Electroacoustic transducer and headphone

Abstract

The electro-acoustic transducer includes: a diaphragm (16) including a main dome (22) arranged centrally and a secondary dome (24) annularly surrounding the main dome; a support part that fixedly supports the outer periphery (25) of the sub dome (24); and a voice coil provided on the rear surface side of the diaphragm (16) so as to vibrate the diaphragm. The sub-dome (24) includes a plurality of first vertices (T1) and a plurality of second vertices (T2), which differ in at least one of a distance from the outer periphery (25) in the radial direction and a position in the height direction, and are positioned at predetermined intervals in the circumferential direction. A plurality of first vertices (T1) and a plurality of second vertices (T2) are positioned on an annular curved surface continuous in the circumferential direction.

Description

Technical Field

[0001] The invention relates to an electroacoustic transducer and a headphone. Background Art

[0002] An electroacoustic transducer provided in a headphone or the like includes a diaphragm vibrated by a voice coil. The diaphragm has a main dome arranged in a central portion and a sub-dome surrounding the main dome. For example, in order to achieve full-range sound reproduction, the electroacoustic transducer vibrates the diaphragm in a piston motion mode during low-frequency reproduction, and vibrates the diaphragm in a split vibration mode during high-frequency reproduction.

[0003] Prior art

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2013-251660 Summary of the invention

[0006] Problem that the invention aims to solve

[0007] The above-mentioned split vibration mainly occurs in the sub-dome. Therefore, it is known that when the diaphragm vibrates in the split vibration mode, both the peak and the trough occur near the natural frequency of the sub-dome. In order to suppress the influence of the split vibration, methods such as using sound absorbing materials, sound-blocking materials, or using materials with high internal loss for the diaphragm can be considered, but when this method is used, while the split vibration is improved, significant negative effects (such as deterioration of sound quality) will occur.

[0008] The present invention focuses on these matters, and an object of the present invention is to suppress the occurrence of peaks and valleys due to split vibration without deteriorating the sound quality.

[0009] Solutions for solving problems

[0010] A first aspect of the present invention provides an electroacoustic transducer comprising: a diaphragm having a main dome arranged in a central portion and a sub-dome annularly surrounding the main dome; a support portion fixedly supporting the outer peripheral edge of the sub-dome; and a voice coil disposed on the back side of the diaphragm and causing the diaphragm to vibrate, wherein the sub-dome has a plurality of first vertices and a plurality of second vertices, the first vertices and the second vertices being different in at least one of (i) a distance from the outer peripheral edge in a radial direction and (ii) a position in a height direction, and being located at predetermined intervals in a circumferential direction, and the plurality of first vertices and the plurality of second vertices being located on an annular curved surface continuous in the circumferential direction.

[0011] A distance from the outer peripheral edge to the first vertex may be different from a distance from the outer peripheral edge to the second vertex, and a position of the first vertex in the height direction may be different from a position of the second vertex in the height direction.

[0012] A distance from the outer peripheral edge to the first vertex may be smaller than a distance from the outer peripheral edge to the second vertex, and a position of the first vertex in the height direction may be higher than a position of the second vertex in the height direction.

[0013] The first curved profile of the first cross-section can be connected to the second curved profile of the second cross-section through the curved surface, the first cross-section including the first vertex and obtained by cutting the secondary dome along a first plane parallel to the radial and height directions, and the second cross-section including the second vertex and obtained by cutting the secondary dome along a second plane parallel to the radial and height directions.

[0014] The number of the first vertices and the number of the second vertices may both be greater than 2 and be an odd number.

[0015] Each of the first vertices may be located on the first curved contour of the first cross section at intervals of 120 degrees in the circumferential direction, and each of the second vertices may be located on the second curved contour of the second cross section at intervals of 120 degrees in the circumferential direction.

[0016] The first vertices and the second vertices may be alternately located at equal angular intervals in the circumferential direction.

[0017] The first vertex may be a vertex at a shortest first distance from the peripheral edge, the second vertex may be a vertex at a longest second distance from the peripheral edge, and a plurality of vertices between the first vertex and the second vertex in the circumferential direction may have a distance greater than the first distance and less than the second distance, and may be positioned so that the distance from the peripheral edge changes continuously along the circumference.

