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JP2006229934

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DESCRIPTION JP2006229934
The present invention provides a method of manufacturing an electro-acoustic transducer (150)
in which alignment of each part is simplified and assembly is facilitated and variation in
characteristics is suppressed. A diaphragm segment (101) having a regular pentagonal outer
shape (14) inscribed in a circle of one diameter (D2) from diaphragm material, and a plurality of
diaphragm segments in plan view Developing the upper side, aligning the apexes and joining the
sides which can be arranged in parallel with each other by the flexible connecting member (102)
in this arrangement state; and the base body (130) of the regular dodecahedron A plurality of
drive units (232) each having a voice coil bobbin (221) on each surface (132a) for vibrating each
of the plurality of diaphragm segments are extended in a direction orthogonal to each surface of
the regular dodecahedron And fixing each voice coil to the inner surface of each of the plurality
of diaphragm segments. [Selected figure] Figure 13
Method of manufacturing electroacoustic transducer
[0001]
The present invention relates to a method of manufacturing an electroacoustic transducer.
[0002]
An electroacoustic transducer including a diaphragm, a frame for supporting the outer periphery,
and a drive unit having a magnetic circuit for vibrating the diaphragm in one axial direction to
emit sound is generally referred to as a speaker, and the diaphragm As a cone-shaped one is
often used.
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This cone shape is a surface shape of a truncated cone having an inner periphery and an outer
periphery in which an inclined portion inclined with respect to a central axis which is a vibration
direction is cut off a top portion of a rotationally symmetric cone (circular cone) about the central
axis It is generally considered to be. By the way, it is known that in this substantially frustoconical diaphragm, a standing wave is generated in the radial direction over the entire
circumference of the diaphragm, and peaks and dips are easily generated on the frequency-sound
pressure characteristics.
[0003]
Therefore, in order to make it difficult to generate the peaks and dips, it has been proposed that
the frusto-conical shape of the diaphragm has a shape in which the central axis of the inner
periphery is eccentric from the central axis of the outer periphery. In this eccentrically-shaped
diaphragm, the distance from the inner peripheral end to the outer peripheral end of a line
passing through the central axis of the inner peripheral is different depending on the
circumferential position. Therefore, the wavelength of the standing wave generated on the
diaphragm differs depending on the position in the circumferential direction, and peaks and dips
on the frequency-sound pressure characteristic are smoothed.
[0004]
Thus, although this eccentrically-shaped diaphragm can make it difficult to generate peaks and
dips on the frequency-sound pressure characteristics, it is a general-purpose diaphragm whose
outer shape is formed non-eccentrically with respect to the central axis of the inner periphery.
There is a problem that magnetic circuit parts or a frame can not be diverted. Then, the structure
which eliminates this malfunction is described in patent document 1. FIG. This structure is a
structure for attaching the above-described eccentrically shaped diaphragm to a magnetic circuit
component or a frame whose outer shape is formed non-eccentrically with respect to the central
axis.
[0005]
On the other hand, there is known an electro-acoustic transducer which has a substantially
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spherical shell-shaped diaphragm and vibrates it radially to emit sound in all directions with
respect to the center of the diaphragm. The electro-acoustic transducer may be referred to as a
sphere speaker or a breathing sphere speaker, and examples thereof include those disclosed in
Patent Document 2 and Patent Document 3. In these documents, as an example of the diaphragm
of the electro-acoustic transducer, one in which a plurality of diaphragms of a predetermined
shape formed substantially in the plane are combined to form a diaphragm having a substantially
spherical shape is described. JP-A-9-284886 JP-A-2000-78686 JP-A-2001-95088
[0006]
By the way, if the eccentric diaphragm as described in Patent Document 1 is applied to the
substantially spherical shell-like diaphragms described in Patent Documents 2 and 3 in order to
suppress the generation of standing waves, It is expected that the frequency-sound pressure
characteristics will be improved as well. However, when combining a plurality of diaphragms that
are eccentric, if the eccentric axis of the diaphragm is disposed at a position where the spheres
are equally divided, the junction with the adjacent diaphragm is described as an edge or
mounting member in Patent Document 1 There is a need for special bonding members having
different radial and width widths as described above, and there is a problem that alignment
during assembly is extremely difficult and the characteristics vary. Further, since the speakers
described in Patent Documents 2 and 3 are configured to be driven by one drive unit, it is
difficult to increase the output sound pressure, and improvement has been desired.
[0007]
Therefore, the problem to be solved by the present invention is to divide the surface of a
substantially spherical surface into a plurality of polygonal segments, connect the boundaries of
each segment with an elastic material to create a polyhedral spherical shell diaphragm, and
vibrate each segment When assembling an electro-acoustic transducer having a structure in
which a plate is driven by individual driving units, the method of manufacturing the electroacoustic transducer can be simplified by simplifying the alignment of each part to facilitate
assembly, and suppressing variation in characteristics. It is to provide.
[0008]
In order to solve the above problems, the present invention has the following procedures [1] to
[3] as a means.
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[1] creating a diaphragm segment (10, 10R, 100, 101) having a regular pentagonal outer shape
(14) inscribed in a circle of one diameter (D2) from a diaphragm material; The diaphragm
segment (10, 10R, 100, 101) is developed on a plane, and the connection members (102) having
flexibility in the arrangement state can be disposed on the sides where the apexes can be aligned
and opposed in parallel. And a voice coil bobbin (221) is provided on each surface (132a) of a
base (130) having an outer shape of a regular dodecahedron, and each of the plurality of
diaphragm segments (10, 10R, 100, 101) Fixing a plurality of drive units (232) for vibrating each
of the voice coil bobbins (221) so as to extend in a direction orthogonal to the respective
surfaces (132a) of the regular dodecahedron Fixing the voice coil (221) to the inner surface of
each of the plurality of diaphragm segments (10, 10R, 100, 101). A method of manufacturing an
electroacoustic transducer (150) It is. [2] The plurality of diaphragm segments (10, 10R, 101)
have projection shapes on a plane (P0) including the outer portion (14) around the central axis
(O) of the one diameter (D2) An inner-shaped portion (13) which has a rotationally symmetric
shape and protrudes to one side with respect to the plane (P0), and connects the outer-portion
(14) and the inner-shaped portion (13) (O) A vibrating surface portion (12) having an inclined
surface inclined with respect to (O), wherein the vibrating surface portion (12) has the center in
any cross section (SS) orthogonal to the central axis (O) It is a manufacturing method of the
electroacoustic transducer (150) as described in [1], which has a rotationally symmetrical shape
about an eccentric shaft (O2) eccentric to the shaft (O). [3] Each of the plurality of diaphragm
segments (100, 101) is in the shape of a regular n-gon (n: an integer of 4 or more) inscribed in a
circle having an outer diameter (D2) of the external part (14) The n triangles (TR1 to TRn)
obtained by dividing the n polygon into n pieces by a line segment (T1G to TnG) connecting the
center (G0) of the n shape and the vertices (T1 to Tn) There are n apexes (TP1 to TPn) provided
one inside each and the line segments connected to the respective apexes (T1 to Tn) and the
center (G0) have ridges (TP1 to TPn), and the n apexes TP1 to TPn) are characterized in that they
are on the outer peripheral line (C2) of a figure rotationally symmetric about an eccentric axis
(G3) eccentric to the central axis (G0) of the regular n-gon, as in [1] It is a manufacturing method
of an electroacoustic transducer (150) of a statement.
[0009]
According to the present invention, the alignment of each part is simplified, the assembly
becomes easy, and the variation of the characteristics is suppressed.
[0010]
An embodiment of the present invention will be described by way of a preferred embodiment
with reference to FIGS.
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FIG. 1 is a schematic perspective view showing a first embodiment of a diaphragm applied to the
present invention. FIG. 2 is a plan view and a sectional view showing a first embodiment of the
diaphragm applied to the present invention. FIG. 3 is a cross-sectional view showing an electroacoustic transducer using the first embodiment of the diaphragm applied to the present
invention. FIG. 4 is a cross-sectional view showing another example of the electroacoustic
transducer using the first embodiment of the diaphragm applied to the present invention. FIG. 5
is a schematic view for explaining the standing wave distribution in the conventional diaphragm.
