Diaphragm and speaker unit

Abstract

The invention relates to a diaphragm and a speaker unit. Peak drop in a diaphragm is suppressed. A diaphragm (1) in which one axial direction length and the other axial direction length are different in two orthogonal axial directions as viewed from the top, and the diaphragm (1) has a predetermined shape configured by curves on both sides in a longitudinal direction as the one axial direction, the diaphragm (1) including: a first reinforcing portion (3) extending in the longitudinal direction; and a second reinforcing section (4), which is provided adjacent to the first reinforcing section (3) in the lateral direction, and which is a netted concave-convex section.

Description

Technical Field

[0001] The present invention relates to a diaphragm and a speaker unit including the diaphragm. Background Art

[0002] As the shape of a diaphragm for a speaker unit, there are a common perfect circle and an irregular shape that can support TVs and laptop PCs with limited installation space. As the irregular shape, there are an oval shape and an orbital shape (see Figure 28 ). In an irregular-shaped diaphragm, the aspect ratio in the longitudinal and transverse directions is large, and the characteristics of the diaphragm are improved by providing reinforcing ribs along the longitudinal direction to make the stiffness of the entire diaphragm uniform (see Figure 29 ). Each of the above shapes of the diaphragm is the shape seen from the top. However, for linear reinforcing ribs, it is difficult to increase the rigidity of the portion around the ribs by the linear reinforcing ribs. If the width of the ribs becomes wide, the weight balance in the transverse direction is unbalanced, and a large peak drop occurs according to the characteristics.

[0003] To solve the above problems, JP 2021-125869 A describes a diaphragm in which raised ribs with a wide width are provided (see Figure 30 ). However, in a long and narrow diaphragm with a large aspect ratio, the weight balance in the transverse direction is unbalanced, rotational gaps are likely to occur, and further peak drops occur according to the characteristics. In addition, JP 2021-125869 A describes a diaphragm in which a dragonfly vein pattern is provided on the raised ribs (see Figure 31 ). However, the vein pattern further increases the weight in the longitudinal direction and the effect of the raised ribs becomes smaller.

[0004] As described above, in the prior art, there is a problem of peak drop. Summary of the Invention

[0005] An object of the present invention is to suppress peak drop in a diaphragm.

[0006] A diaphragm of the present invention, in the diaphragm, when viewed from the top, the length in one axial direction and the length in the other axial direction are different in two orthogonal axial directions, and the diaphragm has a predetermined shape, the predetermined shape being formed by curves on both sides in the longitudinal direction as one axial direction, the diaphragm including: a first reinforcing portion extending along the longitudinal direction; and a second reinforcing portion disposed adjacent to the first reinforcing portion in the transverse direction, and the second reinforcing portion being a mesh-like concavo-convex portion.

[0007] In the present invention, a first reinforcing portion extending longitudinally and a second reinforcing portion adjacent to the first reinforcing portion and having a reticular concavo-convex portion are provided. Accordingly, (1) the vibration of the edge provided in the diaphragm is suppressed. In addition, (2) the overall stiffness is increased by the first reinforcing portion, and the resonance peaks are effectively dispersed by the second reinforcing portion. According to the present invention, the peak drop in the diaphragm is suppressed by (1) or (2).

[0008] Preferably, the second reinforcing portion mimics the wings of an insect.

[0009] Preferably, the second reinforcing portion is based on data obtained by measuring the actual shape of the wing veins of an insect or data of a Voronoi diagram mimicking the wing veins of an insect.

[0010] Preferably, the second reinforcing portion has a plurality of polygonal convex portions and a plurality of polygonal concave portions. The polygonal concave portions are formed inside these convex portions by the convex portions, and in the plurality of polygonal convex portions, one side of adjacent convex portions is a portion forming two polygons.

[0011] Preferably, the second reinforcing portion extends radially longitudinally from the center.

[0012] Preferably, two second reinforcing portions in the second reinforcing portion are provided across the first reinforcing portion in the transverse direction.

[0013] Preferably, the mesh shapes in the two second reinforcing portions are different from each other.