[0018] The first vertex may be a vertex located at the highest first height in the height direction, the second vertex may have the lowest second height in the height direction, and a plurality of vertices between the first vertex and the second vertex in the circumferential direction may have heights higher than the second height and lower than the first height, and be positioned so that the height changes continuously along the circumferential direction.

[0019] A second aspect of the present invention provides a headphone comprising the above electroacoustic transducer.

[0020] Effects of the Invention

[0021] According to the present invention, the occurrence of peaks and valleys due to split vibration can be suppressed without deteriorating the sound quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic diagram illustrating the configuration of an electroacoustic transducer 10 according to one embodiment.

[0023] Figure 2 1 is a schematic diagram for explaining the headphone 1 .

[0024] Figure 3 1 is a schematic diagram for explaining a planar configuration of the diaphragm 16 according to the first embodiment.

[0025] Figure 4 is a schematic perspective view of the diaphragm 16 .

[0026] Figure 5 It is a schematic diagram for explaining the cross-sectional structure of the sub-dome 24 .

[0027] Figure 6 2 is a schematic diagram for explaining the influence of the shape of the sub-dome 24 .

[0028] Figure 7 1 is a schematic diagram for explaining the configuration of the diaphragm 16 according to the second embodiment.

[0029] Figure 8 2 is a schematic diagram for explaining a cross-sectional configuration of a sub-dome 24 according to the second embodiment.

[0030] Fig. 9 2 is a schematic diagram for explaining a cross-sectional configuration of a sub-dome 24 according to the third embodiment.

[0031] Fig.10 1 is a schematic diagram for explaining the configuration of the diaphragm 16 according to the fourth embodiment. DETAILED DESCRIPTION

[0032] <Structure of electroacoustic transducer>

[0033] Will refer to Figure 1 and Figure 2 The configuration of an electroacoustic transducer according to one embodiment is described.

[0034] Figure 1 is a schematic diagram illustrating the configuration of an electroacoustic transducer 10 according to one embodiment. Figure 2 1 is a schematic diagram for explaining the headphone 1. The electroacoustic transducer 10 is mounted on Figure 2The driver unit in the headphone 1 shown. The headphone 1 is a device that combines a device that converts an electrical signal output from a playback device or a receiver into a sound wave using a sound generator near the ear of the user U. The electroacoustic transducer 10 may also be installed in, for example, an earphone instead of the headphone 1.

[0035] like Figure 1 As shown, the electro-acoustic transducer 10 includes a yoke 12 , a flange portion 14 , a diaphragm 16 , and a voice coil 18 .

[0036] The yoke 12 is formed in a bottomed cylindrical shape. The magnet is arranged 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 supporting portion that supports the outer peripheral edge of the diaphragm 16.

[0037] The diaphragm 16 vibrates to emit sound waves into the air. The diaphragm 16 is made of a very thin and light material so as to vibrate at high speed. The diaphragm 16 tends to vibrate in a piston motion mode during low frequency reproduction, and tends to vibrate in a split vibration mode during high frequency reproduction. Figure 1 As shown, the diaphragm 16 has a primary dome 22 and a secondary dome 24 .

[0038] The main dome 22 is formed in a hemispherical shape and is arranged in the central portion of the diaphragm 16. The sub-dome 24 surrounds the main dome 22 in an annular shape. Figure 1 As shown, the auxiliary dome 24 is connected to the main dome 22. The outer peripheral edge 25 of the auxiliary dome 24 is fixedly supported by the flange portion 14.

[0039] The voice coil 18 has a function of converting a sound signal into vibration. The voice coil 18 is provided on the back side of the diaphragm 16 and vibrates the diaphragm 16. The voice coil 18 is in contact with the connection between the main dome 22 and the sub-dome 24. The voice coil 18 vibrates the diaphragm 16 to achieve full-range sound reproduction.

[0040] The split vibration is mainly generated in the sub-dome 24. Therefore, it is known that when the diaphragm vibrates in the split vibration mode, peaks and valleys occur near the natural frequency of the sub-dome 24 (particularly, in the high frequency range).