FIG. 6 is a schematic view for explaining the standing wave distribution of the diaphragm applied
to the present invention. FIG. 7 is a graph showing frequency-sound pressure characteristics
according to the amount of eccentricity of the diaphragm. FIG. 8 is a schematic cross-sectional
view for explaining the shape of a diaphragm applied to the present invention. FIG. 9 is a
schematic cross-sectional view for explaining the shape of the first embodiment of the diaphragm
applied to the present invention. FIG. 10 is a plan view and a sectional view showing a
modification of the first embodiment of the diaphragm applied to the present invention. FIG. 11
is a front view for comparing and explaining a conventional diaphragm and a second
embodiment of the diaphragm applied to the present invention. FIG. 12 is an external view
showing the electroacoustic transducer manufactured in the example according to the present
invention. FIG. 13 is a developed view of a diaphragm for explaining an embodiment according to
the present invention. FIG. 14 is a partial cross-sectional view for explaining the electro-acoustic
transducer manufactured in the example according to the present invention. FIG. 15 is a
perspective view for explaining the structure of the electroacoustic transducer manufactured in
the embodiment according to the present invention. FIG. 16 is a partial cross-sectional view for
explaining the structure of the electroacoustic transducer manufactured in the example
according to the present invention. FIG. 17 is another perspective view for explaining the electroacoustic transducer manufactured in the embodiment according to the present invention. FIG. 18
is a front view and a perspective view for explaining another form of the diaphragm used in the
electroacoustic transducer manufactured in the example according to the present invention. FIG.
19 is a front view for explaining the electroacoustic transducer manufactured in the example
according to the present invention. In the following description, rotational symmetry means at
least two or more rotational symmetries.
[0011]
<About the diaphragm element> In the electroacoustic transducer manufactured according to the
present invention, a spherical shell diaphragm having a substantially spherical shell shape is used
as a diaphragm by connecting a plurality of diaphragms. A first embodiment of the diaphragm
will be described with reference to FIG. 1 and FIG. FIG. 1 shows a plurality of radial solid lines 16
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schematically showing the curvature so that the curved surface shape of the diaphragm can be
easily understood. FIG. 1 is a perspective view showing the appearance of the diaphragm 10, FIG.
2 (a) is a plan view showing the diaphragm 10, and FIG. 2 (b) is S1-S1 in FIG. 2 (a). FIG.
[0012]
As shown in FIGS. 1 and 2, the diaphragm 10 has a central portion 11 ranging from a central axis
O to a diameter D1 [see FIG. 2 (a)] and a diameter D2 from the inner diameter portion 13 to the
diameter D2. It forms in the substantially disk shape which consists of the inclination part 12
which is the range to the outer-diameter part 14 which becomes [refer FIG. 2 (a)]. The material of
the diaphragm is not particularly limited, and sheets made of paper, resin such as PP
(polypropylene), metal such as aluminum, ceramic, or wood may be used.
[0013]
The inner diameter portion 13 is formed so as to protrude by the maximum height h1 [see FIG. 2
(b)] with respect to the reference plane P0 including the outer diameter portion 14, and the
central portion 11 inside thereof is the most projecting portion. It has a curved surface which is
recessed with respect to a certain inner diameter portion 13 by a depth h2 (see FIG. 2B).
Accordingly, the inner diameter portion 13 forms a circular ridge having a diameter D1. The
inclined portion 12 is formed as a surface connecting the inner diameter portion 13 and the
outer diameter portion 14. In addition, an intermediate diameter portion 15 (indicated by a twodot chain line) having a diameter D3 is formed between the inner diameter portion 13 and the
outer diameter portion 14. The intermediate diameter portion 15 is a portion (inflection portion)
where the curvature of the surface of the inclined portion 12 changes significantly.
[0014]
More specifically describing the diaphragm 10, the surface (hereinafter referred to as the
inclined portion inner side surface 12a) of the region on the inner side (the side of the central
axis O) of the intermediate diameter portion 15 in the inclined portion 12 has a curvature in the
concave direction. As a curved surface, the surface of the region outside the intermediate
diameter portion 15 (opposite to the central axis O) (hereinafter referred to as the inclined
portion outer surface 12b) is formed as a flat surface having no curvature. . Further, the
intermediate diameter portion 15 has a central axis O2 eccentric to the central axis O of the
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inner diameter portion 13 and the outer diameter portion 14 by a distance α (an eccentricity
amount α). Therefore, with the intermediate diameter portion 15 as a boundary, a portion where
the curvature is discontinuous between the eccentric central surface O2 side surface (inclined
inner surface 12a) and the opposite surface (inclined outer surface 12b) And is shown as a line
circling about the eccentric central axis O2.
[0015]
In addition, the curvature R of the inner surface 12a of the inclined portion is not constant, and
changes continuously from the maximum Rmax to the minimum Rmin in the circumferential
direction (see FIG. 2B), based on the changing curvature R and the eccentric distance α. Thus,
the inclined inner surface 12a is formed.
[0016]
Next, an electroacoustic transducer 50 using the above-described diaphragm 10 will be
described.
The electro-acoustic transducer 50 is also referred to as a speaker unit, and for example, as
shown in FIG. 3, a diaphragm 10 and a flexible edge 30 connected to the outer diameter portion
14 side of the diaphragm 10; A housing 31 to which the edge 30 is fixed and a magnetic circuit
34 fixed to the housing 31 for driving the diaphragm 10 are included.
[0017]
The magnetic circuit 34 includes a cup-shaped yoke 23 having a bottom 23 and an annular wall
23 b, a magnet 24 fixed to the inner surface of the bottom 23 a, and a cylindrical pole piece 25
fixed to the magnet 24. Configured The edge 30 which connects the diaphragm 10 and the
housing 31 can use a rubber material or a resin material as an example. The voice coil bobbin 21
and the voice coil 22 wound around the outer peripheral surface on one end side thereof are
inserted into the gap between the annular wall portion 23 b of the yoke 23 and the pole piece
25. The voice coil 22 is externally charged through a lead wire 22 a, and the lead wire 22 a is
drawn out from a hole 31 a provided in the housing 31. Further, the voice coil bobbin 21 is
connected to the housing 31 by the damper 33 having an outer peripheral surface thereof having
elasticity, and the housing 31 can freely vibrate in a direction (vibration direction) parallel to the
central axis O of the diaphragm 10 via the damper 33. It is supported by A drive unit 32 is
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configured to include the magnetic circuit 34, the voice coil bobbin 21 and the voice coil 22.
[0018]
Although partially overlapping, in more detail, the diaphragm 10 has a flexible annular edge 30
fixed in the vicinity of the outer diameter portion 14, and the outer peripheral portion of the
edge 30 is the annular shape of the housing 31. It is fixed to the frame 31b. At the time of this
fixing, the diaphragm 10 is attached in such a direction that the inner diameter portion 13
protrudes on the opposite side to the drive portion 32.
[0019]
One end of a circular voice coil bobbin 21 is fixed to the surface on the opposite side to the
projecting direction of the circular ridge-shaped projecting inner diameter portion 13. A voice
coil 22 is wound around the outer peripheral surface of the other end of the voice coil bobbin 21.
Further, the cup-shaped yoke 23 is disposed such that the inner wall surface 23a faces the voice
coil 22 with a predetermined magnetic gap.
[0020]
On the other hand, the outer peripheral surface of the disk-shaped pole piece 25 connected to
the cylindrical magnet 24 has a predetermined gap with the inner surface of the voice coil
bobbin 21 inside the portion of the voice coil bobbin 21 where the voice coil 22 is wound. Are
arranged to face each other. The voice coil bobbin 21 is supported by the housing 31 via the
damper 33 so as to be movable in the vibration direction.
