Electroacoustic converter and headphones

Abstract

This electroacoustic converter comprises: a diaphragm 16 that includes a main dome 22 disposed at the center and a sub-dome 24 that annularly surrounds the main dome; a support portion that fixedly supports an outer periphery 25 of the sub-dome 24; and a voice coil that is provided on the back surface side of the diaphragm 16 to vibrate the diaphragm. The sub-dome 24 includes a plurality of first apexes T1 and a plurality of second apexes T2 that differ in at least one of distance from the outer periphery 25 in the radial direction and position in the height direction, and that are positioned at predetermined intervals in the circumferential direction. The plurality of first apexes T1 and second apexes T2 are positioned on an annular curved surface that is continuous in the circumferential direction.

Description

Electroacoustic transducers and headphones

[0001] The present invention relates to an electro-acoustic transducer and a headphone.

[0002] An electroacoustic transducer provided in a headphone or the like has a diaphragm that is vibrated by a voice coil. The diaphragm has a main dome located in the center and a sub-dome surrounding the main dome. To achieve full-range sound reproduction, the electroacoustic transducer vibrates the diaphragm in a piston motion mode when reproducing low frequencies and in a split vibration mode when reproducing high frequencies, for example.

[0003] JP 2013-251660 A

[0004] The split vibrations described above mainly occur in the sub-dome. For this reason, it is known that when the diaphragm is vibrated in the split vibration mode, peaks and dips occur near the sub-dome's natural frequency. To mitigate the effects of split vibrations, methods such as using sound-absorbing or acoustically resistive materials, or using a material with high internal loss for the diaphragm, could be considered. However, these methods often result in significant side effects (such as a deterioration in sound quality) as they improve split vibrations.

[0005] The present invention has been made in consideration of these points, and has as its object to suppress the occurrence of peaks and dips caused by split vibrations without degrading sound quality.

[0006] In a first aspect of the present invention, there is provided an electro-acoustic transducer comprising: a diaphragm having a main dome located at the center and a sub-dome surrounding the main dome in a ring shape; a support portion that fixes and supports the outer periphery of the sub-dome; and a voice coil that is provided on the back side of the diaphragm and vibrates the diaphragm, wherein the sub-dome has a plurality of first vertices and a plurality of second vertices that differ in at least one of their radial distance from the outer periphery and their positions in the height direction and are positioned at predetermined intervals in the circumferential direction, and the plurality of first vertices and second vertices are positioned on a ring-shaped curved surface that is continuous in the circumferential direction.

[0007] In addition, the distance of the first vertex from the outer peripheral edge may be different from the distance of the second vertex from the outer peripheral edge, and the position of the first vertex in the height direction may be different from the position of the second vertex in the height direction.

[0008] In addition, the distance from the first vertex to the outer peripheral edge may be smaller than the distance from the second vertex to the outer peripheral edge, and the position of the first vertex in the height direction may be higher than the position of the second vertex in the height direction.

[0009] Furthermore, a first curved contour of a first cross section obtained by cutting the sub-dome with a first plane that includes the first vertex and is parallel to the radial direction and the height direction may be connected by the curved surface to a second curved contour of a second cross section obtained by cutting the sub-dome with a second plane that includes the second vertex and is parallel to the radial direction and the height direction.

[0010] The number of the first vertices and the number of the second vertices may each be greater than two and an odd number.

[0011] In addition, the first vertices may be located on the first curved contour of the first cross section at 120 degree intervals in the circumferential direction, and the second vertices may be located on the second curved contour of the second cross section at 120 degree intervals in the circumferential direction.

[0012] The first vertices and the second vertices may be positioned alternately at equal angular intervals in the circumferential direction.

[0013] Furthermore, the first vertex may be a vertex at a first distance that is the shortest from the outer peripheral edge, and the second vertex may be a vertex at a second distance that is the longest from the outer peripheral edge, and multiple vertices between the first vertex and the second vertex in the circumferential direction may be positioned such that the distance from the outer peripheral edge is greater than the first distance but smaller than the second distance, and the distance from the outer peripheral edge changes continuously along the circumferential direction.