[0041] In order to suppress the influence of split vibration, methods of using materials with high internal loss for the diaphragm 16 or using sound-absorbing materials, sound-blocking materials, etc. are considered, but significant negative effects (such as deterioration of sound quality) will occur while the split vibration is improved. Specifically, when materials with high internal loss such as paper, polyurethane, liquid crystal polymer, etc. are used for the diaphragm 16, it can be expected to suppress peaks and troughs, but this will damage the so-called transient, sound sharpness and sense of speed because the sound transmission characteristics are slowed down. In addition, when low-elasticity polyurethane is used as a sound-absorbing material inside the shell of the headphone 1, it can be expected to suppress peaks and troughs, but this will damage transients, sound sharpness and sense of speed. In addition, when a sound-blocking material is attached to the front of the diaphragm 16, although it can be expected to suppress peaks and troughs, the sound quality will become dull and clarity will be lost.

[0042] In contrast, in the present embodiment, by designing the surface shape of the sub-dome 24 of the diaphragm 16 , the occurrence of peaks and troughs due to split vibration can be suppressed without deteriorating the sound quality, as will be described in detail later.

[0043] <Detailed structure of the diaphragm>

[0044] Hereinafter, the detailed configuration of the sub-dome 24 of the diaphragm 16 will be described with reference to a plurality of embodiments as examples.

[0045] (First Embodiment)

[0046] First, refer to Figures 3 to 5 The detailed structure of the sub-dome 24 according to the first embodiment will be described.

[0047] Figure 3 1 is a schematic diagram for explaining a planar configuration of the diaphragm 16 according to the first embodiment. Figure 4 is a schematic perspective view of the diaphragm 16 . Figure 5 It is a schematic diagram for explaining the cross-sectional structure of the sub-dome 24 . Figure 5 (a) shows Figure 3 Schematic construction of section AA, Figure 5 (b) shows Figure 3 Schematic construction of section BB.

[0048] like Figure 3 As shown in FIG. 1 , the secondary dome 24 is formed to extend around the outer side of the primary dome 22. The secondary dome 24 is formed so that its curved cross section is continuous along the circumferential direction. Figure 4 As shown, the surface of the secondary dome 24 is smoothly connected in the circumferential direction, and there are no steep concave and convex parts on the surface.

[0049] exist Figure 3In FIG. 1 , the position of the vertex of the secondary dome 24 is indicated by a dotted line T. The vertex indicated by the dotted line T is located on the annular curved surface that is continuous in the circumferential direction. Figure 3 As can be seen in FIG. 1 , the position of the apex indicated by the dotted line T in the radial direction changes along the circumferential direction. On the other hand, the height of the apex indicated by the dotted line T is the same in the circumferential direction.

[0050] Among the vertices of the secondary dome 24, the first vertex T1 is the shortest distance from the outer peripheral edge 25 of the secondary dome 24 in the radial direction, and the vertex T2 is the longest distance from the outer peripheral edge 25 of the secondary dome 24 in the radial direction. Figure 5 As shown in (a), the distance from the outer peripheral edge 25 to the first vertex T1 is X1, and as Figure 5 As shown in (b), the distance from the peripheral edge 25 to the vertex T2 is X2. In this way, the secondary dome 24 has a plurality of first vertices T1 and second vertices T2, each of which has a different distance from the peripheral edge 25 in the radial direction. The height of the first vertex T1 is the same as the height of the second vertex T2.

[0051] The distance between the vertices between the first vertex T1 and the second vertex T2 in the circumferential direction and the outer peripheral edge 25 changes continuously along the circumferential direction and is greater than X1 and less than X2. Since the sub-dome 24 has a plurality of vertices having different distances from the outer peripheral edge 25 as described above, the cross-sectional configuration (in other words, the surface shape) of the sub-dome 24 changes along the circumferential direction, causing the natural frequency to change throughout different parts of the sub-dome 24, which disperses the resonant frequency of the sub-dome 24. Therefore, the occurrence of peaks and troughs in the high frequency range of the sub-dome 24 can be suppressed.

[0052] A plurality of first vertices T1 and a plurality of second vertices T2 are located at predetermined intervals in the circumferential direction of the diaphragm 16. Specifically, the first vertices T1 are located at intervals of 120 degrees in the circumferential direction. Similarly, the second vertices T2 are also located at intervals of 120 degrees in the circumferential direction. The first vertices T1 and the second vertices T2 are alternately located at equal angular intervals in the circumferential direction. Specifically, as Figure 3 As shown, the three first vertices T1 and the three second vertices T2 are alternately located at intervals of 60 degrees.