[0021]
The edge 30, the housing 31, and the drive unit 32 used in the above-described electroacoustic
transducer 50 can use general-purpose components whose outer shape is formed noneccentrically with respect to the central axis O as they are. Since it is not necessary to use, cost
increase can be suppressed.
[0022]
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The direction in which the inner diameter portion 13 of the diaphragm 10 protrudes with respect
to the drive portion 32 may be directed to the drive portion 32 side in the opposite direction to
the direction of FIG. 3 described above.
That is, the configuration is such that the inner diameter portion 13 is in a depression direction,
and this example is shown in FIG. In the electro-acoustic transducer 50A of FIG. 4, the projecting
direction of the diaphragm 10 is opposite to that of the electro-acoustic transducer 50 of FIG. 3,
and one end side of the voice coil bobbin 21 corresponds to the inner diameter portion 13 of the
diaphragm 10. It adheres to the surface of the side which protruded. Other than this is the same
as the electroacoustic transducer 50. Therefore, as the voice coil bobbin 21, one having a length
in the central axis O direction shorter than that used for the electroacoustic transducer 50 can be
used.
[0023]
The electroacoustic transducer 50 in which the inner diameter portion 13 protrudes to the
outside as shown in FIG. 3 has a wider directivity than the electroacoustic transducer 50A in
which the inner diameter portion 13 falls to the inside as shown in FIG. It is suitable for an
electro-acoustic transducer (so-called tweeter) that outputs high-pitched sound whose directivity
is hardly wide. Further, the electro-acoustic transducer 50A in which the inner diameter portion
13 is depressed inward is suitable for a large aperture electro-acoustic transducer (so-called
woofer) because the diaphragm 10 does not protrude outward.
[0024]
Next, in the case where the diaphragm 10 having the central axis O2 eccentric to the central axis
O of the outer diameter portion 14 as described above is used, and the central axis O2 of the
intermediate diameter portion 15 is The comparison of the characteristics etc. in the case where
the diaphragm which is not eccentric | decentered is used, and is demonstrated below.
[0025]
5 and 6 show a diaphragm 10a (comparative example) in which the central axis O2 of the
intermediate diameter portion 15 is not eccentric with respect to the central axis O, and a central
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axis O2 in which the intermediate diameter portion 15 is eccentric. The state of vibration of the
diaphragm with respect to the diaphragm 10 used for the electroacoustic transducer
manufactured by the manufacturing method of the invention is shown.
5 and 6 apply to the voice coil 22 a force obtained from the effective coil length and the number
of turns of the voice coil 22 under the actual magnetic field strength of the magnetic circuit 34
as an analysis condition of the vibration, The distribution of the standing wave in the AA cross
section of the central axis O direction of each diaphragm when vibration is 12 kHz is shown.
[0026]
In these drawings, the upper drawing is a plan view of the diaphragm, and the displacement of
the vibration is shown on the lower side correspondingly. Specifically, in the lower displacement
amount diagram, the broken line indicates the cross-sectional shape of the diaphragm, and the
solid line indicates the standing wave distribution. In addition, this displacement amount is drawn
exaggeratingly. From the comparison of the figures, it can be seen that the standing wave is
clearly asymmetric with respect to the central axis O when the diaphragm 10 is used. In addition,
the number of peaks significantly generated with respect to the central axis O is also different.
[0027]
FIG. 7 shows the diaphragm 10a as a comparative example shown in FIG. 5 in which the central
axis O2 of the intermediate diameter portion 15 and the central axis O coincide (that is, the
eccentricity is 0.0 mm), and the central axis of the intermediate diameter portion 15 The
frequency-sound pressure characteristic in the electroacoustic transducer which used O2 and
two examples of the diaphragm 10 which carried out eccentricity 1.5 mm and 3.0 mm as
eccentricity (alpha) from the central axis O is shown, respectively.
[0028]
When the diaphragm 10a which is a comparative example is used, a deep dip is observed in the
vicinity of 8 kHz (refer to the arrow). However, if there is eccentricity as in the two types of
examples, this dip is embedded as the amount increases. It can be seen that planarization is more
achieved.
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Also, it is understood that the other peaks and dips become smooth by decentering, and become
flatter as the amount of eccentricity α becomes larger.
[0029]
By the way, the inclined portion inner side surface 12a of the portion between the inner diameter
portion 13 and the intermediate diameter portion 15 is, for example, a curved surface as shown
in FIGS. May be [FIGS. 8 (a) to 8 (c) are schematic views showing the case where the intermediate
diameter portion 15 has a central axis O2 eccentric to the left direction of the figure with respect
to the central axis O of the outer diameter portion 14] There is. Specifically, FIGS. 8 (a) and 8 (c)
are examples in which the inclined portion inner side surface 12a is an inclined curved surface
having a curvature that is recessed inward in this cross-sectional shape. Further, in FIG. 8B, while
the inclined portion inner side surface 12a is an inclined surface having a curvature such that the
inner diameter portion 13 side is concaved inward in this cross sectional shape, the outer
diameter portion 14 side has a curvature in the cross sectional shape. It is an example made into
the inclined plane which does not have.
[0030]
On the other hand, the sloped portion outer side surface 12b of the portion between the
intermediate diameter portion 15 and the outer diameter portion 14 of the sloped portion 12
may be a curved surface as shown in FIGS. 8 (a) to 8 (c). Specifically, as shown in FIG. 8A, it may
be a non-inclined plane, or it may be an inclined plane that is continuous from the inner side
surface 12a of the inclined portion connected as shown in FIG. 8B. Further, as shown in FIG. 8C,
it may be an inclined curved surface which is inclined in the opposite direction to the inclined
portion inner side surface 12a, or an inclined flat surface 12b1 as shown by a broken line.
[0031]
Further, the inclined portion inner side surface 12a may be an inclined plane having no curvature
in the cross-sectional shape as shown in FIGS. 9 (a) to 9 (c). (FIGS. 9A to 9C are also schematic
views, showing the case where the intermediate diameter portion 15 has a central axis O2
eccentric to the left direction of the figure with respect to the central axis O of the outer diameter
portion 14 ing. In addition, the inclined portion outer side surface 12b may be a non-inclined flat
surface as shown in FIG. 9A, or may be an inclined flat surface inclined in the same direction as
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the inclined portion inner side surface 12a as shown in FIG. As shown in 9 (c), it may be an
inclined plane inclined in the opposite direction to the inclined portion inner side surface 12a.
[0032]
Of course, the shape of the inclined portion 12 may be a combination of those shown in FIGS. 8
and 9, and is not limited thereto. As shown in FIGS. 8 and 9, in the diaphragm 10, the crosssectional shape in the S-S cross section orthogonal to the central axis O has a central axis O5
eccentric with the central axis O by α2 The rotationally symmetrical shape about the eccentric
center axis O5 is obtained.
[0033]
In the inclined portion 12, the position d1 of the reference plane P0 including the outer diameter
portion 14 in the direction of the central axis O (the position where the reference plane P0
intersects the central axis O) to the position d2 of the inner diameter portion 13 (in the central
axis O) The cross section having a rotationally symmetrical shape about such an eccentric central
axis O5 is not limited to the one having a rotationally symmetrical shape about the eccentric
central axis O5 at all positions up to the surface P13 including the inner diameter portion 13)
The diaphragm may have a shape in which the position d partially exists as an eccentric surface
portion.
[0034]
Further, except for the example shown in FIG. 8B, the intermediate diameter portion 15 is a
portion where the inclination angle or the curvature of the surface of the inclined portion 12
suddenly changes, in other words, two portions connecting the portion as a boundary. It is set as
a portion where the curvature or inclination angle of the surface is discontinuous.
In addition, the intermediate diameter portion 15 is a portion visually recognized as a boundary
line in which the degree of reflection of light projected from one direction is different. The
intermediate diameter portion 15 is not limited to a perfect circle, and may be a rotationally
symmetrical figure having a central axis O2 eccentric to the central axis O and having the
eccentric center O2. Further, the inner diameter portion 13 is not limited to a perfect circle, and
may be, for example, a rotationally symmetric figure such as an ellipse.
