JP2000078686A - Diaphragm for electroacoustic transducer and electroacoustic transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diaphragm for an electroacoustic transducer that is formed nearly spherical, obtains high amplitude and a large output sound. SOLUTION: The transducer is constituted by combining two hemispheres, each sphere has a torus base member, a diaphragm 4 of almost a semishere having a conductive layer and hemispherical inner and outer electrode plates respectively placed to an inner circumferential side and an outer circumferential side of the diaphragm 4 with an interval, the diaphragm 4 has a combination of triangles each consisting of line segments drawn from centers of gravity o1, o2 of a pentagon and a hexagon to apexes t1, t2 and being folded in V-shape by perpendiculars v1, v2 drawn from the centers of gravity to each side, the centers of gravity o1, o2 of each polygon are placed at positions projecting in a direction where the radius is increasing and feet of the perpendiculars v1, v2 drawn to each side are folded in a direction where the radius is decreasing and the feet of both the perpendiculars v1, v2 drawn to a common side of adjacent polygons are consecutive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a diaphragm of an electroacoustic transducer having a spherical shape and an electroacoustic transducer.

[0002]

2. Description of the Related Art As a speaker (electroacoustic transducer) having a spherical shape, a piezoelectric speaker shown in FIG. 16 is conventionally known.

In FIG. 16, the speaker has two hemispheres 50, and the two hemispheres 50 are combined with their end faces joined to each other. Each hemisphere 50 is PZT
Hemispherical diaphragm 51 made of (piezoelectric ceramic)
And a concentric hemispherical metal frame 52 arranged at a constant interval on the outer peripheral side of the diaphragm 51, and a rubber pad 53 arranged between the diaphragm 51 and the metal frame 52. The sound absorbing material 5 is provided in the spherical internal space of the diaphragm 51.
4 are filled. When an audio signal is input between the inner surface and the outer surface of the diaphragm 51, the diaphragm 51 vibrates in the radial direction in accordance with the voltage of the audio signal, and a sound is output.

[0004]

However, in the conventional speaker (electrostatic electroacoustic transducer), the diaphragm 5
1 uses a piezoelectric ceramic, so that the amplitude of the vibration is small, and as a result, there is a problem that the output sound is small.

Accordingly, the present invention has been made to solve the above-mentioned problems, and has a substantially spherical shape, a large amplitude, and a diaphragm of an electro-acoustic transducer and a large output sound. It is intended to provide a converter.

[0006]

According to a first aspect of the present invention, there is provided a vibration plate having a conductive layer and having a substantially spherical shape, and a space provided between at least one of an inner peripheral side and an outer peripheral side of the diaphragm. An electroacoustic transducer comprising: an electrode plate having a spherical shape disposed therein; and an n-gon (n: an integer of 4 or more) and (n + 1)
Each triangle consisting of a line segment drawn from the center of gravity of the polygon to each vertex is a combination of shapes that are folded into a V shape by a perpendicular drawn from the center of gravity to each side, and the center of gravity of each polygon has a large radius. It is arranged at a position protruding in the direction in which the legs of the perpendicular drawn on each side are folded in the direction of decreasing radius,
The diaphragm of the electro-acoustic transducer is characterized in that both perpendicular legs drawn on a common side of an adjacent polygon are configured to be continuous.

According to a second aspect of the present invention, there is provided the diaphragm of the electroacoustic transducer according to the first aspect, wherein the diaphragm is formed into a substantially spherical shape by joining a plurality of divided parts.

According to a third aspect of the present invention, each triangle consisting of a line segment drawn from the barycenter of the n-gon (n: an integer of 4 or more) and the (n + 1) -gon to each vertex is drawn from the barycenter to each side. A combination of shapes that are folded into a V-shape by perpendiculars, where the center of gravity of each polygon is placed at a position protruding in the direction of increasing radius, and the leg of the perpendicular drawn on each side is folded in the direction of decreasing radius. And a diaphragm having both perpendicular lines drawn on a common side of an adjacent polygon being continuous, and having an opening provided in a part thereof; A sound output unit that is fixed and outputs sound to the internal space of the diaphragm through the opening.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a sectional view of a spherical speaker (electrostatic electroacoustic transducer) showing a first embodiment of the present invention.
(B) is an enlarged sectional view of a diaphragm, FIG. 2 is a sectional view of a hemisphere,
3A is a front view of the outer electrode plate, FIG. 3B is a bottom view of the outer electrode plate, FIG. 4 is a perspective view of the diaphragm, FIG. 5 is a diagram illustrating the configuration of the diaphragm, and FIG. It is a figure showing a vibration state.