[0053] Figure 5 (a) illustrates a first curved profile C1 of the sub-dome 24 including a first vertex T1. The first curved profile C1 is a surface profile of the sub-dome 24 in a first cross section obtained by cutting the sub-dome 24 along a first surface parallel to the radial and height directions of the diaphragm 16. The first surface passes through the center of the diaphragm 16 and the first vertex T1. Figure 5 As can be seen in (a), the first curved profile C1 is continuously connected in the radial direction without any concave-convex.

[0054] Figure 5(b) illustrates a second curved profile C2 including a second vertex T2 of the secondary dome 24. The second curved profile C2 is a surface profile of the secondary dome 24 in a second cross section obtained by cutting the secondary dome 24 along a second surface parallel to the radial and height directions of the diaphragm 16. The second surface passes through the center and the second vertex T2 of the diaphragm 16 and is rotated by a predetermined angle in the circumferential direction relative to the first surface. Figure 5 As can be seen in (b), the second curved profile C2 is continuously connected in the radial direction without any concave-convex.

[0055] like Figure 5 (a) and Figure 5 As can be seen from the comparison between (b), the shape of the first curved profile C1 is different from the shape of the second curved profile C2. As described above, since the shape of the first curved profile C1 is different from the shape of the second curved profile C2, in the secondary dome 24, the natural frequency of the portion corresponding to the first curved profile C1 and the natural frequency of the portion corresponding to the second curved profile C2 are different, making it easier for the resonant frequency of the secondary dome 24 to disperse.

[0056] Since the plurality of first curved profiles C1 are located Figure 3 At the section AA in the secondary dome 24, they are located at intervals of 120 degrees in the circumferential direction of the secondary dome 24. Similarly, since the plurality of second curved profiles C2 are located Figure 3 The first curved profile C1 and the second curved profile C2 are connected by a curved surface forming the surface of the secondary dome 24 (see Figure 4 ). Since the first curved profile C1 and the second curved profile C2 are smoothly connected by the curved surface in this way, the natural frequencies of the parts of the sub-dome 24 are changed, thereby further dispersing the resonance frequency of the diaphragm 16, and as a result, the occurrence of peaks and troughs can be suppressed.

[0057] Figure 6 2 is an explanatory diagram for explaining the influence of the shape of the sub-dome 24. Figure 6 In FIG. 1 , the dotted line indicates the frequency characteristics of the comparative example, and the solid line indicates the frequency characteristics of the first embodiment. The difference between the sub-dome 24 of the comparative example and the present embodiment is that the positions of the vertices of the sub-dome in the radial direction are the same, and the positions of the vertices in the height direction are also the same. In this case, it can be seen that Figure 6The peaks and troughs occurring in the high-frequency range surrounded by circles P1 and P2 in the figure. On the other hand, in the case of the sub-dome 24 of the first embodiment, it is clear that the peaks and troughs in the high-frequency range are suppressed compared with the case of the comparative example. In addition, in the case of the first embodiment, since no sound absorbing material or sound-resisting material is used, and no material with high internal loss is used for the diaphragm 16, no negative effects such as deterioration of sound quality occur. As a result, in the case of the first embodiment, the occurrence of peaks and troughs in the high-frequency range due to split vibration can be suppressed without deteriorating the sound quality.

[0058] (Second Embodiment)

[0059] Will refer to Figure 7 and Figure 8 The detailed structure of the sub-dome 24 according to the second embodiment will be described.

[0060] Figure 7 1 is a schematic diagram for explaining the configuration of the diaphragm 16 according to the second embodiment. Figure 8 2 is a schematic diagram for explaining a cross-sectional configuration of a sub-dome 24 according to the second embodiment. Figure 8 (a) shows Figure 7 The schematic configuration of section AA, and Figure 8 (b) shows Figure 7 Schematic construction of section BB.