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[0035]
Although the example mentioned above demonstrated diaphragm 10 which has a field where
central part 11 was dented, central part 11 may be a plane and may have a field which
protrudes. Further, the size of the central portion 11, in other words, the radial size of the inner
diameter portion 13 may be set arbitrarily. Therefore, for example, when the inner diameter
portion 13 is a true circle, the size of the diameter D1 is arbitrary.
[0036]
Although the diaphragm 10 mentioned above demonstrated the example whose the external
shape is circular, it is good also as an external shape inscribed in a circle (for example, regular
pentagon). In this case, the dimensions may be set so that the outer shape of the polygon and the
intermediate diameter portion do not interfere with each other. Further, as shown in FIG. 10, the
inclined portion outer side surface 12b may be a curved surface having a curvature center O4 on
the side opposite to the projecting direction of the inner diameter portion 13. FIG. 10 shows, as
an example, the cross-sectional shape of a diaphragm 10R in which the inclined portion outer
side surface 12b is formed by a curved surface along a spherical surface CF having a radius R1.
The diaphragm 10R has the same shape as the diaphragm 10 of FIG. 2 except for the inclined
portion outer side surface 12b.
[0037]
As described above, since the inner diameter portion 13, the outer diameter portion 14 and the
middle diameter portion 15 are not limited to the circle, including the case of the circle, the inner
shape portion 13, the outer shape portion 14 and the middle shape portion 15 respectively. It
can be written as
[0038]
The diaphragm 10 described in detail above has a central axis in which the outer diameter
portion 14 and the inner diameter portion 13 are coaxial even if there is an intermediate
diameter portion 15 having a central axis O2 eccentric to the central axis O of the outer diameter
portion 14 Since O is included, the electroacoustic transducer (speaker unit) 50 can be
configured using the drive unit 32 having the general edge 30, the housing 31, or the magnetic
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circuit 34.
In addition, again, the outer diameter portion 14 and the inner diameter portion 13 are formed to
have the central axis O of the coaxial, and the center which is eccentric from the central axis O of
the outer diameter portion 14 and the inner diameter portion 13 by a predetermined distance α
When the intermediate diameter portion 15 having the axis O2 is provided, generation of a
symmetrical standing wave with respect to the central axis O is suppressed, and peaks and dips
in the frequency-sound pressure characteristic are smoothed to smooth it. Can. In the inclined
portion 12, the cross-sectional shape in any S-S cross section orthogonal to the central axis O has
a central axis O5 eccentric to the central axis O and rotates about the eccentric central axis O5.
Also in the case of a symmetrical shape, generation of a symmetrical standing wave with respect
to the central axis is similarly suppressed, and peaks and dips in the frequency-sound pressure
characteristics can be smoothed out.
[0039]
Next, a diaphragm 100 of a second embodiment used for the electroacoustic transducer
manufactured by the manufacturing method of the present invention will be described with
reference to FIG. FIG. 11 shows the diaphragm 100a of the basic shape as FIG. 11 (a) and the
diaphragm 100 of the second embodiment as FIG. 11 (b) in order to make it easy to grasp the
shape of the diaphragm 100. It is a typical top view. In addition, in FIGS. 11A and 11B, black
circles are attached to points where the line segments intersect for easy understanding.
[0040]
This diaphragm 100 shown in FIG. 11B is positioned on the central axis O of the outer shape
with the diameter D1 which can be arbitrarily set in the inner diameter portion 13 of the first
embodiment as substantially zero, and the outer diameter portion The top portion TP0 is located
at a position projecting to one side with respect to the reference plane P0 set by including 14
while rotating around an axis eccentric to the central axis O between the top portion TP0 and the
outer shape It is a diaphragm in which a symmetrical virtual figure is set and a plurality of
apexes projecting on the same side as the apex TP0 are provided on this imaginary figure.
[0041]
The diaphragm 100 has a shape in which a plane substantially orthogonal to the sound radiation
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direction (direction of the central axis O) is almost eliminated.
The outer shape of the diaphragm 100 may be a regular n-gon (n: an integer of 4 or more). Here,
as shown in FIG. 11B, an example of a regular pentagon in which n = 5 is described.
[0042]
First, a diaphragm 100a having a basic shape shown in FIG. 11 (a) will be described. The
diaphragm 100a is a regular pentagon whose outer shape has apexes T1 to T5. Each vertex is
located on the circumscribed circle C1. It is surrounded by the line segments T1G to T5G
connecting the center G0 of the regular pentagon (hereinafter also referred to as the main center
G0) and the vertices T1 to T5 and the sides T1T2 to T5T1 which are line segments connecting
between adjacent vertices The five triangles TR1 to TR5 and the centers of gravity G1 to G5 of
these triangles TR1 to TR5 are set. (In the example of this diaphragm 100a, each gravity center
G1-G5 corresponds with each center of triangle TR1-TR5)
[0043]
Here, the diaphragm 100a has a top portion TP0 at which the main center G0 and the positions
of the respective gravity centers G1 to G5 protrude to one side with respect to a reference plane
P0 determined by including the respective apexes T1 to T5. And it is set as the shape which has
the uneven surface broken by each line segment so that it may become top part TP1-TP5.
Specifically, the line segments T1G to T5G connecting the vertices T1 to T5 and the main center
G0 are valley folds that become valley lines, and ten lines connecting the vertices T1 to T5 and
the centers of gravity G1 to G5 A mountain fold is used as the ridge line (mountain line). Further,
the five top portions TP1 to TP5 are located on a circle C2 centered on the main center G0.
[0044]
With respect to the diaphragm 100a of the basic shape having such a concavo-convex surface, as
shown in FIG. 11B, in the diaphragm 100 of the second embodiment, the positions of the tops
TP1 to TP5 are adjacent to each other. A predetermined amount α from a regular pentagonal
main center O (which coincides with the center of gravity G0 in this example) whose outline
connects the center O3 of the circle C2 so that the line connecting the apexes TP1 to TP5 is on
12-05-2019
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the circle C2. It has a shape moved so as to be eccentric. FIG. 11B shows an example in which the
eccentric direction is a direction (arrow direction) approaching the vertex T1.
[0045]
Further, the diaphragm 100 is formed such that the main center G0 (the top portion TP0) and
the top portions TP1 to TP5 project to one side with respect to the reference plane P0. Each
protrusion amount with respect to the reference plane P0 may be arbitrary. Therefore, the main
center G0 (top portion TP0) may be most protruded with respect to the reference plane P0, and
may be smaller (lower) than any of the top portions TP1 to TP5. Of course, the amount of
protrusion may be the same. As described above, it is preferable that all the tops TP0 to TP5 be
in a position where they project to one side with respect to the reference plane P0, but only the
tops TP1 to TP5 may be in a position where they project to one side. Further, a line segment
connecting such apexes TP1 to TP5 with the respective apexes T1 to T5 and the main center G0
is a ridge line which is a mountain fold line.
[0046]
Here, when the main center G0 is lower than the tops TP1 to TP5, the ridge line going from each
of the tops TP1 to TP5 to the main center G0 is down, but the ridge line going from each vertex
T1 to T5 to the main center G0 is up Therefore, the main center G0 is conveniently referred to as
the top TP0. Similarly, when the main center G0 is higher than the respective tops TP1 to TP5,
the ridge line extending from the main center G0 to each of the tops TP1 to TP5 is downward,
but the ridge line extends from each apex T1 to T5 to the respective tops TP1 to TP5 The tops
are referred to as tops TP1 to TP5 for convenience.
[0047]
In the case where the amount of protrusion of each of the top portions TP1 to TP5 with respect
to the reference plane P0 is different, the vibration plate 100 may not have all the top portions
TP1 to TP5 included in the same plane. Further, all the top portions TP1 to TP5 may be included
in the same plane, and the plane may be nonparallel to the reference plane P0.