As shown in FIGS. 1 and 2, a spherical speaker S
Is composed of two hemispheres 1 and these two hemispheres 1 are assembled together. Each hemisphere 1 has a flat annular base member 2, a hemispherical inner electrode plate 3, a hemispherical diaphragm 4, a hemispherical outer electrode plate 5, and a hemispherical cover 6.
And

The base member 2 is made of a resin such as polycarbonate. A positioning pin 2b is provided on one surface of the base member 2 so as to project 180 degrees from the other, and the other surface of the base member 2 is joined to another hemisphere. It is configured as a joint surface 2a. The base member 2 is provided with screw insertion holes (not shown) at appropriate intervals.

The inner electrode plate 3 is made of a metal obtained by plating chrome on copper, brass or the like, and has a hemispherical hemispherical portion 3a and an annular shape extending around the outer periphery of the hemispherical portion 3a and extending in the radial direction. And a flange portion 3b. Hemispherical part 3
Although not shown, a is provided with a plurality of holes, and the number is preferably equal to or less than the number of holes 5c of the outer electrode plate 5 described below. The flange 3b is provided with a positioning hole or a notch for positioning (not particularly denoted by a reference numeral) and a screw insertion hole or notch (not shown), and the positioning pin 2b of the base member 2 is provided in the positioning hole or the notch for positioning. Inserted or engaged. Thus, the inner electrode 3 is positioned and arranged on the base member 2 so that the center of the hemispherical portion 3a coincides with the center of the base member 2.

The vibrating plate 4 is slightly larger than the inner electrode plate 3, but is also substantially hemispherical hemispherical portion 4 a and a circle extending on the outer periphery of the hemispherical portion 4 a and extending in the radial direction. And an annular flange 4b. Similarly, although not shown, a positioning hole or a notch for positioning (not particularly denoted by a reference numeral) and a screw insertion hole or a notch (not shown) are provided in the flange portion 4b. The positioning pin 2 b of the member 2 is inserted or engaged, but is disposed on the flange 3 b of the inner electrode plate 3 via an annular spacer 7. The spacer 7 is appropriately formed of one or more members depending on the interval to be secured.

The hemispherical portion 4a of the diaphragm 4 has a shape substantially as shown in FIG. 4 when the two are joined. That is, as shown in FIG. 5, a dotted pentagon (n-gon, where n is an integer of 4 or more) and a dotted hexagon (n + 1)
Each of the triangles formed by the line segments l ₁ and l ₂ drawn from the centers of gravity O ₁ and O ₂ of the (corner) to the respective vertices t ₁ and t ₂ is transformed from the centers of gravity O ₁ and O ₂ to the respective sides m ₁ and m ₂ . It is a combination of shapes folded in a V shape by drawn perpendiculars v ₁ and v ₂ , and the centers of gravity O ₁ ,
O ₂ is arranged at a position protruding in the direction in which the radius increases, and the legs of the perpendiculars v ₁ , v ₂ drawn on each side m ₁ , m ₂ are bent in the direction in which the radius decreases, and are adjacent to each other It is configured such that the legs of both perpendiculars v ₁ and v ₂ drawn on the common sides m ₁ and m ₂ of the polygon are continuous. This structure can be easily displaced around the legs at the perpendiculars v ₁ and v ₂ when an external force acts in the radial direction. The point of intersection N between the legs v ₁ and v ₂ is the point of maximum amplitude.