[0014] Preferably, two sets of the first reinforcing portion and the two second reinforcing portions are provided across the center in the longitudinal direction.

[0015] Preferably, the two second reinforcing portions across the center in the longitudinal direction are symmetric with respect to the center point.

[0016] Preferably, the width of the first reinforcing portion gradually narrows longitudinally from the center in the longitudinal direction.

[0017] Preferably, the aspect ratio of the longitudinal length to the transverse length is not less than 2:1.

[0018] The loudspeaker unit of the present invention includes: a diaphragm; a voice coil connected to an opening of the diaphragm; a dust cap coupled to the voice coil; an edge coupled to the outer periphery of the diaphragm; a frame to which the outer periphery of the edge is fixed; and a magnetic circuit having a magnetic gap in which a coil of the voice coil is disposed and the magnetic circuit is fixed to the frame. Wherein, when viewed from the top, the diaphragm has one axial length and another axial length different in two orthogonal axial directions, and the diaphragm has a predetermined shape, the predetermined shape being formed by curves on both sides in the longitudinal direction as one axial direction. The diaphragm includes: a first reinforcing portion extending along the longitudinal direction; and a second reinforcing portion disposed adjacent to the first reinforcing portion in the transverse direction and having a reticular concavo-convex portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a perspective view showing a diaphragm according to an embodiment of the present invention.

[0020] Figure 2 is a top view showing a diaphragm according to an embodiment of the present invention.

[0021] Figure 3 is a perspective view showing a diaphragm and the like according to an embodiment of the present invention.

[0022] Figure 4 is a perspective view showing a speaker unit according to an embodiment of the present invention.

[0023] Figure 5 is a model diagram showing Comparative Example 1.

[0024] Figure 6 is a model diagram showing Comparative Example 2.

[0025] Figure 7 is a model diagram showing Comparative Example 3.

[0026] Figure 8 is a model diagram showing an Example.

[0027] Figure 9 is a graph showing the frequency characteristics of the Example and Comparative Example 1.

[0028] Figure 10 (a) of is a diagram showing the movement of the model of the Example at 2300 Hz.

[0029] Figure 10 (b) of is a diagram showing the movement of the model of Comparative Example 1 at 2300 Hz.

[0030] Figure 11 (a) of is a diagram showing the movement of the model of the Example at 3200 Hz.

[0031] Figure 11 (b) of is a diagram showing the movement of the model of Comparative Example 1 at 3200 Hz.

[0032] Figure 12 (a) of is a diagram showing the movement of the model of the Example at 9200 Hz.

[0033] Figure 12 (b) of is a diagram showing the movement of the model of Comparative Example 1 at 9200 Hz.

[0034] Figure 13 is a graph showing the frequency characteristics of the Example, Comparative Example 2, and Comparative Example 3.

[0035] Figure 14 (a) shows the movement of the model of the embodiment at 2500 Hz.

[0036] Figure 14 (b) shows the movement of the model of Comparative Example 2 at 2500 Hz.

[0037] Figure 15 (a) shows the movement of the model of the embodiment at 3700 Hz.

[0038] Figure 15 (b) shows the movement of the model of Comparative Example 2 at 3700 Hz.

[0039] Figure 16 (a) shows the longitudinal wavefront of the embodiment at 2300 Hz.

[0040] Figure 16 (b) shows the longitudinal wavefront of Comparative Example 1 at 2300 Hz.

[0041] Figure 17 (a) shows the longitudinal sound pressure distribution of the embodiment at 2300 Hz.

[0042] Figure 17 (b) shows the longitudinal sound pressure distribution of Comparative Example 1 at 2300 Hz.

[0043] Figure 18 (a) shows the longitudinal wavefront of the embodiment at 3200 Hz.

[0044] Figure 18 (b) shows the longitudinal wavefront of Comparative Example 1 at 3200 Hz.

[0045] Figure 19 (a) shows the longitudinal sound pressure distribution of the embodiment at 3200 Hz.