[0048]
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16
The diaphragm 100 according to the second embodiment is not limited to the one having the
above-mentioned regular pentagonal shape but may be one having the regular n-gonal shape.
That is, this diaphragm has an outer shape of a regular n-gon (n: an integer of 4 or more), and the
n-divided n-division by a line connecting the center (centroid) G0 and each vertex T1 to Tn The
center O3 of the figure drawn by the line C2 connecting the points TP1 to TPn is a regular n-gon
shape, and the positions of arbitrary points TP1 to TPn in each range in n triangles TR1 to TRn
obtained by The center G0 and the points TP1 to TPn are set to be eccentric from the center G0
by a distance α, and are positioned as apexes projecting on one side with respect to a reference
plane P0 set by including the respective apexes T1 to Tn. It is a diaphragm having a shape.
[0049]
Here, the line C2 connecting the points TP1 to TPn may not be a circle, and may be a rotationally
symmetric figure. The main center G0 and the apexes TP1 to TPn may protrude to one side with
respect to the reference plane P0 including the vertices T1 to Tn, and the amount of projection
with respect to the reference plane P0 is arbitrary. As described above, it is preferable that all the
tops TP0 to TPn be in a position where they project to one side with respect to the reference
plane P0, but only the tops TP1 to TPn may be in a position where they protrude to one side. In
addition, a line segment connecting such apexes TP1 to TPn, the apexes T1 to Tn, and the main
center G0 is a ridge line which is a mountain fold line.
[0050]
Therefore, the main center G0 may be most protruded with respect to the reference plane P0,
and may be smaller (lower) than any of the tops TP1 to TPn. Of course, the amount of protrusion
may be the same. In the diaphragm 100, the respective top portions TP1 to TPn may not be all
included in the same plane when the projection amounts of the top portions TP1 to TPn with
respect to the reference plane P0 are different. In this case, the tops TP1 to TPn may be included
in the same plane, and the plane may not be parallel to the reference plane P0.
[0051]
The inner peripheral portion of the edge 30 is connected to the outer peripheral portion of the
diaphragm 100 using the diaphragm 100 described above and an edge having an inner
peripheral shape corresponding to the outer shape of the diaphragm 100 and having a circular
12-05-2019
17
outer shape. If the peripheral portion of the edge 30 is fixed to a general-purpose frame having a
circular frame, the diaphragm 100 is supported by the frame via the edge 30 so as to be
vibratably supported by the frame. The speaker unit can be manufactured easily and with less
cost increase using a drive unit having a general-purpose frame or a magnetic circuit.
[0052]
Further, in the diaphragm 100, it is preferable to join the voice coil bobbin 21 at a position
corresponding to at least each of the top portions TP1 to TPn because the vibration of the voice
coil bobbin 21 can be transmitted to the diaphragm 100 more efficiently.
Further, if the voice coil bobbin 21 is fixed to the surface of the diaphragm 100 opposite to the
side where the tops TP1 to TPn project, wider directivity can be obtained. An example in which
the diaphragm 100 and the voice coil bobbin 21 are connected in this manner is schematically
shown in FIG. In this FIG. 12, the sound is emitted so as to have broad directivity characteristics,
as indicated by the arrows in the figure. FIG. 12 corresponds to the B-B cross section of the
diaphragm 100 shown in FIG. 11B, where the intersection of the line segment T1G on the
diaphragm 100 and the circle C2 as a rotationally symmetric figure is BC1 and the side T3T4.
The middle point of is BC2.
[0053]
The voice coil bobbin 21 is formed to have a cylindrical portion 21 a and a joint portion 21 b
connected to one end side thereof and enlarged toward the opening side. The voice coil 22 is
wound around the outer peripheral surface of the other end side of the cylindrical portion 21a.
The tip of the joint portion 21 b is adhesively fixed at a position corresponding to a circle C2 (see
FIG. 11B) connecting the top portions TP1 to TP5 of the diaphragm 100. Further, the voice coil
bobbin 21 is fixed so that its tube axis Ob and an axis passing through the top portion TP0 of the
diaphragm 100 and orthogonal to the reference plane P0 (that is, the central axis O of the outer
shape of the diaphragm 100) coincide. Ru. The tube axis Ob of the voice coil bobbin 21 coincides
with the central axis of the drive unit 32.
[0054]
In the electroacoustic transducer using this diaphragm 100, the distribution of the standing wave
becomes asymmetric with respect to the axis in any cross section including the central axis O,
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and the frequency − as described above with reference to FIG. The effect is obtained that the dip
or peak in the sound pressure characteristic is flattened.
[0055]
Further, in the electro-acoustic transducer using this diaphragm 100, the diaphragm 100 has no
plane orthogonal to the central axis O, and both planes are inclined, so that the center which is
the front of the diaphragm 100 is Even in the high sound range where the listening area close to
the axis O tends to have high sound pressure and sharp directivity, the decrease in sound
pressure (difference in sound pressure to the front) caused by the angle made with respect to the
central axis O becomes small. Properties close to sex are obtained.
If the directional characteristics have characteristics close to omnidirectional, they are useful in
use environments where the listening position is not limited to a narrow range, for example, use
in halls, large rooms, streets, etc., and are close to this electroacoustic transducer In the case of
listening at a position, localization of the sound does not greatly shift even if the listening
position is shifted, and it is very preferable because the user can listen with natural localization
movement.
[0056]
Furthermore, in the diaphragm 100 of the second embodiment, the diaphragm shape capable of
obtaining a characteristic with less sound pressure difference depending on the listening position
and a property close to no directivity in the diaphragm 100 of the second embodiment is
intensively studied with respect to the reference plane P0. It has been found that the main center
G0 protrudes most, and the protruding main center G0 and the tops TP1 to TPn and the apexes
T1 to Tn of the outer shape are included in the spherical surface with a constant curvature. This
is because the diaphragm 100 as a whole has a shape close to a part of a spherical surface,
although there are fine irregularities in the surface shape. Therefore, the radiation axis in the
sound emitting direction is more uniformly distributed in the direction orthogonal to the
spherical surface throughout the diaphragm 100.
[0057]
Therefore, in the electroacoustic transducer using the diaphragm 100 of this shape, not only is
the dip or peak in the frequency-sound pressure characteristic flattened, but also the sound
12-05-2019
19
pressure difference due to the difference in the angle made with respect to the vibration
direction of the diaphragm. Becomes smaller, and the near directivity is obtained.
[0058]
Here, when n having a regular n-gon indicating the outer shape of diaphragm 100 of the second
embodiment described above is infinite, the outer shape of diaphragm 100 becomes a circle, and
the plurality of top portions TP1 to TPn are infinite. It is the top of a large number.
The top of the infinite number is a circumferential line (diaphragm) in which this is a line which
continuously revolves around the central axis O, and the curvature or inclination angle of the two
surfaces connected with the line as a boundary is discontinuous (Corresponding to the
intermediate diameter portion 15 of 10). That is, the diaphragm 10 of the first embodiment can
be regarded as n being infinite in the diaphragm 100 of the second embodiment.
[0059]
Example Next, the external shape of the diaphragm 10 of the first embodiment described above
is a regular pentagon, and this is expanded and arranged as shown in FIG. The process of
manufacturing the electroacoustic transducer using the diaphragm 200 having a regular
dodecahedron and the electroacoustic transducer 150 using the diaphragm 200 according to the
embodiment of the manufacturing method of the present invention will be described in detail. .
Further, in this embodiment, a diaphragm 201 having a substantially regular dodecahedron using
the diaphragm 100 of the second embodiment in place of the diaphragm 10 of the first
embodiment as the diaphragm and an electro-acoustic transducer are used. It will be described in
detail as a modification. The diaphragms 200 and 201 have a form in which the flat plate-like
diaphragms 10 and 100 are respectively combined as described above, and in the following
description, this form corresponds to the form of the hollow sphere surface. It shall be regarded
as a spherical shell diaphragm (spherical shell diaphragm) for convenience, including the aspect
of a regular dodecahedron.