The sectional configuration of the diaphragm 4 is shown in FIG.
As shown in FIG. 2, a resin base layer 20 formed of a resin that can expand and contract in the radial direction, a strength reinforcing layer 22 disposed on one surface of the resin base layer 20, and a resin reinforcing layer 22 on one surface of the strength reinforcing layer 22. It is configured by laminating a conductive layer 21 formed by depositing a conductive metal. In this embodiment, the strength reinforcing layer 22 is made of a foamed polypropylene (foamed material) which is a porous layer. However, the strength reinforcing layer 22 may be a member capable of reinforcing the strength without hindering the expansion and contraction of the resin base layer 20 in the radial direction. Good.
The diaphragm 4 is reinforced with the strength reinforcing layer 22. Those having material properties as shown in Table 1 below are preferable.

[0017]

[Table 1] The diaphragm 4 is formed by laminating a resin base layer 20 and a strength reinforcing layer 22 and then depositing a conductive metal to form a conductive layer 21. When the conductive layer 21 is formed, the strength of the resin base layer 20 is reinforced by the strength reinforcing layer 22, so that the resin base layer 20 can maintain a hemispherical shape. It becomes possible.

As shown in FIGS. 3 (a) and 3 (b), the outer electrode plate 5 is slightly larger than the vibrating plate 4, but is made of the same material as the inner electrode plate 3 and similarly has a hemispherical shape. It is composed of a hemispherical portion 5a and an annular flange portion 5b which is provided on the outer periphery of the hemispherical portion 5a and extends in the radial direction. The hemispherical portion 5a is provided with a plurality of holes 5c for emitting sound waves. Although not shown, a positioning hole 5 is formed in the flange 5b.
d and a screw insertion hole 5e are provided, and the positioning pin 2b of the base member 2 is inserted into the positioning hole 5d.
Arranged on the flange 4 b of the diaphragm 4 via an annular spacer 8. The spacer 8 is appropriately formed of one or more members depending on the interval to be secured.

The cover 6 is made of, for example, a urethane resin having a good air flow. The cover 6 is larger than the outer electrode plate 5 and has a hemispherical hemispherical portion 6a and an outer periphery of the hemispherical portion 6a. And an annular flange portion 6b extending from the ring. A positioning recess 6c is formed on the lower surface of the flange 6b, and the positioning pin 2b of the base member 2 is inserted into the positioning recess 6c. The flange 6b of the cover 6 is provided with a screw insertion hole (not shown).

The inner electrode plate 3, the vibrating plate 4, the outer electrode plate 5, and the cover 6 have respective positioning holes and positioning concave portions 6c positioned with the positioning pins 2b of the base member 2, and the respective hemispherical portions 3a to 6a are identical. They are arranged concentrically about the center. Also, because they are arranged concentrically,
Each space between the inner electrode plate 3, the vibration plate 4, the outer electrode plate 5, and each of the hemispherical portions 3a to 6a of the cover 6 is uniformly formed at any position.

Two hemispheres 1 configured as described above are provided, and the two hemispheres 1 are fixed by screwing using screw insertion holes in a state where the joining surfaces 2a are joined to each other. The spherical speaker S shown in FIG. 1A is configured.

In the above configuration, each hemisphere 1 has 4000
When a DC bias voltage of V or more (for example, 4300 V) is applied, capacitors are formed between the diaphragm 4 of each hemisphere 1 and the inner electrode plate 3 and the outer electrode plate 5 by this DC bias voltage, and the electrostatic effect is generated. The situation in which is caused is configured. In this state, when a driving current, which is an audio signal, is supplied to each hemisphere 1, the diaphragm 4 of each hemisphere 1 receives an external force in the radial direction in synchronization with the driving current, thereby causing the following respiration. Do exercise.

That is, in FIG. 5 and FIG. 6, each polygon is a triangle composed of l ₁ and m ₁ and a triangle composed of l ₂ and m _{2 with the} centers of gravity O ₁ and O ₂ as fixed points. It vibrates in the radial direction (the direction of the arrow in FIG. 6) around the feet of the perpendiculars v ₁ and v ₂ . The intersection N of the legs of the perpendiculars v ₁ and v ₂ is the maximum amplitude point. The fluctuation in the radial direction is similar to respiratory motion as a whole, and a sound source (spherical sound field) close to a respiratory sphere is realized. The amplitude is much larger than that of the piezoelectric ceramic, and a large sound output can be obtained. Further, since the respiratory motion does not depend only on the material properties of the diaphragm 4, it can be said that a material having a large Young's modulus can be used as the diaphragm 4.

