frame portion 3 is designed to be slightly higher by the amount of the base 7a, so that even when the vibration plate 1a reaches its highest point, the presence of the wall surface of the first outer frame portion 31 prevents a gap larger than 5 μm from occurring.

[0069] (Third embodiment) Next, a third embodiment will be described.

[0070] The third embodiment differs from the first embodiment in that a breakable beam 40 is installed near the connection point where the diaphragm support portion 1b and the diaphragm 1a are connected. In the following description of the third embodiment, the description of the same parts as in the first embodiment will be omitted, and only the parts that differ from the first embodiment will be described.

[0071] Here, Fig. 8 is a plan view showing the diaphragm 1a and outer frame 3 of an electroacoustic transducer 10 according to the third embodiment, and Fig. 9 is a perspective view showing a cross section of the electroacoustic transducer 10. Note that Fig. 9 omits the diaphragm 1a and base 7 of the electroacoustic transducer 10. In this embodiment, a structure that facilitates destruction under specific operating conditions is realized by arranging the fragile beams 40 near the connection point between the drive unit 5 and the diaphragm 1a. Note that although the fragile beams 40 are provided on the diaphragm 1a, the diaphragm 1a is omitted in Fig. 9.

[0072] Here, in this embodiment, the vicinity of the connection point between the diaphragm support portion 1b and the diaphragm 1a refers to the vicinity of each of the plurality of diaphragm support portions 1b on the drive portion 5, as shown in FIGS.

[0073] 8 and 9, in this embodiment, the frangible beams 40 are installed near a plurality of diaphragm support parts 1b on the driving section 5. With this arrangement, mechanical stress generated between the diaphragm 1a and the plurality of diaphragm support parts 1b on the driving section 5 is directly and efficiently transmitted to the frangible beams 40. This transmitted stress can be adjusted based on design requirements and is controlled in accordance with the fracture threshold of the beams 40.

[0074] With this arrangement, the interaction between the diaphragm 1a and the multiple diaphragm support parts 1b on the drive unit 5 directly affects the fragile beam 40, making it easier for the beam 40 to break under certain conditions. For example, under certain pressure or temperature conditions, the interaction between the diaphragm support parts 1b on the drive unit 5 and the diaphragm 1a increases, resulting in an increase in stress applied to the fragile beam 40. If this stress exceeds the design fracture threshold of the beam 40, the beam 40 breaks, causing the required function to be changed or adjusted.

[0075] As described above, according to this embodiment, by arranging the easily breakable beams 40 near the connection points between the diaphragm 1a and the plurality of diaphragm support members 1b, the destruction of the beams 40 in the MEMS device can be controlled more directly and effectively. This improves the responsiveness and reliability of the MEMS device, and achieves efficient and accurate control of the destruction of the beams 40 under specific operating conditions, enabling precise control of the device behavior.

[0076] (Fourth embodiment) Next, a fourth embodiment will be described.

[0077] The fourth embodiment differs from the first embodiment in that a destruction mechanism controlled according to the volume is realized by the arrangement of the beams 40. In the following explanation of the fourth embodiment, explanation of the same parts as in the first embodiment will be omitted, and only the parts that differ from the first embodiment will be explained.

[0078] Here, Fig. 10 is a plan view showing the diaphragm 1a and outer frame portion 3 of an electroacoustic transducer 10 according to the fourth embodiment, and Fig. 11 is a perspective view showing a cross section of the electroacoustic transducer 10. Note that in Fig. 11, the diaphragm 1a of the electroacoustic transducer 10 is omitted. In this embodiment, a destruction mechanism that is controlled according to the volume is realized by the arrangement of the beams 40. Note that in Fig. 10, the distance between the first outer frame portion 31 (first layer 31a) and the beams 40, the distance between the beams 40 and the diaphragm 1a, and the distance between the beams 40 are all preferably 5 µm or less.

[0079] As shown in Figures 10 and 11, in this embodiment, at least two beams 40 are provided. The beams 40 are arranged to connect the diaphragm 1a to the first outer frame portion 31 that forms the outer frame of the diaphragm 1a. Specifically, in this embodiment, the beams 40 are arranged to connect the diagonals of the diaphragm 1a and surround the outer periphery of the diaphragm 1a. The total length of the at least two beams 40 is equal to or greater than the outer periphery of the diaphragm 1a.

