JP2017139664A - Acoustic apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the volume of an acoustic apparatus.SOLUTION: In a conventional horn loudspeaker, a voice coil bobbin is provided on the outer periphery of a diaphragm 87 projecting from the edge 89 to the horn 84 side, and it was the inhibiting factor of compaction of the horn loudspeaker. In the horn loudspeaker 1, an electrical wire 88a is placed at the edge 89 supporting the diaphragm 87. Annular magnets 82c, 82b, 82a are parallel with the edge 89, and generate a magnetic field orthogonal to the current direction of the electrical wire 88a. The diaphragm 87 can be driven in the central axis ax direction, by feeding a current to the electrical wire 88a.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an acoustic device including an electroacoustic transducer represented by a speaker and an acoustoelectric transducer represented by a microphone.

  In an electroacoustic transducer represented by a speaker, a driving force is applied to a coil by passing a current through a coil placed in a magnetic field generated by a magnetic circuit, and a movable part such as a diaphragm is linked to the coil. There is a configuration one. Some acoustoelectric transducers represented by microphones use coils and magnetic circuits. However, in a microphone or the like, an electric signal is obtained from the coil by interlocking the coil with a movable part such as a diaphragm in a magnetic field generated by a magnetic circuit.

  FIG. 10 is a longitudinal cross-sectional view of a horn speaker 2 which is an example of an acoustic device using such a magnetic circuit and a coil, cut along a plane including the central axis ax. The part excluding the horn 84 from the horn speaker 2 shown in FIG. 10 is called a compression driver.

  As shown in FIG. 10, the throat portion 94 of the horn 84 is fixed to one end surface of the back plate 80. In the back plate 80, one bottom surface of the pole piece 85 is fixed to the end surface opposite to the horn 84. A sound guide hole 83 is provided in the center of the back plate 80 and the pole piece 85 so as to penetrate both of them and reach the throat portion 94 of the horn 84. The bottom surface of the pole piece 85 opposite to the back plate 80 is recessed in a mortar shape toward the sound guide hole 83, and a phase plug 86 is fitted into the mortar surface.

  The phase plug 86 has an axisymmetric shape with respect to the central axis ax of the horn speaker 2. The phase plug 86 is formed with a plurality of slits 91 that are axisymmetric with respect to the central axis ax. Here, the slit 91 is an elongated space that communicates the space behind the phase plug 86 and the space in front of the phase plug 86 (that is, the sound guide hole 83).

  A diaphragm 87, which is a movable part, is supported behind the phase plug 86 at a predetermined interval. The diaphragm 87 has a semi-spherical shape curved in a dome shape, and a cylindrical voice coil bobbin 88 is provided on the outer periphery of the diaphragm 87 on the horn 84 side.

  An end surface of the back plate 80 opposite to the horn 84 has an annular magnet 82 and a top plate 81 having the same diameter as the back plate 80, and the annular magnet 82 is sandwiched between the back plate 80 and the top plate 81 and supported. Has been. The annular magnet 82 has an N pole on one bottom surface (for example, the bottom surface on the back plate 80 side) and an S pole on the other bottom surface (for example, the bottom surface on the top plate 81 side).

  The inner peripheral surface of the top plate 81 is opposed to the outer peripheral surface of the pole piece 85 with a minute interval. And the part which consists of the back plate 80, the annular magnet 82, the top plate 81, the phase plug 86, and the pole piece 85 comprises the magnetic circuit which makes the magnetic force line which the annular magnet 82 generate | occur | produced. The diaphragm 87 is supported in a state in which the voice coil bobbin 88 is housed in a magnetic gap AG between the inner peripheral surface of the top plate 81 and the outer peripheral surface of the pole piece 85 of this magnetic circuit.

  The configuration for supporting the diaphragm 87 as the movable portion is as follows. First, a spacer ring 90 is fixed to the end surface of the top plate 81 opposite to the annular magnet 82. An edge 89 is interposed between the inner peripheral surface of the spacer ring 90 and the outer peripheral portion of the diaphragm 87. The edge 89 serves as a support portion that supports the diaphragm 87. Further, the horn speaker 2 includes a back cover 95 that covers the diaphragm 87 on the opposite side of the phase plug 86 with the diaphragm 87 interposed therebetween. An end surface of the back cover 95 is fixed to the spacer ring 90.

  In the horn speaker 2 having the above-described configuration, the magnetic flux generated by the annular magnet 82 passes through the magnetic gap AG between the top plate 81 and the pole piece 85. When a current is passed through the electric wire 88a in the voice coil bobbin 88, a driving force in a direction parallel to the central axis ax of the horn speaker 4 is given to the voice coil bobbin 88, and the diaphragm 87 fixed to the voice coil bobbin 88 vibrates. . When the diaphragm 87 vibrates, the vibration causes the air in the space OS between the diaphragm 87 and the phase plug 86 to be pushed out or pulled back to the sound guide hole 83 through the slits 91 of the phase plug 86. Then, the dense wave of the air that is pushed out or pulled back is emitted as a sound wave from the horn 84 via the sound guide hole 83. Patent Documents 1 to 3 disclose a horn speaker 2 as shown in FIG.

