JP2005123893A - Electroacoustic transducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sound source (spherical wave sound field) close to a respiratory sphere and to increase output sound pressure. <P>SOLUTION: A diaphragm 100 is constituted by dividing the surface of a sphere into twelve pentagonal segments 101 and bonding the boundary of each segment through a flexible edge 102 wherein each segment is driven independently by a magnetic circuit. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an electroacoustic transducer having a substantially spherical shape, a so-called spherical speaker.

  The present applicant has previously proposed a spherical speaker as shown in FIG. In FIG. 10, the spherical speaker S is composed of two hemispheres 1 and these two hemispheres 1 are assembled together. Each hemisphere 1 includes 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 have.

  The base member 2 is made of a resin such as polycarbonate, and one surface is provided with a positioning pin 2b protruding at a position opposed to 180 degrees, and the other surface of the base member 2 is joined to another hemisphere. It is comprised as the 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 chrome-plated metal such as copper or brass, and has a hemispherical hemispherical portion 3a, and an outer ring of the hemispherical portion 3a that extends in the radial direction. Part 3b. The flange portion 3b is provided with a positioning hole (not shown) and a screw insertion hole (not shown), and the positioning pin 2b of the base member 2 is inserted into the positioning hole. Thus, the inner electrode 3 is positioned and arranged on the base member 2 such that the center of the hemispherical portion 3a coincides with the center of the base member 2.

  The diaphragm 4 is slightly larger than the inner electrode plate 3, and similarly, a hemispherical hemispherical portion 4 a and an annular flange 4 b that extends radially around the outer periphery of the hemispherical portion 4 a. It consists of and. Similarly, the flange 4b is provided with a positioning hole (not shown) and a screw insertion hole (not shown) (not shown), and the positioning pin 2b of the base member 2 is inserted into the positioning hole. ing. An annular spacer 7 is disposed between the flange 4 b of the diaphragm 4 and the flange 3 b of the inner electrode plate 3. The spacer 7 is appropriately composed of one or two or more members depending on the interval to be secured. The cross-sectional configuration of the diaphragm 4 includes a resin base layer formed of a resin that can expand and contract in the radial direction, a conductive layer formed by vapor-depositing a conductive metal on one surface of the resin base layer, It is constituted by laminating a strength reinforcing layer disposed on the other surface of the resin base layer.

  The outer electrode plate 5 is slightly larger than the diaphragm 4 and is formed of the same material as that of the inner electrode plate 3. Similarly, the outer electrode plate 5 has a hemispherical hemispherical portion 5a and an outer periphery of the hemispherical portion 5a, and in the radial direction. It is comprised from the annular | circular shaped collar part 5b extended. Similarly, the flange portion 5b is provided with a positioning hole (not shown) and a screw insertion hole (not shown), and the positioning pin 2b of the base member 2 is inserted into the positioning hole. An annular spacer 8 is disposed between the flange portion 5 b of the outer electrode plate 5 and the flange portion 4 b of the diaphragm 4. The spacer 8 is composed of one or more members as appropriate depending on the interval to be secured.

  The cover 6 is formed of, for example, urethane resin with good air flow, and is larger than the outer electrode plate 5, and extends in the radial direction on the outer periphery of the hemispherical hemispherical portion 6 a and the hemispherical portion 6 a. It is comprised from the annular | circular shaped collar part 6b provided. 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. Further, a screw insertion hole (not shown) is provided in the flange portion 6 b of the cover 6. The diaphragm 4, the inner electrode plate 3, and the outer electrode plate 5 are configured to be able to supply power via electrode portions (not shown) of spacers 7 and 8, respectively.

  Two hemispherical bodies 1 configured as described above are provided, and the two hemispherical bodies 1 and 1 are fixed by screw fastening using a screw insertion hole in a state where the joint surfaces 2a are joined to each other. A spherical speaker S shown in FIG.

  In the above configuration, when a bias voltage is applied to the diaphragm 4 of each hemisphere 1, a capacitor is formed between the diaphragm 4, the inner electrode plate 3, and the outer electrode plate 5 of each hemisphere 1 by this bias voltage. A situation is created where an electrostatic effect occurs. In this state, when a driving current that is an audio signal is supplied to each hemisphere 1, the diaphragm 4 of each hemisphere 1 that can expand and contract in accordance with this driving current is synchronously fluctuated in the radial direction to perform respiratory motion. As a result, a spherical wave sound field is realized.