[0046] Figure 19 (b) shows the longitudinal sound pressure distribution of Comparative Example 1 at 3200 Hz.

[0047] Figure 20 (a) shows the longitudinal wavefront of the embodiment at 9200 Hz.

[0048] Figure 20 (b) shows the longitudinal wavefront of Comparative Example 1 at 9200 Hz.

[0049] Figure 21 (a) shows the longitudinal sound pressure distribution of the embodiment at 9200 Hz.

[0050] Figure 21 (b) shows the longitudinal sound pressure distribution of Comparative Example 1 at 9200 Hz.

[0051] Figure 22 (a) shows the wavefront of the longitudinal embodiment of the example at 20000 Hz.

[0052] Figure 22 (b) shows the longitudinal wavefront of Comparative Example 1 at 20000 Hz.

[0053] Figure 23 (a) shows the longitudinal sound pressure distribution of Comparative Example 1 at 20000 Hz.

[0054] Figure 23 (b) shows the longitudinal sound pressure distribution of Comparative Example 1 at 20000 Hz.

[0055] Figure 24 (a) shows the longitudinal wavefront of the example at 2500 Hz.

[0056] Figure 24 (b) shows the longitudinal wavefront of Comparative Example 2 at 2500 Hz.

[0057] Figure 25 (a) shows the longitudinal sound distribution of the example at 2500 Hz.

[0058] Figure 25 (b) shows the longitudinal sound distribution of Comparative Example 2 at 2500 Hz.

[0059] Figure 26 (a) shows the longitudinal wavefront of the example at 3700 Hz.

[0060] Figure 26 (b) shows the longitudinal wavefront of Comparative Example 2 at 3700 Hz.

[0061] Figure 27 (a) shows the longitudinal sound distribution of the example at 3700 Hz.

[0062] Figure 27 (b) shows the longitudinal sound distribution of Comparative Example 2 at 3700 Hz.

[0063] Figure 28 Shows a perspective view of a conventional diaphragm.

[0064] Figure 29 Shows a perspective view of a conventional diaphragm.

[0065] Figure 30 is a perspective view showing the diaphragm described in JP 2021-125869 A.

[0066] Figure 31 is a perspective view showing the diaphragm described in JP 2021-125869 A. Detailed Embodiments

[0067] Embodiments of the present invention will be described. The numerical values explained below are examples and are not limited to these values. Figure 1 is a perspective view of the diaphragm 1 according to an embodiment of the present invention. Figure 2 is a top view of the diaphragm 1 according to an embodiment of the present invention. In this embodiment, only the conical paper body is defined as the diaphragm 1.

[0068] The diaphragm 1 includes an opening 2, a first reinforcing portion 3, a second reinforcing portion 4, etc. As shown in the figure, when viewed from the top, the length of the diaphragm 1 in one axial direction and the length of the diaphragm 1 in the other axial direction are different in two orthogonal axial directions, and the shape of the diaphragm 1 is a predetermined shape, that is, each side of the longitudinal direction as one axial direction is formed by a curve. Specifically, when viewed from the top, the shape of the diaphragm 1 is an orbital shape (predetermined shape). Here, the "orbital shape" is a shape composed of two parallel lines of equal length and two semi-circles, and is the so-called shape used in a stadium. When viewed from the top, the shape of the diaphragm 1 may be an elliptical shape (predetermined shape). Here, the "elliptical shape" includes a substantially elliptical shape close to the elliptical shape. The "orbital shape" includes a substantially orbital shape close to the orbital shape.

[0069] For example, the length of the longitudinal direction (one axial direction) of the diaphragm 1 is 59.6 mm. In addition, the length of the transverse direction (the other axial direction) of the diaphragm 1 is, for example, 15.1 mm. Therefore, the aspect ratio of the longitudinal direction to the transverse direction of the diaphragm 1 is approximately 4:1. The longitudinal length and the transverse length of the diaphragm are not limited to the above examples. As described above, the longitudinal length and the transverse length of the diaphragm 1 are different from each other. The aspect ratio a:b of the longitudinal direction and the transverse direction is such that when b = 1, a > 1. The aspect ratio of the longitudinal direction and the transverse direction of the diaphragm 1 will be described below.