A plurality of holes 5c are formed in the hemispherical portion 5a of the outer electrode plate 5, and a sound wave is radiated through the holes 5c. The inner electrode plate 3 also has a plurality of holes (not shown). ) Is formed, the air pressure on the inner surface side of the diaphragm 4 is reduced, whereby the bass reproduction limit frequency can be lowered.

Furthermore, the spatial distance between the outer peripheral end surface of the flange 4b of the diaphragm 4 and the outer peripheral end surface of the flange 3b of the inner electrode plate 3,
The spatial distance between the outer peripheral end surface of the flange 4b of the diaphragm 4 and the outer peripheral end surface of the flange 5b of the outer electrode plate 5 is 4 m each.
m, the discharge does not occur due to the above-described DC bias voltage of, for example, 4300V.

On the other hand, it is possible to output a sound even with only the hemisphere 1, and in this case, a hemispheric wave sound field can be realized.

Further, since the diaphragm 4 is strong in strength as described above, there is no possibility that the diaphragm 4 will be damaged by an impulse input.

FIG. 7 is a sectional view showing a modification of the sectional structure of the diaphragm 4. In FIG. 7, as compared with the above-described one in FIG. 1B, in this modification, in addition to the configuration in FIG. 1B, a resin base layer 23 is further provided on the lower surface of the strength reinforcing layer 22. . Since other configurations are the same as those in FIG. 1B, the same reference numerals are given to the drawings, and the description thereof will be omitted. In this modified example, since the resin base layer 23 has two layers, the strength is further increased, and the possibility that the diaphragm 4 is damaged by an impulse input is further reduced.

As described above, according to the first embodiment, a plurality of divided parts, that is, two diaphragms 4 are joined to form a substantially spherical shape. It is easy to make a spherical shape and its mold. The number of divisions may be three, four, or more. According to the above-described embodiment, the substantially hemispherical diaphragm 4 having the flange portion 4b is connected, but the divided components are adhered to each other with an adhesive or the like to form a diaphragm having no fixed flange portion 4b. if,
Further, a sound source (spherical sound field) close to a complete respiratory sphere can be realized.

FIG. 8 is a schematic sectional view of a spherical speaker (electroacoustic transducer) showing a second embodiment of the present invention. In FIG. 8, the spherical speaker S includes a spherical diaphragm 30 which is a substantially spherical diaphragm, and an audio output unit 31 fixed to the spherical diaphragm 30. The spherical diaphragm 30
Compared to the diaphragm 4 of the first embodiment, the difference is that there is no flange portion and that a part of the diaphragm 4 has an opening 30a. However, since the other configuration is the same, the same configuration Will be omitted to avoid redundant description, and only different components will be described.

That is, the opening 30a is formed by removing a part of a pentagon (n-gon, where n is an integer of 4 or more) or a hexagon constituting the spherical diaphragm 30. The sound output section 31 has an opening (particularly, no reference numeral) of the diaphragm 31a adhered to a periphery of the opening 30a, and an internal space of the spherical diaphragm 30 via the opening 30a. It is configured to output audio to the device. Also, audio output unit 3
A hole (not shown) is provided in the vicinity of the center axis of No. 1.

A hole may be provided in the spherical diaphragm 30 instead of, or in combination with, the hole of the audio output section 31.

In the above configuration, when the sound output unit 31 is driven and the diaphragm 31a vibrates (piston vibration),
Due to this vibration, the spherical diaphragm 30 receives an external force in the radial direction, vibrates in the direction of the arrow in FIG. 8, and performs a respiratory movement similar to that of the first embodiment. In other words, the piston vibration of the diaphragm 31a of the audio output unit 31 is converted by the spherical diaphragm 30 into a sound similar to a respiratory movement, and natural bass reproduction without a sound source feeling is realized.