  However, in the above-described spherical speaker (electrostatic electroacoustic transducer) S, since the variation in the radial direction is limited at the position of the flange 4b of the diaphragm 4, a sound source (spherical wave sound field) that is almost a perfect breathing sphere. ) Cannot be realized.

Therefore, as shown in FIG. 8 and FIG. 9, the following Patent Document 2 has been made to solve the above-described problem, and an electroacoustic conversion capable of realizing a sound source (spherical wave sound field) close to a respiratory sphere. It was proposed to provide a vessel. This electroacoustic transducer includes a substantially spherical vibrating body 10 having a conductive layer, and a substantially spherical electrode plate disposed at an interval between at least one of the inner circumferential side and the outer circumferential side of the vibrating body 10. 11, 12, a sphere support structure 13 that supports the vibrating body 10 and the electrode plates 11, 12 at a distance and supplies a voltage to the vibrating body 10 and the electrode plates 11, 12, and a sphere support structure The sphere support structure 13 supports only two vertex portions that are substantially point-symmetric about the center point of the substantially spherical shape of the vibrating body 10.
Japanese Unexamined Patent Publication No. 2000-78686 (FIG. 1) JP 2001-95088 A (FIG. 2)

  As shown in detail in FIG. 9, each of the vibrating bodies 10 includes a triangle formed by a line segment drawn from the center of gravity of an n-gon (n: an integer of 4 or more) and (n + 1) to each vertex, from the center of gravity to each side. A combination of shapes folded into a V shape by a drawn vertical line, where the center of gravity of each polygon is arranged at a position protruding in the direction of increasing radius, and the direction of the foot of the vertical line drawn on each side decreases in radius Each polygon that is folded at the same time and is constructed so that the legs of both perpendicular lines drawn on the common side of adjacent polygons are continuous and located at two vertex positions of the vibrator 10. On the other hand, it is supported by a sphere support structure 13. The vibrating body 10 is configured as a three-divided member in the vertical direction before assembly, and a shaft insertion hole is formed at the apex portion of each divided member.

  The inner electrode plate 11 and the outer electrode plate 12 are made of a metal chrome-plated on copper, brass or the like, and are each made up of two upper and lower hemispheres 11a and 12a. The two hemispheres 11a and 12a are assembled together. And configured in a spherical shape. A large number of air circulation holes (not shown) are formed in the hemispheres 11a and 12a, which are the divided members, and shaft insertion holes are formed at the apexes of the hemispheres 11a and 12a.

  The spherical support structure 13 is arranged in the inner space of the inner electrode plate 11 and is slightly inclined with respect to the vertical direction, and the central support member is arranged in the inner space of the inner electrode plate 11. A pair of longitudes that are fixed to the inner electrode support member 21 that supports the inner electrode plate 11 and the outer electrode plate 12 and is fixed to the upper end of the center support member 20 and the pedestal 14 at both ends. Support members 22, 22, outer electrode support member 23 fixed to each longitude support member 22 and fixing outer electrode plate 12, and vibrating body 10 and inner electrode plate 11 at the upper and lower ends of center support member 20. In addition to supporting the outer electrode plate 12 and the outer electrode plate 12, the upper electrode side support portion 24 and the lower electrode side support portion 25 for supplying voltage are configured. That is, the vibrating body 10, the inner electrode plate 11, and the outer electrode plate 12 are supported by two vertex portions that are substantially point-symmetric about the spherical center point. The vibrating body 10 itself is supported only at the two apex portions, and the other portions are configured not to be restricted by other members.

  The center support member 20 is formed in a rod shape, and an electric wire insertion hole 20a is formed therein, and a voltage supply electric wire (not shown) is guided through the electric wire insertion hole 20a. The lower end of the center support member 20 is fixed to the pedestal body 14 by being press-fitted into the electric wire insertion hole 42 a of the pedestal body 14.

  The inner electrode support member 21 is formed in a disc shape, and a rod insertion hole (not shown) is formed at the center thereof. The center support member 20 is inserted into the rod insertion hole, and is fixed to the center support member 20 by being sandwiched between a step of the center support member 20 and a retaining member (not shown). The pair of longitude support members 22, 22 has a substantially arc shape, and the flanges at both ends of each longitude support member 22 will be described later with screws (not shown) inserted into screw holes (not shown). It is fastened to a pole cap member (not shown) and the pedestal 14 respectively.

  The outer electrode support member 23 has a ring shape, and recesses are respectively formed at positions facing this 180 °. As described above, the longitude support member 22 is fitted in the recess. In addition, electrode support grooves are formed in the inner peripheral edge portions of the upper and lower surfaces of the outer electrode support member 23, and fixed by inserting the circular peripheral edge portion of each hemisphere 12a of the outer electrode plate 12 into the electrode support grooves on both sides. Has been.