[0060]
FIG. 11 shows an appearance of the electroacoustic transducer 150 manufactured in the
12-05-2019
20
embodiment of the present invention. The electro-acoustic transducer 150 may be referred to as
a sphere speaker or the like in view of its form, or a breathing sphere speaker or the like in view
of the vibration mode of the diaphragm 200.
[0061]
The electroacoustic transducer 150 includes a substantially spherical shell-shaped diaphragm
200 (hereinafter, also referred to as a spherical shell diaphragm 200 to distinguish it from a
single diaphragm as described above), the spherical shell diaphragm 200. And a drive unit 232
(not shown) having a magnetic circuit 234 (not shown) for driving the spherical shell diaphragm
200 in the radial direction, and the outer side of the spherical shell diaphragm 200 supporting
the drive unit 232. And a supporting leg 103 extending to the
[0062]
The electroacoustic transducer 150 includes a substantially spherical shell-shaped diaphragm
200 (hereinafter, also referred to as a spherical shell diaphragm 200 to distinguish it from a
single diaphragm as described above), the spherical shell diaphragm 200. And a drive portion
232 (not shown) having a magnetic circuit 234 for driving the spherical shell diaphragm 200 in
the radial direction, and a support for supporting the drive portion 232 and extending to the
outside of the spherical shell diaphragm 200 And a leg 103.
[0063]
Here, the spherical shell diaphragm 200 will be described with reference to FIG. 13. As described
above, in the spherical shell diaphragm 200, eleven diaphragms 10 each having an outer shape
of a regular pentagon are prepared. Ten sides are butted and joined together by a flexible edge
102 to form 11 sides of a regular dodecahedron.
In other words, the surface of a sphere having a predetermined diameter is approximately
divided into 12 regular pentagons, and the diaphragm 10 is applied to each of 11 of the 12
regular pentagons divided. is there.
Therefore, as the diaphragm 200, there is no one surface of the regular dodecahedron, which is
an opening. Hereinafter, the individual diaphragms 10 are also referred to as segments 101.
12-05-2019
21
[0064]
Referring back to FIG. 14, one of the 12 surfaces (the surface shown by the arrow in FIG. 14),
which is the opening, is a plate (shown in FIG. 14) having a hole through which the support leg
103 is inserted. Closed). This plate is joined to the spherical shell diaphragm 200 via the flexible
edge 102. Further, the support leg 103 inserted into the hole is also fixed in the hole. An
installation pedestal (not shown) is attached to one end 103 a of the support leg 103, and the
electro-acoustic transducer 150 itself can be installed on a floor surface or suspended from a
ceiling.
[0065]
The electro-acoustic transducer 150 is provided with a total of eleven driving parts 232, one for
each of the diaphragms 10, as apparent from FIG. 15 showing the state where the spherical shell
diaphragm 200 is removed.
[0066]
Next, the configuration of the drive unit 232 and the like corresponding to one segment 101
which is each diaphragm 10 will be described with reference to FIG.
In FIG. 16, the housing 31 is removed from FIG. 3, and the end of the diaphragm 10 as the
segment 101 and the end of the diaphragm 10 adjacent to each other are connected via the edge
102 as the connecting member. Is shown. Moreover, the adjacent diaphragm 10 has described
the one part.
[0067]
One end portion of a circular tubular voice coil bobbin 221 is connected and fixed to the
diaphragm 10 on the surface opposite to the projecting surface of the inner diameter portion 13.
In this state, the central axis O of the outer shape of the moving plate 10 and the tube axis Ob of
the voice coil bobbin 221 coincide with each other. The voice coil 222 is wound around the outer
peripheral surface of the voice coil bobbin 221 on the other end side. Outside the voice coil 222,
a cup-shaped yoke 223 is disposed so that the inner peripheral surface of the annular wall 223b
faces the outer peripheral surface of the voice coil 222 with a gap. Further, inside the voice coil
12-05-2019
22
bobbin 221, a cylindrical pole piece 225 coupled to the magnet 224 is disposed so as to have a
gap with the inner circumferential surface thereof. In addition, a ring-shaped frame 235 is fixed
to the yoke 223. The voice coil bobbin 221 and the frame 235 are connected by two dampers
233 having elasticity, and the voice coil bobbin 221 is elastically supported by the damper 233
so as to be movable in a direction parallel to the central axis O with respect to the frame 235 It is
done. The magnet 224 is fixed to the bottom 223 a of the yoke 223, and the yoke 223 is fixed to
the mounting surface 132 a of the support base 132. As this drive part 232, what is used in
order to drive the diaphragm which has an external shape centering on the tube axis Ob of the
voice coil bobbin 221 can be diverted as it is.
[0068]
As shown in FIG. 17, a total of 11 supporting bases 132 are attached to each of 11 of the 12
sides of the base 130 assembled into a substantially regular dodecahedron by the base frame
131. . Although not shown, the support legs 103 described above are fixed to the remaining one
surface of the base 130. Further, as shown in FIG. 16, in the mounting surface portion 132 a of
the support base 132, as described above, the bottom surface of the yoke 223 is a tube axis
which is a central axis of the central axis O12 of each surface of the regular dodecahedron and
the drive portion 232. It is fixed so that it matches Ob.
[0069]
Accordingly, the electro-acoustic transducer 150 is fixed to the base 130 such that the mounting
surface portion 132a is positioned corresponding to the base 130 whose outer shape is a
substantially regular dodecahedron and the eleventh side of the regular dodecahedron. Eleven
support bases 132 and eleven drive parts 232 fixed to the mounting surface parts 132a of these
support bases 132 are provided, and the voice coil bobbin 221 of each drive part 232 has a
regular pentagonal outer shape The diaphragm 10 is assembled by connecting eleven of the
diaphragms 10 corresponding to the eleven faces of a regular dodecahedron, and is connected to
each diaphragm 10 of the spherical shell diaphragm 200 as a substantially spherical shell.
Therefore, the electroacoustic transducer 150 is supported such that the spherical shell
diaphragm 200 is aligned with the tube axis Ob by the voice coil bobbins 221 of the drive units
232 for the central axis O of each diaphragm 10, It is driven to vibrate in the normal direction of
the sphere circumscribing the regular dodecahedron, and emits sound.
[0070]
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23
As a result, it is possible to emit the sound in almost all directions while extremely reducing the
sound pressure difference caused by the difference in emitting angle. Therefore, when the
electro-acoustic transducer 150 is disposed, for example, in a hole or the like to emit sound, a
sound field excellent in sense of reality is formed regardless of the listening position. In addition,
when listening to the sound emitted at a position close to the electroacoustic transducer 150,
even if the listening position moves, the localization of the sound moves naturally without
moving extremely, so a good sense of reality is obtained. can get.
[0071]
When the diaphragm 10 described above is used as an individual diaphragm, the shape of the
diaphragm 10 is such that the outer diameter portion 14 and the inner diameter portion 13 have
a central axis O coaxial with and coaxial with the central axis O2 When the intermediate diameter
portion 15 is provided, generation of symmetrical standing waves with respect to the central axis
O can be suppressed, and peaks and dips in the frequency-sound pressure characteristic can be
flattened. In addition, the shape of the diaphragm 10 is around the central axis O2 in which the
cross-sectional shape orthogonal to the central axis O in the inclined portion 12 has a central axis
O in which the outer diameter portion 14 and the inner diameter portion 13 are coaxial With the
eccentric surface portion having a rotationally symmetric shape, generation of symmetrical
standing waves with respect to the central axis O can be suppressed, and peaks and dips in the
frequency-sound pressure characteristics can be flattened.
[0072]
Further, if diaphragm 10R which is a modification of diaphragm 10 as shown in FIG. 10 is used
as each diaphragm, it has a curved surface such that inclined part outer side surface 12b follows
a part of spherical surface CF. Since the spherical shell diaphragm 200 has an outer appearance
shape closer to a sphere, the appearance quality as a spherical speaker is improved.