Here, since the frequency components higher than a certain frequency reproduced by the audio output unit 31 are cut by the acoustic filter function of the pseudo respiratory sphere (spherical diaphragm 30), the bass reproduction is made easier. However, since this function has properties such as depending on the diameter of the pseudo respiratory sphere (spherical diaphragm 30), more effective reproduction can be performed by limiting the band of the input of the audio output unit 31 in advance. it is conceivable that.

Further, as in the first embodiment, the amplitude is much larger than that of the piezoelectric ceramic, and a large sound output can be obtained. Further, since the respiratory motion does not depend only on the material properties of the spherical diaphragm 30, it can be said that a material having a large Young's modulus can be used as the spherical diaphragm 30.

Further, since a hole (not shown) is provided in the vicinity of the central axis of the sound output section 31, the spherical diaphragm 30
Imbalance such as vertical asymmetry and temperature difference of the spherical diaphragm are adjusted. Since this hole does not actively function as an air hole, a hole having a diameter of about 10 mm is sufficient.

FIG. 9 is a partially cutaway front view of a spherical speaker (electro-acoustic transducer) showing a modification of the second embodiment. 9 differs from the second embodiment in that a cabinet 32 is provided on the back side of the audio output unit 31, and the cabinet 32 seals the back side of the audio output unit 31.

In this modification, since the influence of the negative phase component outputted from the back side of the audio output unit 31 can be eliminated, more ideal reproduction is possible.

Next, according to the first and second embodiments,
Diaphragm 4, whose basic form is a combination of a pentagon and a hexagon
A method for forming the spherical diaphragm 30 will be described.

First, how to make a basic shape will be described. still,
Here, the basic shape refers to a case where the pentagonal and hexagonal surfaces are still flat.

FIG. 10 is a sectional view of the basic shape of the diaphragm 4 or the spherical diaphragm 30, for example, passing through the equator q (shown in FIG. 12).
FIG. 11 is a development view of a pentagon and a hexagon relating to one round. In FIGS. 10 and 11, when the length of one side of the pentagon or the hexagon is L, and the radius of a circumscribed sphere (indicated by a dotted line in FIG. 10) of the basic shape of the diaphragm 4 or the spherical diaphragm 30 is r. , The following equation holds. That is, 8a ² b ² cL ² −
4 (a ⁴ + b ⁴ ) L ⁴ -4c (a ² + b ² ) L ^3- (c ² -4
a ² -4b ²⁾ equation of L ² + 2cL-1 = 0 is established. Here, a = cot30 ° / 2r, b = cot18 ° / 4
r and c = 1 / 2r.

In the above equation, when the value of L when the value of the radius r is 50 is obtained, L = 20.46.
A basic shape of a pentagon and a hexagon having this value as one side is created.

Next, how to form the pentagonal and hexagonal bent surfaces will be described. FIG. 12 is a developed view showing a pentagon and a hexagon related to one round passing through the equator q and showing the position of a polygonal line f. FIG. 13 is a diagram showing the basic shape of the diaphragm 4 or the spherical diaphragm 30, for example, the equator Cross-section (indicated by the thick line) passing through
FIG. 14 is a cross-sectional view showing a cross section (indicated by a thin line) in a state where a bent surface is formed in a polygon and a hexagon. FIG. 14 is a diagram showing a hexagon shown by oblique lines in FIG.
FIG. 15 is a diagram showing a tetrahedron formed by the ridge lines in FIG. 14 and coordinates for determining the shape of the tetrahedron.

In FIGS. 12 to 15, when the hexagon is adjacent to the hexagon, that is, the coordinates of the tetrahedron are as shown in FIG. 14, assuming that the length of one side of the hexagon is L = 20.46. Since h ² = a ² + b ² , h = 3.265. Edge s located at the bottom of each shape (shown in FIG. 15)
Is a = 3.05 and b = 1.164 from the condition that one line segment is shared with that of the adjacent shape. Therefore, if the vertex coordinates of the tetrahedron are (0, 0, 0), then 3
The coordinates of the point are 1 (0, 0, 49.69), 2 (17.7
2, 10.23, 46.42), 3 (16.55, 0,
43.37).