  As shown in FIG. 8, the upper pole support 24 includes an inner electrode voltage supply member having a substantially flat ring shape, a plurality of spacers, a diaphragm voltage supply member, an outer electrode voltage supply member, and a pole cap. The member 38 is pressed into the upper end portion of the center support member 20 in this order. The inner electrode plate 11 is supported between the voltage supply member and the spacer, the vibrating body 10 is interposed between the diaphragm voltage supply member, and the outer electrode plate 12 is interposed between the spacer and the outer electrode voltage supply member. Has been. The lower pole side support portion 25 has the same configuration and is press-fitted into the lower end portion of the center support member 20. Each diaphragm voltage supply member has a radial wave shape corresponding to the polygonal shape of the vibrating body 10.

  As shown in FIG. 8, the electrode voltage supply member and the diaphragm voltage supply member on the upper and lower pole sides are wired so that a voltage is supplied, and these wires are connected to the wire insertion holes 40a and 42a of the base body 14 and the center support. It is guided through the wire insertion hole 20 a of the member 20.

Next, the configuration of the vibrating body 10 will be described. As described above, the vibrating body 10 is configured as a three-piece member in the vertical direction at the stage before assembling, but the three-divided member is joined in the assembling process. (A) has a shape as shown in FIG. 9A (in FIG. 9A, each joint portion (divided position) of the three-divided member constituting the vibrating body 10 is indicated by a bold line. The joint part of the split member is hardly understood). That is, as shown in FIG. 9B, each vertex t1, t2 from the center of gravity O ₁ , O ₂ of a dotted pentagon (n-gon, where n is an integer of 4 or more) and a dotted hexagon (n + 1 square). Each triangle formed by the line segments L1 and L2 drawn to is a combination of shapes folded in a V shape by perpendicular lines v1 and v2 drawn from the centroids O ₁ and O ₂ to the respective sides m1 and m2. The center of gravity O ₁ , O _{2 of the} polygon is arranged at a position protruding in the direction in which the radius increases, and the legs of the vertical lines v1, v2 drawn on the sides m1, m2 are folded in the direction in which the radius decreases, and The legs of both perpendicular lines v1 and v2 drawn on the common sides m1 and m2 of adjacent polygons are continuous. This structure can be easily displaced about the legs of the vertical lines v1 and v2 when an external force acts in the radial direction. The intersection N of the legs of the vertical lines v1 and v2 is the point of maximum amplitude.

  The cross-sectional configuration of the vibrating body 10 includes a resin base layer formed of a resin that can expand and contract in the radial direction, a conductive layer formed by depositing a conductive metal on one surface of the resin base layer, A strength reinforcing layer disposed on the other surface of the resin base layer and a conductive layer formed by vapor-depositing an isoelectric metal on one surface of the strength reinforcing layer are laminated. In this embodiment, the strength reinforcing layer is made of a foamed polypropylene sheet (foaming material), which is a porous layer. However, the strength reinforcing layer may be a member that can reinforce the strength without inhibiting the expansion and contraction of the resin base layer in the radial direction. That's fine.

  In the above configuration, when a DC bias voltage of 4000 V or more (for example, 4300 V) is applied to the vibrating body 10, capacitors are formed between the vibrating body 10 and the inner electrode plate 11 and the outer electrode plate 12 by the DC bias voltage, A state in which an electrostatic effect occurs is configured. In this state, when a drive current that is an audio signal is supplied, the vibrating body 10 receives the external force in the radial direction in synchronization with the drive current, thereby performing the respiratory motion as described above.

  However, according to Patent Document 2, a sound source close to a respiratory sphere can be realized, but the distance between the electrodes 11 and 12 arranged on the inner side and the outer side of the vibrating body 10 inevitably increases due to the restriction of the shape, The driving force sufficient to withstand practical use could not be obtained, and the problem that the output sound pressure could not be increased remained.

  Accordingly, the present invention has been made to solve the above-described problems, and can achieve a sound source (spherical wave sound field) close to a respiratory sphere and can increase an output sound pressure. The purpose is to provide.