[0080] By arranging at least two beams 40 as described above, when the displacement of diaphragm 1a is small, that is, when used at a low volume, beams 40 function without being broken. On the other hand, when used at a high volume, the displacement of diaphragm 1a becomes large, and only then will beams 40 be broken.

[0081] In this way, this embodiment makes it possible to control the destruction according to the volume, achieving both durability when used at low volumes and responsiveness when used at high volumes. In this embodiment, the selection of material for the beam 40 and the cross-sectional shape of the beam are also important factors, and are optimized to achieve the desired displacement characteristics and destruction characteristics.

[0082] (Fifth embodiment) Next, a fifth embodiment will be described.

[0083] The fifth embodiment differs from the first embodiment in that it has an improved structure for minimizing fluctuations in the gap caused by the up and down movement of the diaphragm 1a. In the following description of the fifth embodiment, the same parts as those in the first embodiment will be omitted, and only the differences from the first embodiment will be described.

[0084] 12 is a cross-sectional view of an electroacoustic transducer 10 according to the fifth embodiment. As shown in FIG. 12, this embodiment is characterized by an improved structure for minimizing fluctuations in the gap caused by the up and down movement of the diaphragm 1a.

[0085] As shown in FIG. 12 , in this embodiment, a third outer frame portion 33 is provided, which has a shape corresponding to the upper portion of a first outer frame portion 31 that forms the outer frame surrounding the periphery of the diaphragm 1a. The third outer frame portion 33 can be manufactured using a MEMS process. The third outer frame portion 33 is bonded to the upper portion of the first outer frame portion 31 that forms the outer frame of the diaphragm 1a, thereby ensuring that the gap between the diaphragm 1a and the outer frame portion 31 is always kept at 5 μm or less even when the diaphragm 1a vibrates up and down. Specifically, the wall surface of the third outer frame portion 33 prevents a gap greater than 5 μm from occurring, even when the diaphragm 1a reaches its highest point.

[0086] That is, in this embodiment, the distance from the surface of outer frame portion 3 opposite to the surface connected to base 7 to base 7 is longer than the distance from diaphragm 1a to base 7.

[0087] As described above, according to this embodiment, the structure described above effectively prevents sound waves from leaking between the diaphragm 1a and the outer frame 3, preventing a decrease in sound pressure level. Furthermore, the third outer frame 33 can be manufactured using a MEMS process, achieving desired performance without sacrificing productivity. This embodiment improves the performance of the MEMS speaker and realizes more efficient manufacturing.

[0088] (Sixth embodiment) Next, a sixth embodiment will be described. In the following description of the sixth embodiment, the description of the same parts as those in the first embodiment already described will be omitted, and only the parts different from the first embodiment will be described.

[0089] Here, Fig. 13 is a plan view showing the configuration of an electroacoustic transducer 11 according to the sixth embodiment, and Fig. 14 is a perspective view showing the configuration of the electroacoustic transducer 11. Note that in Figs. 13 and 14, the diaphragm 1a, outer frame 3, and base 7 are omitted because they are the same as those in the first embodiment. The electroacoustic transducer 11 shown in Figs. 13 and 14 differs in that a diaphragm support portion 1b is located between adjacent drive portions 5 in the Y direction. Furthermore, the diaphragm support portion 1b includes a spring portion 8 that is displaced in the Z direction relative to the drive portion 5.

[0090] The diaphragm support portion 1b is provided on the free end side (extension direction end side) of each pair of adjacent drive portions 5 in the Y direction, i.e., between adjacent drive portions 5. The diaphragm support portion 1b is connected to the adjacent drive portion 5 by a pair of spring portions 8.

[0091] The spring portion 8 has a shape symmetrical with respect to the joint position of the diaphragm support portion 1b with the diaphragm 1a. The spring portion 8 is formed from a part of the drive plate 4 and has a folded structure that extends from the free end of the drive portion 5 toward the fixed end. This allows the spring portion 8 to deform in the Z direction relative to the drive portion 5, with the joint position between the spring portion 8 and the drive portion 5 as the axis of rotation.