[0070] The diaphragm 1 has an opening 2 at its center. The shape of the opening 2 is an orbital shape. The shape of the opening 2 is not limited to the orbital shape and may be, for example, an elliptical shape. The diaphragm 1 is formed by a convex curved surface from the opening 2 (center) to the circumference.

[0071] A first reinforcing portion 3 extending longitudinally is provided in the diaphragm 1. The first reinforcing portion 3 is a so-called rib. Two reinforcing portions 3 are provided across the opening 2 in the longitudinal direction. The two reinforcing portions 3 are provided at symmetric positions across the opening 2 (symmetric positions when the transverse direction is used as the axis of symmetry). The two reinforcing portions 3 may be provided at asymmetric positions across the opening 2 (asymmetric positions when the transverse direction is used as the axis of symmetry).

[0072] The width of the reinforcing portion 3 gradually narrows from the center in the longitudinal direction (toward the outer side in the longitudinal direction). That is, when viewed from the top, the shape of the first reinforcing portion 3 is substantially triangular. When viewed from the top, the width of the reinforcing portion 3 may be constant and extend substantially linearly in the longitudinal direction. In addition, it is sufficient that the first reinforcing portion 3 has a portion extending in the longitudinal direction. For example, at the end opposite to the opening 2, a substantially U-shaped rib that clamps the portion extending in the longitudinal direction may be provided.

[0073] In addition, in the diaphragm 1, second reinforcing portions 4 (4a, 4b) are provided adjacent to the first reinforcing portion 3 in the transverse direction. The reinforcing portion 4 is a mesh-like uneven portion. The second reinforcing portion 4 extends radially in the longitudinal direction from the center (from the opening 2 toward the outer side in the longitudinal direction). Two second reinforcing portions 4 are provided across the first reinforcing portion 3 in the transverse direction. The two second reinforcing portions 4a and 4b across the first reinforcing portion 3 have different mesh shapes from each other. Two sets of the two second reinforcing portions 4a and 4b are provided across the opening 2 (the center in the longitudinal direction). The two second reinforcing portions 4a are point-symmetric with respect to the center of the diaphragm 1. Similarly, the two second reinforcing portions 4b are point-symmetric with respect to the center of the diaphragm 1. The second reinforcing portion 4 does not overlap with the first reinforcing portion 3. That is, the first reinforcing portion 3 and the second reinforcing portion 4 are arranged independently of each other.

[0074] For example, the width of the convex portion in the second reinforcing portion 4 is 0.3 mm. For example, the height of the convex portion is 0.5 mm. The width and height are not limited to these values.

[0075] The second reinforcing portion 4 imitates the wings of an insect. The uneven portion of the wings of an insect can be imitated based on data obtained by measuring the shape of the actual wing veins of an insect. For example, the crossing positions between the wing veins are two-dimensionally specified from a photograph of an insect and converted into data. These crossing points are connected to each other, so that an uneven portion imitating the actual wing veins can be reproduced. In actual wing veins, the distance between the wing vein crossing points varies. The wing veins form such an uneven portion that many polygons (mainly triangles, rectangles, or pentagons) of various sizes and shapes are connected to each other. The uneven portion of the wing veins realizes a structure having the strength and lightness required for an insect to fly.

[0076] Note that the dimensions of the concave and convex portions for the diaphragm are not limited to the dimensions that match the actual insect wing vein dimensions, and in fact, these dimensions are magnified several times during use. Since the actual insect wing area is small, during use, the dimensions of the relative ratio of the dimensions maintaining the concave and convex portions are appropriately enlarged. In addition, the concave and convex portions formed by the insect wing veins can be utilized, such that the vein portions are thick convex portions, and the thin film portions surrounded by the wing veins are thin concave portions, and it is not necessary to precisely imitate the thick dimensions.