[0014] Furthermore, the first vertex may be a vertex of a first height that is the highest in the height direction, the second vertex may be a vertex of a second height that is the lowest in the height direction, and multiple vertices between the first vertex and the second vertex in the circumferential direction may be positioned such that they are greater than the second height but smaller than the first height, and their heights change continuously along the circumferential direction.

[0015] In a second aspect of the present invention, there is provided a headphone having the electro-acoustic transducer described above.

[0016] According to the present invention, it is possible to suppress the occurrence of peaks and dips caused by split vibrations without deteriorating sound quality.

[0017] FIG. 1 is a schematic diagram for explaining the configuration of an electro-acoustic transducer 10 according to one embodiment. FIG. 1 is a schematic diagram for explaining headphones 1. FIG. 2 is a schematic diagram for explaining the planar configuration of a diaphragm 16 according to a first example. FIG. 3 is a schematic perspective view of the diaphragm 16. FIG. 4 is a schematic diagram for explaining the cross-sectional configuration of a sub-dome 24. FIG. 5 is an explanatory diagram for explaining the effect of the shape of the sub-dome 24. FIG. 6 is a schematic diagram for explaining the configuration of a diaphragm 16 according to a second example. FIG. 7 is a schematic diagram for explaining the cross-sectional configuration of a sub-dome 24 according to the second example. FIG. 8 is a schematic diagram for explaining the cross-sectional configuration of a sub-dome 24 according to a third example. FIG. 9 is a schematic diagram for explaining the configuration of a diaphragm 16 according to a fourth example.

[0018] <Configuration of Electroacoustic Transducer> The configuration of an electroacoustic transducer according to one embodiment will be described with reference to FIGS. 1 and 2. FIG.

[0019] Fig. 1 is a schematic diagram illustrating the configuration of an electro-acoustic transducer 10 according to one embodiment. Fig. 2 is a schematic diagram illustrating headphones 1. Here, the electro-acoustic transducer 10 is a driver unit mounted in the headphones 1 shown in Fig. 2. The headphones 1 are a device that combines a device that converts electrical signals output from a playback device or a receiver into sound waves using a sound-generating body placed close to the ear of a user U. Note that the electro-acoustic transducer 10 may be mounted in, for example, earphones instead of the headphones 1.

[0020] As shown in FIG. 1, the electroacoustic transducer 10 includes a yoke 12, a flange portion 14, a diaphragm 16, and a voice coil 18.

[0021] The yoke 12 is formed in a cylindrical shape with a bottom. A magnet is disposed inside the yoke 12. The flange portion 14 is formed in an annular shape on the outer peripheral surface of the yoke 12. The flange portion 14 functions as a support portion that supports the outer peripheral edge side of the diaphragm 16.

[0022] The diaphragm 16 vibrates to radiate sound waves into the air. In order to vibrate at high speed, the diaphragm 16 is made of a very thin and lightweight material. The diaphragm 16 vibrates in a piston motion mode when reproducing low frequencies, and tends to vibrate in a split vibration mode when reproducing high frequencies. As shown in FIG. 1 , the diaphragm 16 has a main dome 22 and a sub-dome 24.

[0023] The main dome 22 is formed in a hemispherical shape and is disposed toward the center of the diaphragm 16. The sub dome 24 surrounds the main dome 22 in an annular shape. The sub dome 24 is connected to the main dome 22 as shown in FIG. 1 . An outer peripheral edge 25 of the sub dome 24 is fixedly supported by the flange portion 14.

[0024] The voice coil 18 has the function of converting an audio signal into vibration. The voice coil 18 is provided on the rear side of the diaphragm 16 and vibrates the diaphragm 16. The voice coil 18 is in contact with the connecting portion of the main dome 22 and the sub-dome 24. The voice coil 18 vibrates the diaphragm 16 to achieve full-range sound reproduction.

[0025] Incidentally, the divided vibration is mainly generated in the sub-dome 24. For this reason, it is known that when the diaphragm is vibrated in the divided vibration mode, peaks and dips occur near the natural frequency of the sub-dome 24 (especially in the high frequency range).