[0073]
Next, as a modification of this diaphragm, using the diaphragm 100 (see FIG. 11B and FIG. 15A)
instead of the diaphragm 10, the eleven diaphragms 100 are inserted via the edge 102. FIG. 15B
shows the appearance of a spherical shell diaphragm 201 which is formed into a substantially
spherical shell by joining each side so as to be in contact with each other.
12-05-2019
24
The support leg 103 is omitted in this figure.
[0074]
As shown in FIGS. 18A and 18B, the outer shape of each diaphragm 100 is a regular pentagon
having apexes T1 to T5. Further, in FIG. 18A, the figure C2 connecting the apexes TP1 to TP5 is a
circle, and its center O3 is shifted from the main center G0 of the regular pentagon by a distance
α in the direction toward the apex T1. There is. Further, as can be seen from FIG. 18B, the main
center G0 and the tops TP1 to TP5 protrude outward with respect to the reference plane P0 set
including the vertices T1 to T5, and the amount of projection is the main center G0 is formed to
be the largest. Further, the voice coil bobbin 221 joined to the diaphragm 100 is the voice coil
bobbin 221 described with reference to FIG. 12 and includes the position corresponding to at
least each of the top portions TP1 to TP5 of the diaphragm 100, the surface on the drive portion
232 side. Adhesively fixed to
[0075]
When the spherical shell diaphragm 201 of this modification is used, each diaphragm 100 has
the center GO of the outer shape as the top TP0 projecting in one direction with respect to the
reference plane P0 including the apexes T1 to T5 and Between the center G0 and the outer shape
(outer diameter portion 14), a plurality of protruding top portions TP1 to TP5 are provided and
the top portions TP1 to TP5 are connected to form a center O3 of the figure C2 from the center
G0 of the outer diameter portion 14 Since the diaphragm surface is formed to be decentered with
respect to the direction orthogonal to the reference plane P0 which is the sound emission
direction while being decentered, dips and peaks in the frequency-sound pressure characteristics
are flattened. In addition, the sound pressure difference due to the difference in the angle
between the center G0 and the axis perpendicular to the reference plane P0 (the central axis of
the diaphragm 100) decreases, and a characteristic close to no directivity can be obtained.
[0076]
Further, as described in detail in the description of the diaphragm 100, the shape of the
diaphragm 100 is made to project the center G0 most with respect to the reference plane P0, and
the projecting center G0, the plurality of apexes TP1 to TP5, and each vertex of the outer shape If
T1 to T5 are formed to be included in a spherical surface with a constant curvature, the sound
pressure difference due to the difference in the angle made with respect to the central axis O of
the diaphragm 100 becomes small, which is preferable in order to obtain nondirectionality.
12-05-2019
25
[0077]
In addition, if the constant curvature is made to coincide with the curvature of the surface of the
spherical shell diaphragm 201, the entire shape of the spherical shell diaphragm 201 becomes
closer to a true sphere. Since the sound pressure difference due to the difference in the angle
formed is smaller and the directivity characteristic is smoother, it is more preferable because an
effect that the directivity characteristic as the spherical shell diaphragm 201 further approaches
non-directivity is obtained.
[0078]
When the spherical shell diaphragms 200 and 201 are formed using the diaphragms 10 and 10R
or the diaphragm 100 described above, if the eccentric direction of the diaphragms 10 and 100
is set to a predetermined direction, the electroacoustic transducer 150 is formed. Is preferably
installed on a floor surface, for example, since the sound pressure fluctuation is reduced when
the listening position to that position is particularly changed in the latitudinal direction (vertical
direction).
The eccentric direction will be described with reference to FIG.
[0079]
In FIG. 19, this electro-acoustic transducer 150 is installed so that the diaphragm on the top
surface opposite to the plate of the bottom surface 10B to which the support legs 103 are
attached is the diaphragm 10T, and this is parallel to the floor surface FL. It is a front view which
shows a state.
This is an example of installation.
The diaphragm in FIG. 19 is a spherical shell diaphragm 200 using the diaphragm 10 of the first
embodiment. In this state, the side where the five diaphragms 10-1 to 10-5 connected to the
diaphragm 10T on the top surface and the five diaphragms 10-6 to 10-10 connected to the plate
on the bottom surface 10B are joined is 19 is a junction of the boundary which divides the
12-05-2019
26
spherical shell diaphragm 200 into upper and lower parts in FIG. This line EQ is shown by a thick
broken line in FIG.
[0080]
Assuming that the spherical shell diaphragm 200 is the earth, the line EQ will be hereinafter
referred to as the equator EQ, the top side of the equator EQ as the northern hemisphere, and the
bottom side as the southern hemisphere. The preferable eccentric direction of the diaphragms 10
and 100 is a direction toward the apex on the equator EQ for the diaphragms 10-1 to 10-5 in the
northern hemisphere and the diaphragms 10-6 to 10-10 in the southern hemisphere. When the
eccentric direction is set as described above, it is preferable that the sound pressure fluctuation is
reduced when the listening position changes in the latitude direction (vertical direction in FIG.
19).
[0081]
Furthermore, it is more preferable that the eccentric direction of the diaphragms 10-1 to 10-5 in
the northern hemisphere and the eccentric direction of the diaphragms 106 to 10-10 in the
southern hemisphere be opposite in the circumferential direction as shown in FIG. Specifically, as
shown by the arrows in FIG. 19, when viewed from the top, the diaphragms 10-1 to 10-5 in the
northern hemisphere are decentered clockwise toward the apex on the equator EQ, and the
southern hemisphere The diaphragms 10-6 to 10-10 may be decentered in the counterclockwise
direction toward the top of the line EQ. The clockwise rotation and the counterclockwise rotation
may be reversed. As described above, when the diaphragms on both sides connected by the line
EQ, which is a junction that divides the spherical shell diaphragm 200 into two, are decentered in
mutually different circumferential directions, the listening position changes in the latitude
direction The sound pressure fluctuation of is averaged and the fluctuation is further reduced.
[0082]
This line EQ is not limited to one set parallel to the floor surface FL. Depending on the listening
position, the direction of the line EQ can be appropriately set so as to be the optimum directivity
characteristic at the listening position. Further, since the support legs 103 may extend in any
direction, the extension direction of the support legs 103 does not restrict the setting direction of
the line EQ.
12-05-2019
27
[0083]
On the other hand, when the listening position is assumed, it is preferable that the eccentric
direction of the diaphragm 10T on the top surface is set as the direction approaching the
listening position. In this way, the sound pressure fluctuation when the listening position moves
up and down at that position is further reduced.
[0084]
By the way, when the edge 102 is made of a particularly soft material, or when the spherical
shell diaphragms 200 and 201 are relatively large, the shape of the spherical shell diaphragms
200 and 201 is not distorted by the weight of the diaphragm itself. A support 236 may connect
between the edge 102 and the base 130 as shown by a two-dot chain line in FIG. The support
236 additionally supports the ball shell diaphragms 200 and 201 on the voice coil bobbin 221 to
support them, and has elasticity such that the shape of the diaphragm is not deformed and the
vibration is not affected. It is formed of the material which it has.
[0085]
Next, a process of manufacturing the above-described electroacoustic transducer 150 will be
described mainly using FIG. In this example, an example having a substantially regular
dodecahedron spherical shell diaphragm 200 formed by combining a plurality of diaphragms 10
will be described, but the diaphragms 10R and 100 may be used instead of the diaphragms 10,
and the same manufacture is possible. can do.
[0086]
(Step 1) First, a flat plate or sheet diaphragm material is subjected to press processing, drawing
processing, or the like to form the diaphragm 10 corresponding to each segment 101. As this
diaphragm material, as described above, a sheet of paper, metal, resin, ceramic or wood can be
used. Each sheet may be a stack of one or more sheets.