[0077] The concave and convex portions are formed such that a plurality of identical wing vein shapes with a predetermined area are repeatedly arranged. For example, the concave and convex portions are formed based on data obtained by measuring the shape of the actual dragonfly wing veins. The concave and convex portions are not limited to dragonflies, and the wings of other insects, such as cicadas, butterflies, beetles, and ladybugs, can be imitated.

[0078] In addition, considering that the concave and convex portions of the insect wing are similar to the Voronoi diagram, the concave and convex portions imitating the insect wing veins can be generated from the data of the generated Voronoi diagram. The Voronoi diagram is a diagram obtained in such a way that a number of points (parent points) are taken on a plane and connected by lines to draw a graph, the perpendicular bisectors of the sides of the formed triangles are connected to draw a graph, and the initially generated lines are removed. The Voronoi diagram can also be regarded as a diagram obtained in such a way that the parent points arranged on the plane are divided according to the proximity to other parent points. Therefore, by using the perpendicular bisectors in the Voronoi diagram, the concave and convex portions imitating the insect wing veins can be drawn. The concave and convex portions can be formed based on the data of the Voronoi diagram imitating the insect wing veins.

[0079] In the wing veins forming the concave and convex portions of the insect wing, body fluid only flows when extending from the wing. After the wing is formed, the wing veins in which the body fluid flows become dry and empty. This helps the structure to have the required strength and lightness of the wing. Therefore, in the diaphragm 1 having concave and convex portions imitating the insect wing according to the present invention, a hollow space imitating the insect wing veins can be formed inside.

[0080] For example, in the concave and convex portions imitating the insect wing, the density of the diaphragm material in the thick convex portions can be lower than that of the thin concave portions. In addition, in the diaphragm formed by bonding the front material and the back material, the diaphragm can be formed such that the thin concave portions are bonded to each other, and a hollow space in which the front material and the back material do not bond to each other is provided inside the thick convex portions.

[0081] The "insect wing" is the so-called insect wing, which is an elongated external frame on the back and is composed of chitin. The "wing vein" refers to the thick chitin tendon that extends onto the insect wing like a leaf vein and is used to support the wing that unfolds in a membranous form.

[0082] Note that the reinforcing portion 4 may not imitate an insect wing. For example, the second reinforcing portion 4 has a plurality of polygonal convex portions and a plurality of polygonal concave portions, and these polygonal concave portions are formed inside the convex portions by the convex portions. Among the plurality of convex portions, one side of adjacent convex portions may be a portion forming two polygons. Other shapes of the second reinforcing portion 4 will be described below.

[0083] Figure 3 is a perspective view showing the diaphragm 1 according to this embodiment. Figure 4 is a perspective view showing the speaker unit 101 according to this embodiment. The speaker unit 101 includes a diaphragm 1, a voice coil, a dust cap 6, a surround 5, a frame 7, a magnetic circuit, etc. The voice coil is connected to the opening 2 of the diaphragm 1. The voice coil has a bobbin and a coil wound around the bobbin. The dust cap 6 is connected to the voice coil. Specifically, the dust cap 6 is attached to the end of the bobbin by an adhesive, for example. The surround 5 is connected to the outer peripheral portion of the diaphragm and supports the diaphragm 1 so as to vibrate. For example, the material of the surround 5 is NBR hardness 60.

[0084] The frame 7 is connected to the outer peripheral portion of the surround 5. The magnetic circuit is fixed to the frame 7. The magnetic circuit has a magnetic gap in which the coil of the voice coil is arranged. The magnetic circuit is composed of a top plate, a magnetic pole, and a magnet. The top plate is annular and fixed to the frame 7. The magnetic pole is cylindrical and has a central magnetic pole and a flat bottom plate. The central magnetic pole is inserted into a circular opening formed in the center of the top plate and has a flat bottom plate. The magnet is annular.