Registered Utility Model No. 3040179 JP-A-6-141390 JP 2011-244050 A

  By the way, in the conventional horn speaker 2, the voice coil bobbin 88 is provided in the outer peripheral part of the diaphragm 87 which protruded from the edge 89 to the horn 84 side, and this voice coil bobbin 88 makes the dimension of the center axis ax direction of the horn speaker 2 small. It was difficult to do.

  This problem also occurs in an acoustoelectric conversion device such as a microphone using a coil and a magnetic circuit.

  The present invention has been made in view of the above-described problems, and an object thereof is to reduce the volume of an acoustic device.

  In order to solve the above-described problems, the present invention provides a support part that supports a movable part, and a magnetic field that is disposed on the support part and is orthogonal to the movable direction of the movable part. And an electric wire for passing an electric current in a direction orthogonal to the acoustic device.

  In this invention, since the electric wire is arrange | positioned at the support part, it is not necessary to provide the area | region for arrange | positioning an electric wire in movable parts, such as a diaphragm. Therefore, according to the present invention, an acoustic device having a small volume can be realized.

  In a preferred aspect, the support portion is a substantially annular member having a periphery fixed to the acoustic device and a movable portion fixed to the center, and the acoustic device is placed on the support portion at a position facing the support portion. A magnetic field generator for generating parallel magnetic fields is provided.

  In the conventional horn speaker, it is necessary to provide a magnetic circuit so that the magnetic gap accommodates the voice coil bobbin provided on the outer peripheral portion of the horn side of the diaphragm, which is a factor in increasing the size of the horn speaker in the central axis direction. It was. On the other hand, according to this aspect, the magnetic field generation part which generates a magnetic field parallel to the support part is provided at a position facing the support part. Since this magnetic field generator does not need to generate a magnetic gap for accommodating the electric wire, it can be miniaturized. Therefore, it is possible to reduce the volume of the acoustic device.

  Moreover, this invention provides the compression driver characterized by the electric wire arrange | positioning at the edge.

  Since this compression driver has an electric wire disposed at the edge, the entire volume can be reduced.

It is the longitudinal cross-sectional view which cut | disconnected the horn speaker 1 which is one Embodiment of this invention by the plane containing the central axis ax. FIG. 4 is a rear view of the horn speaker 1 with the back cover 95 removed, as viewed from the back cover 95 toward the horn 84. FIG. 3 is a cross-sectional view of the horn speaker 1 shown in FIG. 2 cut along the line A-A ′ when a current flows from the terminal A to the terminal B. It is the rear view which looked at the same horn speaker 1 which removed the back cover 95 of the modification (1) from the direction which goes to the horn 84 from the back cover 95. FIG. 5 is a cross-sectional view of the horn speaker 1 shown in FIG. 4 taken along line B-B ′ when a current flows from the terminal A to the terminal B. It is the rear view which looked at the same horn speaker 1 which removed the back cover 95 of the modification (1) from the direction which goes to the horn 84 from the back cover 95. It is the rear view which looked at the same horn speaker 1 which removed the back cover 95 of the modification (2) from the direction which goes to the horn 84 from the back cover 95. It is sectional drawing which cut | disconnected the horn speaker 1 shown in FIG. 7 in the C-C 'line | wire, when an electric current flows into the terminal B from the terminal A. FIG. FIG. 6 is a cross-sectional view of the horn speaker 1 of Modification (3) cut along the line A-A ′ of FIG. 2 when a current flows from the terminal A to the terminal B. It is the longitudinal cross-sectional view which cut | disconnected the conventional horn speaker 2 by the plane containing the central axis ax.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view of a horn speaker 1 according to an embodiment of the present invention cut along a plane including a central axis ax. In the above-described conventional horn speaker 2 (see FIG. 10), the cylindrical voice coil bobbin 88 is provided on the outer periphery of the diaphragm 87 on the horn 84 side. On the other hand, in the horn speaker 1 according to the present embodiment, such a voice coil bobbin 88 is not provided. Instead, the back cover 95 side of the edge 89 that is a support portion that supports the diaphragm 87 that is a movable portion. An electric wire 88a is provided on the surface.

  Further, in the conventional horn speaker 2 (see FIG. 10) described above, a magnetic circuit including the back plate 80, the annular magnet 82, the top plate 81, the phase plug 86, and the pole piece 85 is provided. In this magnetic circuit, a magnetic field was generated in the magnetic gap AG between the top plate 81 and the pole piece 85, and the coil winding (electric wire 88a) of the voice coil bobbin 88 was passed.

  On the other hand, in the horn speaker 1 according to the present embodiment, the annular magnet 82 is replaced with the annular magnets 82a, 82b and 82c. These annular magnets 82 a, 82 b, and 82 c function as a magnetic field generator that generates a magnetic field that passes through the electric wire 88 a provided on the edge 89.