The coordinates of the location where the hexagon and the pentagon are adjacent, that is, the coordinates of the tetrahedron, are h = 2.58, where L = 20.46 is the length of one side of the hexagon or pentagon. The ridge line at the bottom of each shape is 1
From the condition that the line segments are shared, a = 2.41, b
= 0.92. Therefore, the coordinates of the vertices of the tetrahedron are (0,
0, 0), the coordinates of the three points are 1 (0, 0, 49.
69), 2 (17.72, 10.23, 46.42),
3 (16.79, 0, 44.01).

The pentagon and the pentagon are adjacent to each other, that is, the coordinates of the tetrahedron are such that the length of one side of the pentagon is L = 20.
Assuming that 46, h = 2.58. The ridge line located at the bottom of each shape shares one line segment with that of the adjacent shape, so that a = 2.48 and b = 0.73
Becomes Therefore, if the vertex coordinates of the tetrahedron are (0, 0, 0), the coordinates of the three points are 1 (0, 0, 49.69), 2
(14.08, 10.23, 47.65), 3 (13.
35, 0, 45.18). If the tetrahedrons created as described above are three-dimensionally combined, a desired diaphragm 4 or spherical diaphragm 30 can be produced.

In actual production, it is conceivable that the shape obtained by dividing this shape into four parts is formed by a mold and joined to each other, and the joint is produced. As a method, a combination of a hexagon and a pentagon is considered. There are two cases: a case in which the basic shape is a four-divided shape based on the basic shape, and a case in which a spherical shape obtained by dividing the spherical shape into four is used.

According to the first and second embodiments,
Diaphragm 4 is configured using pentagonal and hexagonal polygons, but may be configured using other polygons than quadrangular.

According to the first embodiment, the diaphragm 4
Although the electrode plates 3 and 5 are provided inside and outside the so-called push-pull configuration, the electrode plate may be provided on only one of them, so-called single-type configuration.

[0050]

As described above, according to the first aspect of the present invention, a substantially spherical diaphragm having a conductive layer is provided on at least one of the inner peripheral side and the outer peripheral side of the diaphragm. An electroacoustic transducer comprising: an electrode plate having a spherical shape arranged at intervals; and an n-sided polygon (n: an integer of 4 or more).
And a triangle formed by a line segment drawn from the center of gravity of the (n + 1) polygon to each vertex is a combination of shapes that are folded into a V shape by a perpendicular drawn from the center of gravity to each side, and the center of gravity of each polygon is Are arranged at positions protruding in the direction in which the radius increases, the legs of the perpendicular drawn on each side are bent in the direction in which the radius decreases, and both sides drawn on the common side of adjacent polygons Since the legs of the perpendicular line are configured to be continuous, the triangular portion having the vertex of the polygon as a vertex becomes a shape that can easily change in the radial direction with the center of gravity of the polygon as a fixed point, so that the vibration plate and the electrode plate A capacitor is formed between them, and a situation in which an electrostatic effect is generated is realized, whereby a sound source (spherical wave sound field) close to a respiratory sphere vibrating in the radial direction is realized, and the amplitude of the vibration is increased. Can output loud sound It is.

According to the second aspect of the present invention, the diaphragm of the electroacoustic transducer according to the first aspect is formed into a substantially spherical shape by joining a plurality of divided parts. In addition to the effects described above, it is easy to form the spherical shape of the diaphragm and also to easily form the mold.

According to the third aspect of the present invention, each triangle formed by a line segment drawn from the center of gravity of the polygon to each vertex is folded into a V shape by a perpendicular drawn from the center of gravity to each side. In the polygon, the center of gravity of each polygon is disposed at a position protruding in the direction in which the radius increases, and the leg of the perpendicular drawn on each side is bent in the direction in which the radius decreases, and A diaphragm that is configured so that the legs of both perpendiculars drawn on a common side are continuous, and that is provided with an opening in a part thereof; Since a sound output unit that outputs sound to the internal space of the plate is provided, the triangular portion having the vertex at the center of gravity of the polygon has a shape that is easily changed in the radial direction with the center of gravity of the polygon as a fixed point. The diaphragm vibrates in the radial direction due to the vibration of the part and becomes a respiratory sphere There sound source (spherical wave field) are those which are realized, large output audio by it is possible to increase the amplitude of the vibration can be obtained.