[0061] In a similar manner to the sub-dome 24 of the first embodiment described above, the sub-dome 24 of the second embodiment is also formed to extend around the outside of the main dome 22, and the surface of the sub-dome 24 is smoothly connected in the circumferential direction (there are no steep concavoconvex parts on the surface).

[0062] exist Figure 7 In FIG. 1 , the vertex of the secondary dome 24 is indicated by a dotted line T. Figure 7 It can be seen that the positions of the vertices indicated by the dotted line T in the radial direction are the same in the circumferential direction. That is, the distance from the outer peripheral edge 25 to each vertex indicated by the dotted line T of the secondary dome 24 is the same. On the other hand, the heights of the vertices indicated by the dotted line T are different in the circumferential direction.

[0063] Among the vertices of the secondary dome 24, the first vertex T1 is at the highest position in the height direction, and the second vertex T2 is at the lowest position in the height direction. Specifically, the height from the peripheral edge 25 to the first vertex T1 is Y1, as shown in FIG. Figure 8 As shown in (a), and the height from the outer peripheral edge 25 to the second vertex T2 is Y2, as shown in Figure 8In this way, the secondary dome 24 has a plurality of first vertices T1 and second vertices T2, each of which is located at a different position in the height direction. The first vertices T1 and second vertices T2 of the secondary dome 24 are alternately located at intervals of 60 degrees in the circumferential direction.

[0064] The height direction position of the apex between the first apex T1 and the second apex T2 in the height direction changes continuously along the circumferential direction and is greater than Y2 and less than Y1. As described above, since the plurality of apexes of the sub-dome 24 have different height positions, the cross-sectional configuration of the sub-dome 24 changes along the circumferential direction, causing the natural frequency to change throughout different portions of the sub-dome 24, which disperses the resonant frequency of the sub-dome 24. Therefore, the occurrence of peaks and troughs in the high frequency range of the sub-dome 24 can be suppressed.

[0065] The first vertex T1 of the secondary dome 24 is located at Figure 8 The first curved contour C1 shown in (a) of FIG. 1 is shown in FIG. Figure 8 Since the plurality of first curved profiles C1 are located on the second curved profile C2 shown in (b) of FIG. Figure 7 At the section AA in the secondary dome 24, they are located at intervals of 120 degrees in the circumferential direction of the secondary dome 24. Similarly, since the plurality of second curved profiles C2 are located Figure 7 The first curved profile C1 and the second curved profile C2 of the auxiliary dome 24 are connected by a curved surface forming the surface of the auxiliary dome 24 .

[0066] In the case of the second embodiment, the peaks and valleys in the high frequency range are suppressed in a similar manner to the first embodiment (see Figure 6 ). In addition, the material of the sub-dome 24 of the second embodiment is the same as that of the sub-dome 24 of the first embodiment. Since this design does not require the use of a sound absorbing material or a sound-resisting material or a material with high internal loss for the diaphragm 16, negative effects such as deterioration of sound quality do not occur. As a result, in the second embodiment, the occurrence of peaks and troughs due to split vibration can be suppressed without deteriorating the sound quality.

[0067] (Third Embodiment)

[0068] Will refer to Fig. 9 The detailed structure of the sub-dome 24 according to the third embodiment will be described.

[0069] Fig. 9 2 is a schematic diagram for explaining a cross-sectional configuration of a sub-dome 24 according to the third embodiment. Fig. 9 (a) shows a first curved profile C1 of the secondary dome 24, and Fig. 9(b) shows the second curved profile C2 of the secondary dome 24. The first curved profile C1 is the secondary dome 24 in Figure 3 The second curved profile C2 is the profile of the secondary dome 24 at each position of the AA section in FIG. Figure 3 Therefore, the first curved profiles C1 are located at intervals of 120 degrees in the circumferential direction, and the second curved profiles C2 are also located at intervals of 120 degrees in the circumferential direction.

[0070] and Figure 4 Similarly to the auxiliary dome 24 of the first embodiment shown in , the surface of the auxiliary dome 24 of the third embodiment is smoothly connected in the circumferential direction, and there is no steep concave and convex portion on the surface. The first vertex T1 and the second vertex T2 of the auxiliary dome 24 of the third embodiment are a combination of the first vertex T1 and the second vertex T2 of the first embodiment and the first vertex T1 and the second vertex T2 of the second embodiment.