In order to achieve the above object, the invention of claim 1 is a substantially spherical diaphragm in which the surface of a substantially spherical body is divided into a plurality of polygonal segments and the boundaries of each segment are connected by an elastic material;
A plurality of voice coils respectively attached to an inner central portion of each of the plurality of segments;
A plurality of magnetic circuit structures including magnets disposed respectively facing each of the plurality of voice coils;
A plurality of supports each supporting each of the plurality of magnetic circuit structures;
A plurality of suspensions respectively coupled to each of the plurality of supports so that each of the plurality of voice coils can vibrate in the coil axis direction;
The configuration was provided.
With this configuration, since the surface of the substantially spherical body is divided into a plurality of polygonal segments and each segment is driven independently, a sound source (spherical wave sound field) close to a breathing sphere can be realized and the output sound pressure can be increased. can do. In addition, the electroacoustic transducer having such a configuration can realize a spherical wave sound field that is closer to an ideal as the diameter of the substantially spherical shape is smaller.

The invention according to claim 2 is the electroacoustic transducer according to claim 1, wherein a plurality of the suspensions are provided for each voice coil.
This configuration improves the center support capability of the voice coil, so in an electroacoustic transducer having a structure in which the outer periphery of the diaphragm is not fixed to a member such as a frame, the axial movement of the voice coil Is realized more accurately, and the input resistance characteristics are improved.

According to a third aspect of the present invention, in the electroacoustic transducer according to the first or second aspect, the substantially spherical diaphragm is arranged at each vertex from the center of gravity of an n-gon (n: integer of 4 or more) and an (n + 1) -gon. Each triangle formed by a line segment drawn to the right is a combination of shapes folded into a V shape by a perpendicular drawn from the center of gravity to each side, and the position where the center of gravity of each polygon protrudes in the direction of increasing radius The vertical legs drawn on each side are folded in the direction of decreasing radius, and both vertical legs drawn on a common side of adjacent polygons are continuous. And
This structure is divided into the plurality of polygonal segments, and the boundaries of the segments are connected by the elastic material.
With this configuration, it is possible to realize a sound source (spherical wave sound field) that vibrates in the axial direction of the voice coil and is close to a breathing sphere, and a large sound output can be obtained because the amplitude can be increased.

  According to the present invention, since the surface of the substantially spherical body is divided into a plurality of polygonal segments and each segment is driven independently, it is possible to realize a sound source (spherical wave sound field) close to a respiratory sphere and output sound pressure Can be increased.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a structural view of an embodiment of a spherical speaker (electrostatic electroacoustic transducer) according to the present invention as seen from the front. In FIG. 1, a diaphragm 100 of a spherical speaker S is configured by dividing a substantially spherical surface into 12 pentagonal segments 101 and connecting boundaries of the segments 101 with flexible edge portions 102. Yes.

  Here, FIG. 2 shows a conventional diaphragm 10 shown in Patent Document 2, and the detailed configuration thereof is as described above. The diaphragm 100 of the present invention has the same surface shape as that of Patent Document 2, but is not a piezoelectric type but an electrodynamic type in which each segment 101 is independently driven by a magnetic circuit. The diaphragm 100 is divided into twelve pentagonal segments 101 as shown in FIG. 3, and the gaps that appear between the segments 101 as shown in FIG. A flexible edge portion 102 is used for connection.

  The inside of each segment 101 is molded into a shape convenient for joining of the drive coils so that the drive force generated by the magnetic circuit can be efficiently transmitted to each segment, or the voice coil shown in FIG. Like the structure 101a for joining, the member with the function equivalent to it is provided in the form joined.

  In the example shown in FIG. 6, the inner center of each segment 101 is coupled to a cylindrical voice coil bobbin 110, and a voice coil 111 is attached around the voice coil bobbin 110 to form a vibration system (101, 110, 111). ing. A yoke 113 is attached to the magnet-side magnetic circuit support structure 112, and a magnet 114, a pole piece 115, and a plate 116 are attached to the yoke 113 so as to face the voice coil 111. The circuit structure (113-116) is comprised. Further, segment support bases 117 and 118 are attached to the plate 116, and the first and second suspensions 119 and 120 are interposed with respect to the bases 117 and 118 so that the voice coil bobbin 110 can move in the coil axis direction. It is supported.

  The voice coil 111 that drives each segment 101 is appropriately disposed in the gap of the magnetic circuit structure (113 to 116) as shown in FIG. The magnetic circuit structures (113 to 116) are fixed to the magnet-side magnetic circuit support structure 112 disposed inside the diaphragm 100, so that the driving force is sufficiently transmitted to the vibration systems (101, 111, 111). 110).