[0092] According to this embodiment, the diaphragm support portion 1b is configured to be displaceable in the vibration direction of the diaphragm 1a relative to the drive portion 5 between adjacent drive portions 5. This allows only the component of the driving force of the drive portion 5 in the vibration direction to be transmitted to the diaphragm 1a, thereby further increasing the vibration amplitude of the diaphragm 1a. This improves the sound pressure level per unit area of ​​the diaphragm 1a. Furthermore, the diaphragm 1a is less subject to distortion due to the driving force than when the spring portion 8 is not provided, allowing it to vibrate parallel to the Z direction (vibration direction). This further reduces distortion that occurs when the electro-acoustic transducer 11 is driven. Furthermore, the width of each drive portion 5 in the direction perpendicular to the extension direction is different between the end portion of the diaphragm 1a and the drive portion support portion 6 side. That is, the width of the drive portion 5 in the lateral direction is smaller at the end portion in the extension direction than at the drive portion support portion 6 side. This prevents the increase in the layout area caused by the provision of the spring portion 8.

[0093] 13 and 14, the configuration has three or more pairs of drive units 5 and two or more pairs of diaphragm support units 1b equipped with spring units 8. In this case, the ratio of the length of the drive units 5 in the X direction to the length in the Y direction can be increased. This increases the rate of deformation of the drive units 5 in the X direction compared to the deformation in the Y direction, thereby more efficiently improving the sound pressure level (also referred to as the amplitude of the generated vibration) and reducing THD. Furthermore, since the diaphragm 1a can be supported at more points, the vibration of the diaphragm 1a can be more stabilized.

[0094] (Seventh embodiment) Next, a seventh embodiment will be described. In the following description of the seventh embodiment, the description of the same parts as those in the first embodiment already described will be omitted, and only the parts different from the first embodiment will be described.

[0095] FIG. 15(a) is a plan view showing the configuration of an electroacoustic transducer 12 according to a seventh embodiment. FIG. 15(b) is a plan view of the electroacoustic transducer 12 shown in FIG. 15(a) with the diaphragm 1a omitted. The outer frame 3 in this embodiment is the same as that in the first embodiment and is therefore omitted. The electroacoustic transducer 12 shown in FIGS. 15(a) and 15(b) differs from the first embodiment in that the diaphragm 1a is hexagonal. The electroacoustic transducer 12 also differs from the first embodiment in that the drive unit 5 is arranged point-symmetrically with respect to the drive unit support unit 6.

[0096] The electroacoustic transducer 12 in this embodiment has six drive units 5 that extend radially from the drive unit support unit 6. The six drive units 5 are arranged point-symmetrically with respect to the drive unit support unit 6. By arranging the drive units 5 point-symmetrically and vibrating the diaphragm 1a, it is possible to cancel out vibration components other than those in the Z direction generated by each drive unit 5. This allows the diaphragm 1a to vibrate more stably, thereby reducing THD. Note that the number of drive units 5 shown in this embodiment is not limited to six, and may be three or more.

[0097] Furthermore, it is preferable that the width in the short side direction at the end side in the extension direction of each drive unit 5 (sometimes referred to as the edge side of the diaphragm 1a) is equal to or greater than the width of the diaphragm support unit 1b. This makes it possible to strengthen the contact surface between the drive unit 5 and the diaphragm support unit 1b, and to prevent damage due to vibrations caused by the drive of the drive unit 5. Note that the width in the short side direction of the drive unit 5 on the drive unit support unit 6 side may be equal to or less than the width of the diaphragm support unit 1b. By making the width in the short side direction of the drive unit 5 on the drive unit support unit 6 side equal to or less than the width of the diaphragm support unit 1b, it is possible to increase the number of drive units 5 that can be arranged, and to make the diaphragm 1a vibrate more stably.

[0098] 15, each of the multiple drive units 5 arranged in a point-symmetrical arrangement may have different widths in the short side direction between the end side in the extension direction and the drive unit support unit 6 side. For example, by making the width in the short side direction of the drive unit 5 larger at the end side in the extension direction than at the drive unit support unit 6 side, the area of ​​the drive source 2 can be increased, and the drive force of the drive unit 5 can be increased. This can improve the drive sensitivity of the diaphragm 1a.

[0099] It is also possible to arrange a plurality of electroacoustic transducers 12 on the same plane to configure an array-type electroacoustic transducer (array speaker). By arranging a plurality of electroacoustic transducers on the same plane, the directionality of the generated vibration can be improved. In other words, the reach of the vibration generated in the vibration direction of the diaphragm 1a can be increased. In this case, from the viewpoint of improving the directionality of the vibration, it is preferable to arrange the plurality of electroacoustic transducers 12 in a close-packed manner, such as in a triangular lattice pattern.