[0085] The characteristics of the diaphragm 1 according to this embodiment will be compared with other examples below. Figure 5 is a model diagram (Comparative Example 1) of a diaphragm in which only the first reinforcing portion 3 (linear-shaped reinforcing rib) of the diaphragm 1 is provided and the second reinforcing portion 4 of the diaphragm 1 is not provided. Figure 6 is a model diagram (Comparative Example 2) of a diaphragm in which the first reinforcing portion 3 of the diaphragm 1 is not provided in a wide range of the diaphragm 1 and the second reinforcing portion 4 (concavo-convex-shaped wing vein pattern rib) is provided. Figure 7 is a model diagram showing the diaphragm similar to that shown in Figures 27 to 3 2 of JP 2021-125869 A (Comparative Example 3), in which the concavo-convex shape (concavo-convex wing vein pattern rib) of the second reinforcing portion 4 of the diaphragm 1 is provided on a convex reinforcing portion (raised rib). Figure 8 is a model diagram showing the diaphragm 1 according to the embodiment (Example). Each model is made by setting a voice coil and a damper of a predetermined shape to Figures 5 to 8 each of the diaphragms shown. The respective results of acoustic analysis by the boundary element method (BEM) will be described below. In Comparative Examples 1 to 3 and the Example, calculations are performed under the same analysis conditions (driving force: 1 N, microphone distance: 1 m).

[0086] Figure 9 It is a graph showing the frequency characteristics of the example and Comparative Example 1. Figure 10 (a) of is a diagram showing the movement of the model of the example at 2300 Hz. Figure 10 (b) of is a diagram showing the movement of the model of Comparative Example 1 at 2300 Hz. In Comparative Example 1, due to insufficient rigidity around the linear-shaped reinforcing rib, the edge jitter is large and there is a peak drop. In addition, in this example, since the second reinforcing portion (concavo-convex vein pattern rib) is arranged around the first reinforcing portion (linear-shaped reinforcing rib), there is no edge jitter and the peak drop is suppressed. Figure 11 (a) of is a diagram showing the movement of the model of the example at 3200 Hz. Figure 11 (b) of is a diagram showing the movement of the model of Comparative Example 1 at 3200 Hz. In Comparative Example 1, an anti-phase mode in the longitudinal direction is seen and a large drop appears. In addition, in the example, such a drop does not occur. Figure 12 (a) of is a diagram showing the movement of the model of the example at 9200 Hz. Figure 12 (b) of is a diagram showing the movement of the model of Comparative Example 1 at 9200 Hz. In the comparative example, jitter in the longitudinal direction is seen. In addition, the overall stiffness increases, the resonance peak is effectively dispersed by the second reinforcing portion (concavo-convex vein pattern rib), and several peak drops appear.

[0087] Figure 13 It is a graph showing the frequency characteristics of the example, Comparative Example 2, and Comparative Example 3. Figure 14 (a) of is a diagram showing the movement of the model of the example at 2500 Hz. Figure 14 (b) of is a diagram showing the movement of the model of Comparative Example 2 at 2500 Hz. In a thin and long shape with a large aspect ratio such as an aspect ratio of about 4:1, the degree of increasing stiffness only in the longitudinal direction by the concavo-convex vein pattern rib as in Comparative Example 2 is limited, edge jitter can be seen and a large drop appears. Similarly, in Comparative Example 2, since the vein pattern rib is arranged on the raised rib, the effect of the raised rib is weakened. In addition, in the example, such a phenomenon is not seen. Figure 15 (a) of is a diagram showing the movement of the model of the example at 3700 Hz. Figure 15 (b) of is a diagram showing the movement of the model of Comparative Example 2 at 3700 Hz. In Comparative Example 2, due to the jitter of the diaphragm, the edge deformation is large, resulting in a resonance peak. In addition, in the example, such a phenomenon is not seen.

[0088] Figure 16 (a) of is a diagram showing the longitudinal wavefront of the example at 2300 Hz. Figure 16(b) is a diagram showing the longitudinal wavefront of Comparative Example 1 at 2300 Hz. Figure 17 (a) is a diagram showing the longitudinal sound pressure distribution of the Example at 2300 Hz. Figure 17 (b) is a diagram showing the longitudinal sound pressure distribution of Comparative Example 1 at 2300 Hz. In Comparative Example 1, although a large deformation at the edge was observed, there was no interference of the wavefront.