[0026] To suppress the effects of split vibration, methods have been considered, such as using a material with high internal loss for the diaphragm 16 or using sound-absorbing or acoustically resistant materials. However, these methods often result in significant side effects (such as deterioration in sound quality) when reducing split vibration. Specifically, when a material with high internal loss, such as paper, polyurethane, or liquid crystal polymer, is used for the diaphragm 16, peak and dip suppression can be expected, but the sound transmission characteristics are slowed, resulting in the sacrifice of transients, sound sharpness, and a sense of speed. Furthermore, when low-resilience urethane is used as a sound-absorbing material inside the housing of the headphones 1, peak and dip suppression can also be expected, but transients, sound sharpness, and a sense of speed are sacrificed. Furthermore, when an acoustically resistant material is attached to the front of the diaphragm 16, peak and dip suppression can also be expected, but the sound quality becomes muddy and loses clarity.

[0027] In contrast to this, in this embodiment, by devising the surface shape of the sub-dome 24 of the diaphragm 16 (details will be described later), it is possible to suppress the occurrence of peaks and dips caused by split vibrations without degrading sound quality.

[0028] <Detailed Configuration of Diaphragm> The detailed configuration of the sub-dome 24 of the diaphragm 16 will be described below using a number of examples as examples.

[0029] First Embodiment First, the detailed configuration of the sub-dome 24 according to the first embodiment will be described with reference to FIGS.

[0030] Fig. 3 is a schematic diagram illustrating the planar configuration of the diaphragm 16 according to the first embodiment. Fig. 4 is a schematic perspective view of the diaphragm 16. Fig. 5 is a schematic diagram illustrating the cross-sectional configuration of the sub-dome 24. Note that Fig. 5(a) shows a schematic configuration of the A-A cross section of Fig. 3, and Fig. 5(b) shows a schematic configuration of the B-B cross section of Fig. 3.

[0031] As shown in Fig. 3, the sub dome 24 is formed so as to surround the outside of the main dome 22. The sub dome 24 is formed so that the curved cross section continues along the circumferential direction. That is, as shown in Fig. 4, the surface of the sub dome 24 is smoothly connected in the circumferential direction, and there are no sharply uneven portions on the surface.

[0032] In Figure 3, the position of the apex of the sub-dome 24 is indicated by a dashed line T. The apex indicated by the dashed line T is located on a circular curved surface that is continuous in the circumferential direction. As can be seen from Figure 3, the radial position of the apex indicated by the dashed line T varies in the circumferential direction. On the other hand, the height of the apex indicated by the dashed line T is the same in the circumferential direction.

[0033] Of the vertices of the sub dome 24, the first vertex T1 is the vertex that is the shortest distance from the outer peripheral edge 25 of the sub dome 24 in the radial direction, and the vertex T2 is the vertex that is also the longest distance from the outer peripheral edge 25 of the sub dome 24 in the radial direction. Specifically, the distance from the outer peripheral edge 25 of the first vertex T1 is X1 as shown in FIG. 5( a), and the distance from the outer peripheral edge 25 of the vertex T2 is X2 as shown in FIG. 5( b). In this way, the sub dome 24 has a plurality of first vertices T1 and second vertices T2 that are different distances from the outer peripheral edge 25 in the radial direction. The height of the first vertex T1 and the height of the second vertex T2 are the same.

[0034] Furthermore, the distance from the outer peripheral edge 25 to the apex between the first apex T1 and the second apex T2 in the circumferential direction varies continuously along the circumferential direction and is greater than X1 and less than X2. Since the sub dome 24 has multiple apexes at different distances from the outer peripheral edge 25 in this manner, the cross-sectional configuration (in other words, the surface shape) of the sub dome 24 varies along the circumferential direction, and the natural frequency varies for each part of the sub dome 24, thereby dispersing the resonant frequency of the sub dome 24. As a result, the occurrence of peaks and dips in the high-frequency range of the sub dome 24 can be suppressed.