[0100] (Eighth embodiment) Next, an eighth embodiment will be described.

[0101] The eighth embodiment differs from the MEMS process of the first embodiment in that the beam 40 is formed using 3D printing technology. In the following description of the eighth embodiment, descriptions of the same parts as those of the first to seventh embodiments will be omitted, and only differences from the first to seventh embodiments will be described.

[0102] In this embodiment, a method for forming an easily breakable beam 40 using a 3D printing technique independent of the MEMS process is described, with the aim of improving flexibility and efficiency in the manufacturing process of MEMS devices.

[0103] Here, Fig. 16 is a plan view showing the diaphragm 1a and outer frame portion 3 of the electroacoustic transducer 10 according to the eighth embodiment. Fig. 16(a) shows the diaphragm 1a and the first layer 31a of the outer frame portion 3, and Fig. 16(b) shows the state in which beams 40 are formed on the diaphragm 1a and the first layer 31a of the outer frame portion 3 using 3D printing technology.

[0104] As shown in Figure 16, in this embodiment, the easily breakable beam 40 is formed by 3D printing technology instead of silicon or other traditional MEMS materials. The beam 40 functions to connect the diaphragm 1a and the outer frame 3 and is manufactured independently of the MEMS process. By employing 3D printing technology, the design, shape, and size of the beam 40 can be easily changed.

[0105] After the beams 40 are formed by 3D printing technology, the diaphragm 1a, which is connected to the outer frame portion 31 by the beams 40, is die-bonded to the drive portion 5 and the outer frame portion 32 with an adhesive such as silver paste.

[0106] After the driver 5 has been fixed to the diaphragm 1a, which is connected to the outer frame 3 by the beams 40, in this embodiment, the easily breakable beams 40 formed by 3D printing technology are removed and destroyed using a method such as melting or laser. This chemical removal process selectively acts on the beams 40, effectively removing only the easily breakable beams 40 without damaging other MEMS structures.

[0107] As described above, this embodiment improves the flexibility of the MEMS process, facilitating the integration of different materials and structures. Furthermore, the use of 3D printing technology makes it possible to realize complex beam structures that were difficult to achieve using conventional MEMS manufacturing methods. This is expected to improve the design and performance of MEMS devices.

[0108] As described above, according to this embodiment, the formation and removal of the easily breakable beams 40 using 3D printing technology achieves improved flexibility and efficiency in the manufacturing process of MEMS devices.

[0109] (Ninth embodiment) The above-described first to seventh embodiments can be applied not only to electro-acoustic transducers but also to acoustic devices having electro-acoustic transducers such as earphones, headphones, speakers, etc. Furthermore, the present invention can also be incorporated as an acoustic device into a wearable device that can be worn directly or indirectly on the user's body, such as a wristwatch type, eyeglasses type, HMD (Head Mounted Display) type, or torso-mounted type.

[0110] In particular, acoustic equipment incorporated into wearable devices is preferably small and low power consumption from the standpoints of extending operating time, reducing size and weight, and design. In contrast, the first to seventh embodiments can improve the sound pressure level per area where the electro-acoustic transducer is placed and per unit area of ​​the vibrating section. That is, the first to seventh embodiments can be mounted as an acoustic device that can output a larger volume with a given amount of power while keeping the size of the electro-acoustic transducer small. Therefore, an acoustic device to which the first to seventh embodiments are applied can prevent the entire wearable device from becoming larger and improve design freedom. At the same time, an acoustic device to which the first to seventh embodiments are applied can reduce power consumption when outputting volume. Application examples will be described below.

[0111] The ninth embodiment will be described with reference to Fig. 17. In the following description of the ninth embodiment, the description of the same parts as those in the first to seventh embodiments already described will be omitted, and only the parts that differ from the first to seventh embodiments will be described.

[0112] FIG. 17 is a schematic diagram showing an example of the configuration of an eyeglass-type wearable device according to a ninth embodiment. The eyeglass-type wearable device 2000 shown in FIG. 17 has a speaker 1000 and temples 2001. The speaker 1000 corresponds to the electro-acoustic transducer described above as the first to seventh embodiments. When the speaker 1000 is mounted on the eyeglass-type wearable device 2000, it is preferable to place the speaker 1000 on the inner surface of the temple 2001 (the surface facing the user when worn). In particular, when the speaker 1000 is used as a bone conduction speaker, it is preferable to place the speaker 1000 on the temple 2001 in a position that comes into contact with the surface of the user's head.