  In the middle of the voice coil bobbin 110, suspensions 119 and 120 for holding the center are provided for the purpose of constraining the vibration system only to axial vibration, and this number is two in order to realize more reliable center holding. It is desirable to install. The suspensions 119 and 120 may have a structure in which one of them is fixed to a member provided in the segment 101 in order to fix the voice coil 111, and the axial movement is reliably performed by the structure.

  The twelve magnetic circuit structures (113 to 116) are attached to a dodecahedron structure 130 having a shape obtained by reducing the diaphragm 100 as shown in FIG. Each surface is provided with a frame 131 effective for fixing the magnetic circuit structures (113 to 116), and a support base 132 provided on the frame 131 supports the magnetic circuit on the magnet side shown in FIG. The bottom surface or the side surface of the structural structure 112 is fixed. The frame 131 is also fixed to the support column 16 as shown in FIG. 1, and the support column 16 is fixed to the support base 18.

  A pedestal 117 for fixing the suspension 119 for holding the center is disposed near the outer periphery of each surface of the magnetic circuit support structure 112 on the magnet side. After the suspension 119 is fixed, the second pedestal 118 is Arranged and the second suspension 120 is fixed thereon.

  Here, the suspension fixing pedestal 117 has a convex portion or a concave portion with sufficient accuracy so that the driving voice coil 111 is properly positioned in the gap of the magnetic circuit structure (113 to 116). In this manner, the plate 116 may be fitted into a concave portion or a convex portion that is arranged with sufficient accuracy.

  The magnetic circuit support structure 112 inside the diaphragm 100 is fixed to a rod-shaped support column 16 having an air circulation hole 16a in the center as shown in FIG. 1, and there is no abnormal vibration associated with the movement of the voice coil 111. . The support column 16 is fixed to a support base 18 having an air circulation hole (also referred to as an air hole) 18a that is also connected to the free space. By having such a structure, each segment 101 of the diaphragm 100 can translate in the axial direction, and a sound source close to a respiratory sphere as a whole can be realized.

It is the block diagram which looked at the spherical speaker (electrostatic electroacoustic transducer) which shows one embodiment of this invention from the front. It is a block diagram which shows the conventional spherical diaphragm. It is a block diagram which divided the diaphragm shown in FIG. 1 into 12 segments. It is a block diagram which shows one Embodiment of the diaphragm of this invention which connected the segment shown in FIG. It is a block diagram which shows the coupling | bond part with the voice coil for a drive of the segment of FIG. It is a block diagram which shows the drive part of the segment of FIG. It is a block diagram which shows the structure which fixes the drive part of FIG. It is a front view of the conventional spherical speaker. It is a block diagram which shows the shape of the diaphragm of FIG.1 and FIG.8. It is sectional drawing of another conventional spherical speaker.

Explanation of symbols

16 support column 16a air circulation hole 18 support base 18a air hole 100 diaphragm 101 segment (diaphragm segment)
101a Structure for joining voice coil 102 Edge part (elastic material)
DESCRIPTION OF SYMBOLS 110 Voice coil bobbin 111 Voice coil 112 Magnet side magnetic circuit support structure 113 Yoke 114 Magnet 115 Pole piece 116 Plate 117, 118 Segment support base (base)
119, 120 suspension 130 dodecahedron structure 131 frame 132 support base

Claims (3)

A substantially spherical diaphragm in which the surface of a substantially spherical body is divided into a plurality of polygonal segments and the boundaries of each segment are connected by an elastic material;
A plurality of voice coils respectively attached to an inner central portion of each of the plurality of segments;
A plurality of magnetic circuit structures including magnets arranged to face each of the plurality of voice coils;
A plurality of supports each supporting each of the plurality of magnetic circuit structures;
A plurality of suspensions respectively coupled to each of the plurality of supports so that each of the plurality of voice coils can vibrate in the coil axis direction;
Electroacoustic transducer equipped.   The electroacoustic transducer according to claim 1, wherein a plurality of the suspensions are provided for each voice coil. The substantially spherical diaphragm is a perpendicular line in which each triangle formed by a line segment drawn from the center of gravity of an n-gon (n: integer of 4 or more) and (n + 1) to each vertex is drawn from the center of gravity to each side. Is a combination of shapes folded into a V-shape, and is arranged at a position where the center of gravity of each polygon protrudes in the direction in which the radius increases, and the perpendicular foot drawn on each side is folded in the direction in which the radius decreases. And the legs of both perpendicular lines drawn on the common side of adjacent polygons are continuous,
The electroacoustic transducer according to claim 1 or 2, wherein the configuration is divided into a plurality of polygonal segments and boundaries of the segments are connected by the elastic material.

Images