[0035] The multiple first vertices T1 and second vertices T2 are located at predetermined intervals in the circumferential direction of the diaphragm 16. Specifically, the first vertices T1 are located at 120-degree intervals in the circumferential direction. Similarly, the second vertices T2 are located at 120-degree intervals in the circumferential direction. Furthermore, the first vertices T1 and the second vertices T2 are located alternately at equal angular intervals in the circumferential direction. Specifically, as shown in FIG. 3 , three first vertices T1 and three second vertices T2 are located alternately at 60-degree intervals.

[0036] 5A shows a first curved contour C1 including a first vertex T1 of the sub dome 24. The first curved contour C1 is the surface contour of the sub dome 24 in a first cross section obtained by cutting the sub dome 24 along a first plane (the first plane is a plane passing through the center of the diaphragm 16 and the first vertex T1) that is parallel to the radial direction and height direction of the diaphragm 16. As can be seen from FIG. 5A, the first curved contour C1 is continuous and has no irregularities in the radial direction.

[0037] 5B shows a second curved contour C2 including a second vertex T2 of the sub dome 24. The second curved contour C2 is the surface contour of the sub dome 24 in a second cross section obtained by cutting the sub dome 24 along a second plane parallel to the radial and height directions of the diaphragm 16 (the second plane is a plane passing through the center of the diaphragm 16 and the second vertex T2, and is a plane rotated by a predetermined angle in the circumferential direction with respect to the first plane). As can be seen from FIG. 5B, the second curved contour C2 is continuous and has no irregularities in the radial direction.

[0038] 5( a) and 5(b), the shape of the first curved contour C1 is different from the shape of the second curved contour C2. Because the shapes of the first curved contour C1 and the second curved contour C2 are different in this way, the natural frequency of the portion of the sub dome 24 that corresponds to the first curved contour C1 is different from the natural frequency of the portion of the sub dome 24 that corresponds to the second curved contour C2, making it easier to distribute the resonant frequency of the sub dome 24.

[0039] The first curved contour C1 is located on cross section A-A in Figure 3, and therefore is positioned at 120-degree intervals in the circumferential direction of the sub-dome 24. Similarly, the second curved contour C2 is located on cross section B-B in Figure 3, and therefore is positioned at 120-degree intervals in the circumferential direction of the sub-dome 24. Furthermore, the first curved contour C1 and the second curved contour C2 are connected by a curved surface that forms the surface of the sub-dome 24 (see Figure 4). Because the first curved contour C1 and the second curved contour C2 are smoothly connected by this curved surface, the natural frequency varies for each part of the sub-dome 24, and therefore the resonant frequency of the diaphragm 16 is further dispersed, thereby suppressing the occurrence of peaks and dips.

[0040] FIG. 6 is an explanatory diagram illustrating the effect of the shape of the sub-dome 24. In FIG. 6, the frequency characteristics of the comparative example are shown by a dotted line, and the frequency characteristics of the first embodiment are shown by a solid line. Unlike the sub-dome 24 of this embodiment, the comparative example has the sub-dome apex at the same radial and vertical positions. In this case, it can be seen that peaks and dips occur in the high-frequency range surrounded by circles P1 and P2 in FIG. 6. On the other hand, it is clear that the sub-dome 24 of the first embodiment suppresses peaks and dips in the high-frequency range compared to the comparative example. Furthermore, the first embodiment does not use sound-absorbing or acoustically resistive materials, nor does it use a material with high internal loss for the diaphragm 16, so side effects such as deterioration of sound quality do not occur. As a result, the first embodiment can suppress peaks and dips in the high-frequency range caused by split vibrations without deteriorating sound quality.

[0041] Second Example A detailed configuration of a sub-dome 24 according to a second example will be described with reference to FIGS.

[0042] Fig. 7 is a schematic diagram illustrating the configuration of the diaphragm 16 according to the second embodiment. Fig. 8 is a schematic diagram illustrating the cross-sectional configuration of the sub-dome 24 according to the second embodiment. Fig. 8(a) shows a schematic configuration of the A-A cross section of Fig. 7, and Fig. 8(b) shows a schematic configuration of the B-B cross section of Fig. 7.