[0113] (Tenth embodiment) Next, a tenth embodiment will be described with reference to Fig. 18. In the following description of the tenth embodiment, the description of the same parts as those in the first to seventh embodiments already described will be omitted, and only the parts that differ from the first to seventh embodiments will be described.

[0114] Fig. 18 is a schematic diagram showing an example of the configuration of a watch-type wearable device according to embodiment 10. The watch-type wearable device 3000 shown in Fig. 18 has a speaker 1000, a liquid crystal screen 3001, and an outer periphery 3002 of the liquid crystal screen.

[0115] When the speaker 1000 is mounted on a wristwatch-type wearable device 3000 , it is preferable to place the speaker 1000 on the outer periphery 3002 of the liquid crystal screen 3001 .

[0116] (Eleventh embodiment) Next, an eleventh embodiment will be described with reference to Fig. 19. In the following description of the eleventh embodiment, the description of the same parts as those in the first to seventh embodiments already described will be omitted, and only the parts that differ from the first to seventh embodiments will be described.

[0117] Fig. 19 is a schematic diagram showing an example of the configuration of an earphone-type speaker according to Embodiment 11. The earphone-type speaker 4000 shown in Fig. 19 includes the speaker 1000, a fitting portion 4001 to be fitted to the user's ear, and an opening 4002.

[0118] When the speaker 1000 is mounted in the earphone 4000, it is preferable that the opening 4002 of the attachment part 4001 that is attached to the ear is arranged in the normal direction of the driving plate of the speaker 1000.

[0119] (Twelfth embodiment) Furthermore, the electroacoustic transducers according to the first to seventh embodiments can also be applied to ultrasonic transmitters that generate ultrasonic waves by vibration of the electroacoustic transducer.

[0120] Next, a twelfth embodiment will be described with reference to Fig. 20. In the following description of the twelfth embodiment, the description of the same parts as those in the first to seventh embodiments already described will be omitted, and only the parts that differ from the first to seventh embodiments will be described.

[0121] Fig. 20 is a schematic diagram showing an example of the configuration of an ultrasonic oscillator according to the twelfth embodiment. The ultrasonic oscillator 5000 shown in Fig. 20 has at least an ultrasonic vibrator 1002 and a processing unit 5001. The ultrasonic vibrator 1002 corresponds to the electro-acoustic transducer described above as the first to seventh embodiments.

[0122] The ultrasonic transmitter 5000 outputs ultrasonic waves from the ultrasonic vibrator 1002 based on an electrical signal controlled by the processing unit 5001 .

[0123] (Supplementary embodiment) So far, we have described an electro-acoustic transducer according to one embodiment of the present invention, but it is not limited to the above-mentioned embodiment, and other modifications, such as additions, changes, or deletions, can be made within the scope that can be conceived by a person skilled in the art, and any aspect is included in the scope of the present invention as long as it achieves the functions and effects of the present invention.