[0071] The first vertex T1 is located at Fig. 9 The first curved contour C1 shown in (a) of FIG. 1 is shown in FIG. Fig. 9 Therefore, the plurality of first vertices T1 and second vertices T2 are alternately located at intervals of 60 degrees in the circumferential direction.

[0072] In a third embodiment, if Fig. 9 (a) and Fig. 9 As shown in (b), the distance from the outer peripheral edge 25 to the first vertex T1 of the secondary dome 24 is different from the distance from the outer peripheral edge 25 to 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.

[0073] 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 of the first vertex T1 in the height direction is higher than the position of the second vertex T2 in the height direction. Specifically, the first vertex T1 among the vertices of the sub-dome 24 is closest to the outer peripheral edge 25 of the sub-dome 24 in the radial direction and is at the highest position in the height direction. On the other hand, the second vertex T2 is farthest from the outer peripheral edge 25 of the sub-dome 24 in the radial direction and is at the lowest position in the height direction.

[0074] In the case of the third embodiment, since (i) the distances from the outer peripheral edge 25 to the first vertex T1 and the second vertex T2 are different, and (ii) the positions of the first vertex T1 and the second vertex T2 in the height direction are also different, the surface of the sub-dome 24 forms a more complex curved surface, which can more effectively suppress the peaks and troughs in the high-frequency range compared with the first and second embodiments.

[0075] (Fourth Embodiment)

[0076] Will refer to Fig.10 A detailed configuration of the sub-dome 24 according to the fourth embodiment will be described.

[0077] Fig.10 1 is a schematic diagram for explaining the structure of the diaphragm 16 according to the fourth embodiment. In the above-mentioned first to third embodiments, the first curved profile C1 where the first vertex T1 is located and the second curved profile C2 where the second vertex T2 is located are located at intervals of 120 degrees in the circumferential direction. On the other hand, the fourth embodiment is different in that the plurality of first curved profiles C1 and the second curved intervals C2 are less than 120 degrees.

[0078] Since the first curved profile C1 according to the fourth embodiment is located Fig.10 In the cross section AA in FIG. 1 , the first curved profiles C1 are spaced 72 degrees apart in the circumferential direction of the secondary dome 24. In addition, since the second curved profiles C2 are located Fig.10 At the cross section BB in FIG. 2 , the second curved profiles C2 are therefore spaced 72 degrees apart in the circumferential direction of the secondary dome 24. Therefore, the number of the first vertices T1 and the second vertices T2 are both five.

[0079] From the first embodiment to the fourth embodiment, it is desirable that the number of the first vertices T1 and the number of the second vertices T2 are both greater than 2 and are odd numbers. As described above, when the number of the first vertices T1 and the second vertices T2 is an odd number, compared with the case where the number of the first vertices T1 and the second vertices T2 is an even number (specifically, 2), the occurrence of an abnormal vibration mode in the low frequency range due to shaking (clicking) when the diaphragm 16 vibrates can be suppressed.

[0080] More preferably, the number of the first vertices T1 and the number of the second vertices T2 are both 3 or 5. This is because when the number of the first vertices T1 and the second vertices T2 is 7 or more, the first vertices T1 and the second vertices T2 are close to each other, and the range of the curved surface between the first vertices T1 and the second vertices T2 becomes narrower.

[0081] In the above description, the number of the first vertices T1 and the number of the second vertices T2 are both 3 or 5, but the present invention is not limited thereto. For example, the number of the first vertices T1 and the number of the second vertices T2 may both be 4.

[0082] <Effects of Implementation Methods>

[0083] The sub-dome 24 of the electroacoustic transducer 10 of the present embodiment described above has a plurality of first vertices T1 and a plurality of second vertices T2, which are different in at least one of (i) the distance from the outer peripheral edge 25 in the radial direction and (ii) the position in the height direction, and are located at predetermined intervals in the circumferential direction. The plurality of first vertices T1 and the plurality of second vertices T2 are located on an annular curved surface that is continuous in the circumferential direction. Since the vertices from the outer peripheral edge 25 to the sub-dome 24 and the positions of the vertices in the height direction are factors that determine the resonance frequency and the split resonance mode of the sub-dome 24, by forming the sub-dome 24 into a shape in which the first vertices T1 and the second vertices T2 located on the surface are different in at least one of (i) the distance from the outer peripheral edge 25 or (ii) the position in the height direction, the natural frequency throughout different parts of the sub-dome 24 changes, which causes the resonance frequency to become dispersed. As a result, the occurrence of peaks and troughs in the high frequency range due to split vibration can be suppressed without deteriorating the sound quality.