[0089] Figure 18 (a) is a diagram showing the longitudinal wavefront of the Example at 3200 Hz. Figure 18 (b) is a diagram showing the longitudinal wavefront of Comparative Example 1 at 3200 Hz. Figure 19 (a) is a diagram showing the longitudinal sound pressure distribution of the Example at 3200 Hz. Figure 19 (b) is a diagram showing the longitudinal sound pressure distribution of Comparative Example 1 at 3200 Hz. In Comparative Example 1, the perturbation of the wavefront occurred in the longitudinal antiphase mode. In addition, no interference of the wavefront was observed in the Example.

[0090] Figure 20 (a) is a diagram showing the longitudinal wavefront of the Example at 9200 Hz. Figure 20 (b) is a diagram showing the longitudinal wavefront of Comparative Example 1 at 9200 Hz. Figure 21 (a) is a diagram showing the longitudinal sound pressure distribution of the Example at 9200 Hz. Figure 21 (b) is a diagram showing the longitudinal sound pressure distribution of Comparative Example 1 at 9200 Hz. In Comparative Example 1, since longitudinal splitting resonance occurred, the wavefront was greatly disturbed. In addition, in the Example, there was no large interference and the wavefront close to a sphere was maintained.

[0091] Figure 22 (a) is a diagram showing the longitudinal wavefront of the Example at 20000 Hz. Figure 22 (b) is a diagram showing the longitudinal wavefront of Comparative Example 1 at 20000 Hz. Figure 23 (a) is a diagram showing the longitudinal sound pressure distribution of Comparative Example 1 at 20000 Hz. Figure 23 (b) is a diagram showing the longitudinal sound pressure distribution of Comparative Example 1 at 20000 Hz. In Comparative Example 1, the wavefront was greatly disturbed by splitting resonance. In addition, in the Example, since the first reinforcing portion 3 and the second reinforcing portion 4 were used simultaneously, the wavefront close to a sphere was maintained.

[0092] Figure 24 (a) is a diagram showing the longitudinal wavefront of the Example at 2500 Hz. Figure 24(b) is a diagram showing the longitudinal wavefront of Comparative Example 2 at 2500 Hz. Figure 25 (a) is a diagram showing the longitudinal sound distribution of the Example at 2500 Hz. Figure 25 (b) is a diagram showing the longitudinal sound distribution of Comparative Example 2 at 2500 Hz. In Comparative Example 2, wavefront perturbation occurred due to insufficient rigidity in the longitudinal direction. In the Example, there was no significant interference and a spherical wave was maintained.

[0093] Figure 26 (a) is a diagram showing the longitudinal wavefront of the Example at 3700 Hz. Figure 26 (b) is a diagram showing the longitudinal wavefront of Comparative Example 2 at 3700 Hz. Figure 27 (a) is a diagram showing the longitudinal sound distribution of the Example at 3700 Hz. Figure 27 (b) is a diagram showing the longitudinal sound distribution of Comparative Example 2 at 3700 Hz. In Comparative Example 2, the wavefront was slightly disturbed due to the jitter of the edge in the longitudinal direction. In addition, in the Example, there was no significant interference to the wavefront.

[0094] As described above, in the embodiment, a first reinforcing portion 3 extending in the longitudinal direction and a second reinforcing portion 4 adjacent to the first reinforcing portion 3 and having a mesh-shaped uneven portion are provided. Therefore, (1) the jitter of the edge 5 provided in the diaphragm 1 is suppressed. In addition, (2) the first reinforcing portion 3 increases the overall stiffness, and the second reinforcing portion 4 effectively disperses the resonance peaks. According to this embodiment, the peak drop in the diaphragm 1 is suppressed by (1) or (2).

[0095] In addition, the second reinforcing portion 4 has a frame extending radially from the center in the longitudinal direction and serves to supplement the first reinforcing portion 3. Therefore, the splitting resonance in the high frequency is reduced.