[0124] For example, aspects of the present invention are as follows. <1> A diaphragm and a diaphragm support portion connected to a part of the diaphragm in a vibration direction of the diaphragm; a drive unit that is partially connected to the diaphragm support unit and vibrates the diaphragm; a drive unit support portion that is connected to the drive unit from a direction opposite to the diaphragm and supports a part of the drive unit; a base connected to the drive unit support unit and having an area larger than that of the diaphragm; an outer frame portion connected to the base from the same direction as the drive unit support portion; Equipped with The outer frame is disposed with a gap between the outer periphery of the diaphragm and the outer periphery of the drive unit. An electroacoustic transducer characterized by: <2> a position on the drive unit to which the diaphragm support portion is connected that is outside of a position on the drive unit to which the drive unit support portion is connected; Characterized by <1> The electro-acoustic transducer according to claim 1. <3> A plurality of the diaphragm support portions are provided. Characterized by <1> or <2> The electro-acoustic transducer according to claim 1. <4> The diaphragm support portion is provided so as to be line-symmetrical with respect to a line passing through the center of gravity of the diaphragm within a plane of the diaphragm connected to the diaphragm support portion. Characterized by <3> The electro-acoustic transducer according to claim 1. <5> the drive unit includes a drive plate; the outer frame portion includes a first outer frame portion surrounding the outer periphery of the diaphragm and a second outer frame portion surrounding the outer periphery of the drive portion, the first outer frame portion includes a first layer containing a material similar to that of the diaphragm and a second layer containing a material similar to that of the diaphragm support portion, the second outer frame portion includes a third layer containing the same material as the drive plate and a fourth layer containing the same material as the drive unit support portion; Characterized by <1> Or <4> 10. The electroacoustic transducer according to claim 9, wherein <6> a distance between a connection point between the diaphragm support portion and the drive portion and a center of gravity of the drive portion is longer than a distance between a connection point between the drive portion support portion and the drive portion and a center of gravity of the drive portion; Characterized by <1> Or <5> 10. The electroacoustic transducer according to claim 9, wherein <7> The diaphragm and the first outer frame portion are connected by beams between the diaphragm and the first layer. Characterized by <5> The electro-acoustic transducer according to claim 1. <8> The connection width of the beam with the diaphragm is 1 / 3 or less of the length or diameter of one side of the diaphragm. Characterized by <7> The electro-acoustic transducer according to claim 1. <9> The beam has a constricted portion. Characterized by <7> or <8> The electro-acoustic transducer according to claim 1. <10> The beam is disposed near a connection point between the diaphragm support portion and the diaphragm. Characterized by <7> Or <9> 10. The electroacoustic transducer according to claim 9, wherein <11> At least two beams are provided and arranged to surround the outer periphery of the diaphragm, The sum of the lengths of at least two or more of the beams is equal to or greater than the outer periphery of the diaphragm. Characterized by <7> Or <10> 10. The electroacoustic transducer according to claim 9, wherein <12> a distance from a surface of the outer frame portion located on the opposite side to a surface connected to the base to the base is longer than a distance from the vibration plate to the base; Characterized by <1> Or <11> 10. The electroacoustic transducer according to claim 9, wherein <13> <1> Or <12> A plurality of electro-acoustic transducers according to any one of the above items are provided. An array speaker characterized by the above. <14> <1> Or <12> The electro-acoustic transducer according to any one of A wearable device characterized by: <15> <1> Or <12> The electro-acoustic transducer according to any one of A speaker characterized by: <16> <1> Or <12> The electro-acoustic transducer according to any one of An ultrasonic transmitter characterized by: <17> a first step of forming a diaphragm, a diaphragm support portion connected to a portion of the diaphragm, a first outer frame portion surrounding the periphery of the diaphragm, and beams connecting the diaphragm and the first outer frame portion to obtain a first member; a second step of forming a drive unit that vibrates the diaphragm, a drive unit support that supports a part of the drive unit, and a second outer frame that surrounds the outer periphery of the drive unit to obtain a second member; a third step of connecting the first member and the second member; a fourth step of breaking or removing the beam; Including, the first outer frame portion is disposed with a gap between the outer periphery of the diaphragm and the outer periphery of the drive unit; The beam connects the diaphragm and the first outer frame portion. 10. A method for manufacturing an electroacoustic transducer comprising: <18> After the second step or the third step, connecting the second member to a base having an area larger than that of the diaphragm; Characterized by <17> A method for manufacturing the electro-acoustic transducer according to claim 1. <19> the thickness of the base at a connection point with the second outer frame portion in the vibration direction of the diaphragm is greater than the thickness of a connection point with the drive unit support portion; Characterized by <18> A method for manufacturing the electro-acoustic transducer according to claim 1. [Explanation of symbols]

[0125] 1a Diaphragm 1b Diaphragm support part 2. Drive source 3 Outer frame 4 Drive Plate 5 Drive unit 6 Drive unit support 7. Pedestal 10, 11, 12 Electroacoustic transducer 31 First outer frame part 32 Second outer frame part 31a 1st layer 31b 2nd layer 32a 3rd layer 32b 4th layer 40 Beam 40a Neck 1000 speakers 2000, 3000 wearable devices 5000 ultrasonic transmitter [Prior art documents] [Patent documents]

[0126] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-055474

Claims

1. A diaphragm and a diaphragm support portion connected to a part of the diaphragm in a vibration direction of the diaphragm; a drive unit that is partially connected to the diaphragm support unit and vibrates the diaphragm; a drive unit support portion that is connected to the drive unit from a direction opposite to the diaphragm and supports a part of the drive unit; a base connected to the drive unit support unit and having an area larger than that of the diaphragm; an outer frame portion connected to the base from the same direction as the drive unit support portion; Equipped with The outer frame is disposed with a gap between the outer periphery of the diaphragm and the outer periphery of the drive unit. An electroacoustic transducer characterized by:

2. a position on the drive unit to which the diaphragm support portion is connected that is outside of a position on the drive unit to which the drive unit support portion is connected; 2. The electroacoustic transducer according to claim 1.