12-05-2019
28
[0087]
(Step 2) Next, 11 segments 101 are deployed and arranged on a plane as shown in FIG. 13, and
in this state, the sides of individual segments 101 that can be joined are butted, and respectively
through flexible edges 102. Joint. For example, a rubber material or resin material can be used
for the edge, and a known adhesive can be used for bonding.
[0088]
In this example, two segments 101 are continuously joined to each side of one center segment
101-C as a center. Specifically, in FIG. 13, the five segments 101-1 to 101-5 adjacent to one
central segment 101-C are joined, and the segments 101-1 to 101-5 are further segmented. Join
6 to 101-10. In this bonding mode, two sides (shown as stripes in FIG. 13) apart from the
segment 101-C become a line EQ.
[0089]
Further, when developing on a plane, each segment 101 is directed such that the eccentric
direction of the intermediate diameter portion 15 of each segment 101 is directed to the vertex
on the line EQ after combination (arrow direction in FIG. Deploy. When the arrangement of FIG.
13 corresponds to FIG. 19, for example, the segment 101-C becomes the diaphragm 10T on the
top surface, and the segments 101-1 to 101-5 are diaphragms 10-1 to 10-5 on the northern
hemisphere side, The segments 101-6 to 101-10 become the diaphragms 10-6 to 10-10 on the
southern hemisphere side.
[0090]
(Step 3) On the other hand, as shown in FIG. 17, the support base 132 is fixed to each of 11 sides
of the base 130 which is formed in a substantially regular dodecahedron shape by combining the
base frames 131 in advance. Then, the bottom surface 223a of the yoke 223 is fixed to the
mounting surface portion 132a of the support base 132 with an adhesive or the like. A magnet
224 or the like to which the pole piece 225 is fixed in advance is attached to the yoke 223 to
form a drive portion 232 in advance.
12-05-2019
29
[0091]
(Step 4) Align the movable part such as the voice coil bobbin 221 or the like on which the voice
coil 222 is wound with the fixed part such as the yoke 223 and the magnet 224 so that both are
at predetermined opposing positions as shown in FIG. , Attached through the damper 233.
Bonding in this attachment can also be performed using an adhesive. The assembled assembly
202 is shown in FIG.
[0092]
(Step 5) Next, the eleven segments 101 partially joined in (Step 2) are put on the assembly 202
to which the eleven driving parts 232 are attached. At that time, each segment 101 is put on to
correspond to each voice coil bobbin 221 attached in (Step 4). Then, the end of the voice coil
bobbin 221 is fixed to the inner surface of each segment 101 by an adhesive so that the central
axis O of each segment 101 matches the tube axis Ob of the voice coil bobbin 221.
[0093]
(Step 6) In this state, since the sides not joined in (Step 2) in each segment 101 are positioned so
as to naturally but substantially abut each other, the adhesive agent is applied via the flexible
edge 102. The two pieces are joined to form a spherical shell diaphragm 200 having a
substantially spherical shell shape.
[0094]
(Step 7) The support leg 103 is fixed to the base 130, a plate closing the opening of the spherical
shell diaphragm 200 is disposed at the opening, and the plate is joined to the spherical shell
diaphragm 200 and the support leg 103.
The attachment between the support leg 103 and the base 130 is not limited to the end, and may
be performed in advance between any other steps. The electro-acoustic transducer 150 is
manufactured by the above process.
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[0095]
According to this manufacturing process, in (Step 2), each side of bondable segments 101 is
bonded in advance in a state in which each segment 101 is developed on a plane, and in the
subsequent (Step 5) Since the respective sides are joined to each other, the alignment of the
opposing parts when assembling the segment 101 into a spherical shell shape is simplified, and
the spherical shell diaphragm 200 can be easily assembled.
[0096]
In each segment 101, since the central axis O of the polygon, which is the outer shape, and the
central axis Ob of the drive of the drive unit 232 (the tube axis of the voice coil bobbin 221)
coincide with each other, A general purpose drive unit 232 having a rotationally symmetric
shape can be used.
Further, the alignment between the movable part side and the fixed part side in the assembling
operation can be easily and accurately performed.
[0097]
The embodiments of the present invention are not limited to the above-described procedure, and
may be modified within the scope of the present invention. For example, in the case where the
spherical shell diaphragm 201 is formed using the diaphragm 100 whose outer shape is a
regular n-gon, when n is 4 or 5, the lengths and directions of the respective sides conform to
each other. It can be connected to a polyhedron. In addition, when n is 6 or more, a regular
polyhedron can not be formed, so when it is formed into a spherical shell, a gap is generated, but
this gap is closed by a flexible connecting member to connect them A spherical shell diaphragm
can be used. The edge 102, which is a connecting member for connecting the diaphragms 10,
10R, and 100, is bonded to each of the diaphragms 100, 10R, and 100 using an adhesive.
However, the invention is not limited to the use of the edge 102, The diaphragms 100, 10R, and
100 may be bonded to each other via an adhesive. In this case, it goes without saying that this
adhesive serves as a connecting member.
[0098]
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31
It is a schematic perspective view which shows the 1st example of a form applied to this
invention. It is the top view and sectional drawing which show the 1st example of a form applied
to this invention. It is sectional drawing which shows the electroacoustic transducer using the 1st
example of a diaphragm applied to this invention. It is sectional drawing which shows the other
example of the electroacoustic transducer using the 1st example of a diaphragm applied to this
invention. It is a schematic diagram for demonstrating standing wave distribution in the
conventional diaphragm. It is a schematic diagram for demonstrating standing wave distribution
of the diaphragm applied to this invention. It is a graph which shows the frequency-sound
pressure characteristic according to the amount of eccentricity of a diaphragm. It is a typical
sectional view for explaining the diaphragm shape applied to the present invention. It is a typical
sectional view for explaining the shape of the 1st example of a diaphragm applied to the present
invention. It is the top view and sectional drawing which show the modification of the 1st form
example of the diaphragm applied to this invention. It is a front view for comparing and
explaining the conventional diaphragm and the 2nd embodiment of the diaphragm applied to
this invention. It is an outline view showing the electroacoustic transducer manufactured by the
example concerning the present invention. It is a developed view of a diaphragm for explaining
an example concerning the present invention. It is a fragmentary sectional view for explaining
the electroacoustic transducer manufactured by the example concerning the present invention. It
is a perspective view for demonstrating the structure of the electroacoustic transducer
manufactured by the Example which concerns on this invention. It is a fragmentary sectional
view for explaining the structure of the electroacoustic transducer manufactured by the example
concerning the present invention. It is another perspective view for demonstrating the
electroacoustic transducer manufactured by the Example which concerns on this invention. It is
the front view and perspective view for demonstrating the other form of the diaphragm used for
the electroacoustic transducer manufactured by the Example which concerns on this invention. It
is a front view for demonstrating the electroacoustic transducer manufactured by the Example
which concerns on this invention.
Explanation of sign
[0099]
10, 10R, 100 diaphragm 11 central portion 12 inclined portion 12a inclined portion inner side
surface 12b inclined portion outer side surface 13 inner diameter portion 14 outer diameter
portion 15 intermediate diameter portion 21, 221 voice coil bobbin 21a cylindrical portion 21b
joint portion 22, 222 voice coil 22a Lead wire 23, 223 yoke 23a bottom 23b annular wall 24,
224 magnet 25, 225 pole piece 30 edge 31 housing 31 a hole 31 b annular frame 32, 232
driving unit 33 damper 34, 234 magnetic circuit 50, 150 electroacoustic transducer 200 , 201
ball shell diaphragm 10a, 100a diaphragm 101 segment 102 edge 103 support leg 130 base
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131 frame for base 132 support base 132a mounting surface 202 assembly 235 frame 236
support D1 to D3 diameter L floor surface G0 main center (center) G1 to Gn center of gravity α
(of eccentricity) distance O3 center O4 center of curvature O, O2, O5, O12 center axis Ob (voice
coil bobbin) tube axis P0 reference plane 蛆 P13 including inner diameter Plane T1 to Tn vertex
TP1 to TPn top R, R1 curvature α distance (amount of eccentricity)
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