[0096] Here, preferably, the aspect ratio of the longitudinal length to the transverse length of the diaphragm 1 is not less than 2:1. More preferably, the aspect ratio is not less than 3:1. This is because in a diaphragm with a large aspect ratio, the longitudinal stiffness is insufficient, but the effects of the first reinforcing portion 3 and the second reinforcing portion 4 are more effective in such a diaphragm.

[0097] In addition, for example, the grid of the uneven portion of the second reinforcing portion 4 can be a lattice (a state where multiple vertical lines and multiple horizontal lines intersect). The grid of the uneven portion of the second reinforcing portion 4 can be, for example, a regular shape having a plurality of rectangular convex portions of the same shape. If the grid of the uneven portion of the second reinforcing portion 4 is a shape without the regularity like the wing vein pattern described in this embodiment, the resonance dispersion effect of the second reinforcing portion 4 is large.

[0098] The embodiments of the present invention have been described above, but the applicable modes of the present invention are not limited to the above embodiments and can be appropriately changed without departing from the scope of the present invention.

[0099] The present invention can be applied to a diaphragm and a speaker unit including the diaphragm.

Claims

1. A diaphragm, in which, when viewed from the top, the length in one axial direction and the length in the other axial direction are different in two orthogonal axial directions, and the diaphragm has a predetermined shape, the predetermined shape being formed by curves on both sides in the longitudinal direction as the one axial direction. The diaphragm includes: A first reinforcing portion that extends along the longitudinal direction; And A second reinforcing portion that is disposed adjacent to the first reinforcing portion in the transverse direction and is a reticulated concave-convex portion.

2. The diaphragm according to claim 1, Among them, The second reinforcing portion mimics the wings of an insect.

3. The diaphragm according to claim 2, Among them, The second reinforcing portion is based on data obtained by measuring the actual shape of the wing veins of the insect or data of a Voronoi diagram that mimics the wing veins of the insect.

4. The diaphragm according to claim 1, Among them, The second reinforcing portion has: A plurality of polygonal convex portions, and A plurality of polygonal concave portions that are formed inside these convex portions by the convex portions, and Among the plurality of polygonal convex portions, one side of adjacent convex portions is a portion where two polygons are formed.

5. The diaphragm according to claim 1, Among them, The second reinforcing portion extends radially from the center along the longitudinal direction.

6. The diaphragm according to claim 1, Among them, Two of the second reinforcing portions are disposed across the first reinforcing portion in the transverse direction.

7. The diaphragm according to claim 6, Among them, The mesh shapes in the two second reinforcing portions are different from each other.

8. The diaphragm according to claim 6, Among them, The two sets of the first reinforcing portion and the two second reinforcing portions are arranged to straddle the center in the longitudinal direction.

9. The diaphragm according to claim 8, Among them, The two second reinforcing portions straddling the center in the longitudinal direction are symmetric with respect to the center point.

10. The diaphragm according to claim 1, Among them, The width of the first reinforcing portion gradually narrows along the longitudinal direction from the center in the longitudinal direction.

11. The diaphragm according to claim 1, Among them, The aspect ratio of the length in the longitudinal direction to the length in the transverse direction is not less than 2:

1.

12. A speaker unit, the speaker unit includes: A diaphragm; A voice coil that is connected to the opening of the diaphragm; A dust cap that is coupled to the voice coil; An edge that is coupled to the outer periphery of the diaphragm; A frame to which the outer periphery of the edge is fixed; And A magnetic circuit that has a magnetic gap, the coil of the voice coil is disposed in the magnetic gap and the magnetic circuit is fixed to the frame, Wherein, when viewed from the top, the diaphragm has a length in one axial direction and a length in the other axial direction that are different in two orthogonal axial directions, and the diaphragm has a predetermined shape, the predetermined shape being formed by curves on both sides in the longitudinal direction as the one axial direction. The diaphragm includes: A first reinforcing portion that extends along the longitudinal direction; and A second reinforcing portion that is disposed adjacent to the first reinforcing portion in the transverse direction and has a reticulated concave-convex portion.

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