3. A plurality of the diaphragm support portions are provided.

2. The electroacoustic transducer according to claim 1.

4. The diaphragm support portion is provided so as to be line-symmetrical with respect to a line passing through the center of gravity of the diaphragm within a plane of the diaphragm connected to the diaphragm support portion.

4. The electroacoustic transducer according to claim 3.

5. the drive unit includes a drive plate; the outer frame portion includes a first outer frame portion surrounding an outer periphery of the diaphragm and a second outer frame portion surrounding an outer periphery of the drive portion, the first outer frame portion includes a first layer containing a material similar to that of the diaphragm and a second layer containing a material similar to that of the diaphragm support portion, the second outer frame portion includes a third layer containing the same material as the drive plate, and a fourth layer containing the same material as the drive unit support portion.

2. The electroacoustic transducer according to claim 1.

6. a distance between a connection point between the diaphragm support portion and the drive portion and a center of gravity of the drive portion is longer than a distance between a connection point between the drive portion support portion and the drive portion and a center of gravity of the drive portion; 2. The electroacoustic transducer according to claim 1.

7. The diaphragm and the first outer frame portion are connected by beams between the diaphragm and the first layer.

6. The electroacoustic transducer according to claim 5.

8. The connection width of the beam with the diaphragm is 1 / 3 or less of the length or diameter of one side of the diaphragm.

8. The electroacoustic transducer according to claim 7.

9. The beam has a constricted portion.

8. The electroacoustic transducer according to claim 7.

10. The beam is disposed near a connection point between the diaphragm support portion and the diaphragm.

8. The electroacoustic transducer according to claim 7.

11. At least two beams are provided and arranged to surround the outer periphery of the diaphragm, The sum of the lengths of at least two or more of the beams is equal to or greater than the outer periphery of the diaphragm.

8. The electroacoustic transducer according to claim 7.

12. a distance from a surface of the outer frame portion located on the opposite side to a surface connected to the base to the base is longer than a distance from the vibration plate to the base; 2. The electroacoustic transducer according to claim 1.

13. A plurality of electro-acoustic transducers according to any one of claims 1 to 12 are provided. An array speaker characterized by the above.

14. An electro-acoustic transducer comprising: an electro-acoustic transducer according to any one of claims 1 to 12; A wearable device characterized by:

15. An electro-acoustic transducer comprising: an electro-acoustic transducer according to any one of claims 1 to 12; A speaker characterized by:

16. An electro-acoustic transducer comprising: an electro-acoustic transducer according to any one of claims 1 to 12; An ultrasonic transmitter characterized by:

17. a first step of forming a diaphragm, a diaphragm support portion connected to a portion of the diaphragm, a first outer frame portion surrounding the periphery of the diaphragm, and beams connecting the diaphragm and the first outer frame portion to obtain a first member; a second step of forming a drive unit that vibrates the diaphragm, a drive unit support that supports a part of the drive unit, and a second outer frame that surrounds an outer periphery of the drive unit to obtain a second member; a third step of connecting the first member and the second member; a fourth step of breaking or removing the beam; Including, the first outer frame portion is disposed with a gap between the outer periphery of the diaphragm and the outer periphery of the drive unit, The beam connects the diaphragm and the first outer frame portion.

10. A method for manufacturing an electroacoustic transducer comprising:

18. After the second step or the third step, connecting the second member to a base having an area larger than that of the diaphragm; 18. The method for manufacturing an electro-acoustic transducer according to claim 17.

19. a thickness of the base at a connection point between the base and the second outer frame portion in the vibration direction of the diaphragm is greater than a thickness of a connection point between the base and the drive unit support portion; 19. The method for manufacturing an electro-acoustic transducer according to claim 18.

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