[0043] Like the sub-dome 24 of the first embodiment described above, the sub-dome 24 of the second embodiment is formed so as to surround the outside of the main dome 22, and the surface of the sub-dome 24 is smoothly continuous in the circumferential direction (there are no sharply uneven portions on the surface).

[0044] In Figure 7, the apexes of the sub domes 24 are indicated by dashed lines T. As can be seen from Figure 7, the radial positions of the apexes indicated by dashed lines T are the same in the circumferential direction. In other words, the distances from the outer peripheral edge 25 of each apex indicated by dashed lines T of the sub domes 24 are the same. On the other hand, the heights of the apexes indicated by dashed lines T vary in the circumferential direction.

[0045] Of the vertices of the sub dome 24, the first vertex T1 is the vertex located at the highest position in the height direction, and the second vertex T2 is the vertex located at the lowest position in the height direction. Specifically, the height of the first vertex T1 from the outer peripheral edge 25 is Y1 as shown in FIG. 8( a), and the height of the second vertex T2 from the outer peripheral edge 25 is Y2 as shown in FIG. 8( b). In this way, the sub dome 24 has a plurality of first vertices T1 and second vertices T2 located at different positions in the height direction. The first vertices T1 and second vertices T2 of the sub dome 24 are alternately positioned at 60-degree intervals in the circumferential direction.

[0046] Furthermore, the height position of the apex between the first apex T1 and the second apex T2 in the height direction varies continuously along the circumferential direction and is greater than Y2 and less than Y1. By having multiple apexes at different heights in the sub dome 24, the cross-sectional configuration of the sub dome 24 varies along the circumferential direction, and the natural frequency varies for each part of the sub dome 24. This distributes the resonant frequency of the sub dome 24, thereby suppressing the occurrence of peaks and dips in the high-frequency range of the sub dome 24.

[0047] The first vertex T1 of the sub dome 24 is located on the first curved contour C1 as shown in Figure 8(a), and the second vertex T2 is located on the second curved contour C2 as shown in Figure 8(b). The first curved contour C1 is located on cross section A-A in Figure 7, and therefore is located at 120-degree intervals in the circumferential direction of the sub dome 24. Similarly, the second curved contour C2 is located on cross section B-B in Figure 7, and therefore is located at 120-degree intervals in the circumferential direction. The first curved contour C1 and second curved contour C2 of the sub dome 24 are connected by a curved surface that forms the surface of the sub dome 24.

[0048] In the second embodiment, as in the first embodiment, peaks and dips in the high frequency range are suppressed (see FIG. 6). Furthermore, the material of the sub-dome 24 in the second embodiment is the same as that of the sub-dome 24 in the first embodiment, and no sound-absorbing or acoustically resistant material is used, nor is a material with high internal loss used for the diaphragm 16, so side effects such as deterioration of sound quality do not occur. As a result, in the second embodiment as well, the occurrence of peaks and dips due to split vibrations can be suppressed without deterioration of sound quality.

[0049] Third Example A detailed configuration of a sub-dome 24 according to a third example will be described with reference to FIG.

[0050] 9A and 9B are schematic diagrams illustrating the cross-sectional configuration of the sub dome 24 according to the third embodiment. Fig. 9A shows a first curved contour C1 of the sub dome 24, and Fig. 9B shows a second curved contour C2 of the sub dome 24. The first curved contour C1 is the contour of the sub dome 24 at the A-A cross section in Fig. 3, and the second curved contour C2 is the contour of the sub dome 24 at the B-B cross section in Fig. 3. Therefore, the first curved contour C1 and the second curved contour C2 are positioned at 120-degree intervals in the circumferential direction.

[0051] The surface of the sub-dome 24 of the third embodiment is smoothly continuous in the circumferential direction, and does not have any sharply uneven portions on the surface, similar to the sub-dome 24 of the first embodiment shown in Fig. 4. The first apex T1 and the second apex T2 of the sub-dome 24 of the third embodiment are a combination of the first apex T1 and the second apex T2 of the first and second embodiments.