[0084] The present disclosure is explained based on the exemplary embodiments. The technical scope of the present disclosure is not limited to the scope explained in the above embodiments, and various changes and modifications can be made within the scope of the present disclosure. For example, all or part of the device can be constructed as any unit that is functionally or physically dispersed or integrated. In addition, new exemplary embodiments generated by any combination of them are included in the exemplary embodiments of the present disclosure. In addition, the effect of the new exemplary embodiment brought about by the combination also has the effect of the original exemplary embodiment.

[0085] [Explanation of Reference Numerals]

[0086] 1 Headphones

[0087] 10 Electroacoustic transducer

[0088] 14 Flange

[0089] 16 Diaphragm

[0090] 18 Voice Coil

[0091] 22 Main Dome

[0092] 24 domes

[0093] 25 Periphery

[0094] T1 first vertex

[0095] T2 Second vertex

[0096] C1 First bending profile

[0097] C2 Second bending profile

Claims

1. An electroacoustic transducer, comprising: a diaphragm having a main dome disposed at a central portion and a sub-dome annularly surrounding the main dome; a support portion fixedly supporting an outer peripheral edge of the secondary dome; and a voice coil disposed on the back side of the diaphragm and causing the diaphragm to vibrate, wherein: The secondary dome has a plurality of first vertices and a plurality of second vertices, the first vertices and the second vertices are different in at least one of (i) distances from the outer peripheral edge in a radial direction and (ii) positions in a height direction, and are located at predetermined intervals in a circumferential direction, and The plurality of first vertices and the plurality of second vertices are located on an annular curved surface that is continuous in the circumferential direction.

2. The electroacoustic transducer according to claim 1, wherein: A distance from the peripheral edge to the first vertex is different from a distance from the peripheral edge to the second vertex, and The position of the first vertex in the height direction is different from the position of the second vertex in the height direction.

3. The electroacoustic transducer according to claim 2, wherein: The distance from the peripheral edge to the first vertex is less than the distance from the peripheral edge to the second vertex, and The position of the first vertex in the height direction is higher than the position of the second vertex in the height direction.

4. The electroacoustic transducer according to claim 1, wherein: A first curved profile of a first cross-section is connected to a second curved profile of a second cross-section through the curved surface, the first cross-section includes the first vertex and is obtained by cutting the secondary dome along a first plane parallel to the radial and height directions, and the second cross-section includes the second vertex and is obtained by cutting the secondary dome along a second plane parallel to the radial and height directions.

5. The electroacoustic transducer according to claim 1, wherein: The number of the first vertices and the number of the second vertices are both greater than 2 and are odd numbers.

6. The electroacoustic transducer according to claim 4, wherein: Each of the first vertices is located on the first curved profile of the first cross section at intervals of 120 degrees in the circumferential direction, and Each of the second vertices is located at intervals of 120 degrees in the circumferential direction on the second curved contour of the second cross section.

7. The electroacoustic transducer according to claim 1, wherein: The first vertices and the second vertices are alternately located at equal angular intervals in the circumferential direction.

8. The electroacoustic transducer according to claim 1, wherein: The first vertex is a vertex with the shortest first distance from the peripheral edge, The second vertex is the vertex at the longest second distance from the peripheral edge, and A plurality of vertices between the first vertex and the second vertex in the circumferential direction have a distance greater than the first distance and less than the second distance, and are positioned such that a distance from the outer peripheral edge continuously changes along the circumferential direction.

9. The electroacoustic transducer according to claim 1, wherein: The first vertex is a vertex located at a first highest height in the height direction, The second vertex is a vertex located at the second lowest height in the height direction, and A plurality of vertices between the first vertices and the second vertices in the circumferential direction have a height higher than the second height and lower than the first height, and are positioned such that the height continuously changes along the circumferential direction.

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

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