[Brief description of the drawings]

FIG. 1A is a sectional view of a spherical speaker (electrostatic electroacoustic transducer) showing a first embodiment of the present invention, and FIG. 1B is an enlarged sectional view of a diaphragm.

FIG. 2 is a sectional view of a hemisphere showing the first embodiment of the present invention.

3A is a front view of an outer electrode plate, and FIG. 3B is a bottom view thereof.

FIG. 4 is a perspective view of a diaphragm showing the first embodiment of the present invention.

FIG. 5 is a diagram illustrating a configuration of a diaphragm.

FIG. 6 is a diagram illustrating a vibration state of a diaphragm.

FIG. 7 is an enlarged sectional view showing a modified example of the diaphragm.

FIG. 8 is a schematic sectional view of a spherical speaker showing a second embodiment of the present invention.

FIG. 9 is a partially cutaway front view of a spherical speaker showing a modification of the second embodiment.

FIG. 10 is a sectional view of the basic shape of the diaphragm or the spherical diaphragm, for example, passing through the equator.

FIG. 11 is a development view of a pentagon and a hexagon related to one round passing through the equator.

FIG. 12 is a development view in which a pentagon and a hexagon relating to one round passing through the equator are developed and positions of polygonal lines are shown.

FIG. 13 shows a cross section of the basic shape of the diaphragm or the spherical diaphragm, for example, passing through the equator (shown by a thick line) and a cross section in which pentagonal and hexagonal bent surfaces are formed (shown by a thin line). FIG.

FIG. 14 is a diagram showing hexagons indicated by oblique lines in FIG. 13 and portions where hexagons are adjacent to each other.

15 is a diagram showing a tetrahedron formed by the ridge lines in FIG. 14 and coordinates for determining the shape of the tetrahedron.

FIG. 16 is a sectional view of a conventional speaker.

[Explanation of symbols]

3, 5 electrode 4 diaphragm 21 conductive layer O ₁ , O ₂ center of gravity v ₁ , v ₂ perpendicular t ₁ , t ₂ vertex 30 spherical diaphragm (diaphragm) 30 a opening 31 sound output unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5D012 AA03 BA03 CA01 CA13 FA01 GA02 5D016 AA05 BA03 CA03 DA02 EC02 FA01 GA03

Claims (3)

[Claims] 1. A substantially spherical diaphragm having a conductive layer,
An electroacoustic transducer including a spherical-shaped electrode plate disposed at least on one of an inner peripheral side and an outer peripheral side of the diaphragm at an interval, wherein an n-sided polygon (n: an integer of 4 or more) ) And (n + 1) polygons are each a triangle formed by a line segment drawn from the barycenter to each vertex, which is a combination of shapes that are folded into a V-shape by a perpendicular drawn from the barycenter to each side. The center of gravity is arranged at a position protruding in the direction in which the radius increases, and the leg of the perpendicular drawn on each side is bent in the direction in which the radius decreases, and both sides are drawn on the common side of the adjacent polygon. A diaphragm of an electro-acoustic transducer, characterized in that the legs of the perpendicular line are continuous. 2. The diaphragm for an electro-acoustic transducer according to claim 1, wherein the diaphragm is formed into a substantially spherical shape by joining a plurality of divided parts. 3. An n-gon (n: an integer of 4 or more) and (n +
1) Each 3 consisting of a line segment drawn from the center of gravity of the square to each vertex
A polygon is a combination of shapes folded in a V-shape by a perpendicular drawn from the center of gravity to each side, and is disposed at a position where the center of gravity of each polygon protrudes in a direction in which the radius increases, and is drawn on each side. The leg of the perpendicular is bent in the direction in which the radius becomes smaller, and both legs of the perpendicular drawn on the common side of the adjacent polygon are configured to be continuous, and an opening is partially formed. An electroacoustic transducer, comprising: a vibration plate provided; and a sound output unit fixed to the vibration plate and outputting sound to the internal space of the vibration plate through the opening.