[0052] The first vertex T1 is located on the first curved contour C1 as shown in Fig. 9(a), and the second vertex T2 is located on the second curved contour C2 as shown in Fig. 9(b). Therefore, the first vertices T1 and the second vertices T2 are alternately located at 60-degree intervals in the circumferential direction.

[0053] Furthermore, in the third embodiment, as shown in Figures 9(a) and 9(b), the distance from the outer peripheral edge 25 of the first vertex T1 of the sub-dome 24 is different from the distance from the outer peripheral edge 25 of the second vertex T2, and the position of the first vertex T1 in the height direction is different from the position of the second vertex T2 in the height direction.

[0054] Furthermore, the distance from the outer peripheral edge 25 to the first vertex T1 is smaller than the distance from the outer peripheral edge to the second vertex T2, and the position in the height direction of the first vertex T1 is higher than the position in the height direction of the second vertex T2. Specifically, of the vertices of the sub dome 24, the first vertex T1 is the vertex that is closest in the radial direction to the outer peripheral edge 25 of the sub dome 24 and is the vertex that is at the highest position in the height direction. On the other hand, the second vertex T2 is the vertex that is farthest in the radial direction from the outer peripheral edge 25 of the sub dome 24 and is the vertex that is at the lowest position in the height direction.

[0055] In the third embodiment, the first vertex T1 and the second vertex T2 are at different distances from the outer peripheral edge 25, and the first vertex T1 and the second vertex T2 are at different positions in the height direction, so that the surface of the sub-dome 24 has a more complex curve, and therefore peaks and dips in the high frequency range can be more effectively suppressed than in the first and second embodiments.

[0056] Fourth Embodiment A detailed configuration of a sub-dome 24 according to a fourth embodiment will be described with reference to FIG.

[0057] 10 is a schematic diagram illustrating the configuration of a diaphragm 16 according to a fourth embodiment. In the first to third embodiments described above, the first curved contour C1, on which the first vertex T1 is located, and the second curved contour C2, on which the second vertex T2 is located, are positioned at intervals of 120 degrees in the circumferential direction. In contrast, the fourth embodiment differs in that the intervals between the first curved contour C1 and the second curved contour C2 are smaller than 120 degrees.

[0058] The first curved contours C1 according to the fourth embodiment are located on cross section A-A in Fig. 10, and are spaced at 72-degree intervals in the circumferential direction of the sub dome 24. The second curved contours C2 are located on cross section B-B in Fig. 10, and are spaced at 72-degree intervals in the circumferential direction of the sub dome 24. Therefore, the number of first vertices T1 and second vertices T2 is five each.

[0059] In the first to fourth embodiments, it is desirable that the number of first vertices T1 and second vertices T2 is an odd number greater than 2. When the number of first vertices T1 and second vertices T2 is an odd number, the occurrence of abnormal vibration modes in the low frequency range caused by rolling (fluttering) when the diaphragm 16 vibrates can be suppressed compared to when the number of first vertices T1 and second vertices T2 is an even number (specifically, 2).

[0060] More preferably, the number of first vertices T1 and second vertices T2 is 3 or 5. If the number of first vertices T1 and second vertices T2 is 7 or more, the first vertices T1 and the second vertices T2 will be close to each other, and the range of the curved surface between the first vertex T1 and the second vertex T2 will be narrow.

[0061] In the above description, the number of first vertices T1 and second vertices T2 is three or five, but this is not limiting. For example, the number of first vertices T1 and second vertices T2 may be four.

[0062] <Effects of the Present Embodiment> The sub-dome 24 of the electro-acoustic transducer 10 of the present embodiment described above has a plurality of first vertices T1 and a plurality of second vertices T2 that are spaced apart in the circumferential direction and that differ in at least one of their radial distance from the outer peripheral edge 25 and their height position. The plurality of first vertices T1 and second vertices T2 are located on a circular curved surface that is continuous in the circumferential direction. The distance from the outer peripheral edge 25 and their height position of the vertices of the sub-dome 24 are factors that determine the resonant frequency and split resonance mode of the sub-dome 24. Therefore, by shaping the sub-dome 24 so that the first vertices T1 and the second vertices T2 are located on the surface and that differ in at least one of their distance from the outer peripheral edge 25 and their height position, the natural frequency varies for each portion of the sub-dome 24, and the resonant frequency is dispersed. As a result, the occurrence of peaks and dips in the high-frequency range due to split vibrations can be suppressed without degrading sound quality.

[0063] The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments, and various modifications and changes are possible within the scope of the gist of the present invention. For example, all or part of the device can be configured by functionally or physically distributing or integrating in any unit. Furthermore, new embodiments resulting from any combination of multiple embodiments are also included in the embodiments of the present invention. The effects of the new embodiments resulting from the combination also have the effects of the original embodiments.

[0064] REFERENCE SIGNS LIST 1 headphones 10 electroacoustic transducer 14 flange portion 16 diaphragm 18 voice coil 22 main dome 24 sub-dome 25 outer periphery T1 first vertex T2 second vertex C1 first curved contour C2 second curved contour

Claims

1. a diaphragm having a main dome disposed at the center and a sub-dome surrounding the main dome in an annular shape and having inner and outer peripheries each having a predetermined radius; A support portion that fixes and supports an outer peripheral edge of the sub-dome; A voice coil provided on a rear side of the diaphragm to vibrate the diaphragm; Equipped with the sub-dome has a plurality of first vertices and a plurality of second vertices that are different in at least one of a distance from the outer circumferential edge in a radial direction and a position in a height direction and are positioned at a predetermined interval in a circumferential direction, The plurality of first vertices and second vertices are located on an annular curved surface that is continuous in the circumferential direction. Electroacoustic transducer.

2. a distance of the first apex from the outer periphery is different from a distance of the second apex from the outer periphery; A position of the first vertex in the height direction is different from a position of the second vertex in the height direction.

2. The electroacoustic transducer according to claim 1.

3. a distance of the first vertex from the outer periphery is smaller than a distance of the second vertex from the outer periphery; A position of the first vertex in the height direction is higher than a position of the second vertex in the height direction.

3. The electroacoustic transducer according to claim 2.

4. a first curved contour of a first cross section obtained by cutting the sub-dome with a first plane including the first apex and parallel to the radial direction and the height direction; the second apex is included, and the second curved contour of a second cross section obtained by cutting the sub-dome along a second plane parallel to the radial direction and the height direction is connected to the second curved contour by the curved surface; 2. The electroacoustic transducer according to claim 1.

5. the number of the first vertices and the number of the second vertices are each greater than 2 and an odd number; 2. The electroacoustic transducer according to claim 1.

6. The first vertices are located on the first curved contour of the first cross section at 120 degree intervals in the circumferential direction, The second vertices are located on the second curved contour of the second cross section at 120 degree intervals in the circumferential direction, 5. The electroacoustic transducer according to claim 4.

7. The first vertices and the second vertices are alternately positioned at equal angular intervals in the circumferential direction.

2. The electroacoustic transducer according to claim 1.

8. the first vertex is a vertex that is a first distance shortest from the outer periphery, the second apex is a apex at a second distance that is the longest from the outer periphery, A plurality of vertices between the first vertex and the second vertex in the circumferential direction are greater than the first distance and smaller than the second distance, and are positioned such that the distance from the outer circumferential edge changes continuously along the circumferential direction.

2. The electroacoustic transducer according to claim 1.

9. The first vertex is a vertex having a first height that is the highest in the height direction, the second vertex is a vertex at a second height that is the lowest in the height direction, A plurality of vertices between the first vertex and the second vertex in the circumferential direction are positioned such that the height is greater than the second height but smaller than the first height, and the heights change continuously along the circumferential direction.

2. The electroacoustic transducer according to claim 1.

10. A headphone comprising the electroacoustic transducer according to claim 1.