  As with the conventional ho-speaker 2, the edge 89 is a substantially annular member whose periphery is fixed to a horn speaker and whose center is fixed to a diaphragm 87 which is a movable portion. Here, the movable direction of the diaphragm 87 is a direction along the central axis ax. And the annular magnets 82a, 82b and 82c which are magnetic field generation parts are provided in the area which faces edge 89 which is a support part.

  In the present embodiment, the top plate 81 is replaced with a top plate 81a that is a non-magnetic material, and the pole piece 85 is replaced with a sound guide hole forming portion 85a that is a non-magnetic material. The reason why the top plate 81a and the sound guide hole forming portion 85a are non-magnetic is to prevent a short circuit of a magnetic field generated by the annular magnets 82a, 82b and 82c.

  In the present embodiment, the positions of the edge 89 and the top plate 81a are determined so that the distance between the edge 89 and the top plate 81a that is the inner wall surface of the horn speaker 1 is equal to the distance between the diaphragm 87 and the phase plug 86. Has been.

  In the present embodiment, the space between the edge 89 and the top plate 81a and the space between the diaphragm 87 and the phase plug 86 communicate to constitute one space, and this space has a uniform cross-sectional area of each part. It is a space. Except this, the horn speaker 1 and the horn speaker 2 are the same. Therefore, in FIG. 1, the same components as those shown in FIG. 10 are denoted by the same reference numerals, and the description thereof is omitted. Below, it demonstrates focusing on the annular magnets 82a, 82b and 82c, and the electric wire 88a.

  The annular magnet 82a is provided on the outer peripheral side of the horn speaker 1, the annular magnet 82b is provided with a gap between the inner peripheral side of the annular magnet 82a and the outer peripheral side of the annular magnet 82c, and the annular magnet 82c is provided on the inner peripheral side. It is provided in contact with the sound guide hole forming portion 85a. The annular magnet 82a has an S pole on the outer peripheral side surface of the horn speaker 1 and an N pole on the annular magnet 82b side surface. The annular magnet 82b has an N pole on the side surface on the annular magnet 82a side and an S pole on the side surface on the annular magnet 82c side. The annular magnet 82c has an S pole on the side surface on the annular magnet 82b side and an N pole on the side surface on the sound guide hole forming portion 85a side. The annular magnets 82 a, 82 b, and 82 c that are magnetic field generation units generate a magnetic field parallel to the edge 89.

  FIG. 2 is a rear view of the horn speaker 1 with the back cover 95 removed as viewed from the back cover 95 toward the horn 84. However, the spacer ring 90 is not shown in FIG. FIG. 2 shows a circular orbit D1 passing through the center between the outer periphery and inner periphery of the annular magnet 82c at the edge 89, a circular orbit D2 passing through the center between the outer periphery and inner periphery of the annular magnet 82b, and the annular magnet. A circular orbit D3 passing through the center between the outer periphery and the inner periphery of 82a is shown. The annular magnets 82 c, 82 b, and 82 a that are magnetic field generators respectively generate radial magnetic fields in three concentric annular regions (not shown) on the surface of the edge 89. The circular orbits D1, D2, and D3 are located at substantially the center in the width direction (radial direction) of each of the three annular regions.

  In FIG. 2, a drive voltage for driving the diaphragm 87 is applied to the terminals A and B. The electric wire 88a is one continuous electric wire wired in a single stroke along the circular tracks D1 to D3 from the terminal A to the terminal B. In the present embodiment, as shown in FIG. 2, the surface region of the annular edge 89 is divided into four regions AR1 to AR4 having a 90 ° divergence angle, and the electric wire 88a is in each region AR1 to AR4. In FIG. 2, the circular orbit D1 is sequentially traced from the circular orbit D3, or the circular orbit D3 is sequentially followed by the circular orbit D1 to reach the terminal B from the terminal A.

  More specifically, the electric wire 88a extends from the terminal A along the boundary between the areas AR1 and AR4 to a point C1 on the circular orbit D1 in the area AR1, and from there, 90 ° clockwise along the circular orbit D1. The point C2 near the boundary with the area AR2 is reached. Next, the electric wire 88a extends from this point C2 to a point C3 on the circular orbit D2 in the area AR1, and is near the boundary with the area AR4 which is 90 ° counterclockwise from the point C3 along the circular orbit D2. The point C4 is reached. Next, the electric wire 88a extends from this point C4 to a point C5 on the circular orbit D3 in the area AR1, and the boundary between the area AR2 and the area AR3 spaced 180 ° clockwise from the point C5 along the circular orbit D3. A nearby point C6 is reached. Next, the electric wire 88a extends from this point C6 to a point C7 on the circular orbit D2 in the area AR2, and between the area AR1 and the area AR2 spaced 90 ° counterclockwise from the point C7 along the circular orbit D2. The point C8 near the boundary is reached. Next, the electric wire 88a extends from this point C8 to a point C9 on the circular orbit D1 in the area AR2, and the boundary between the area AR3 and the area AR4 spaced 180 ° clockwise from the point C9 along the circular orbit D1. A nearby point C10 is reached. Hereinafter, the same applies, and the electric wire 88 reaches the terminal B via points C10 to C13 in the area AR3 and points C14 to C18 in the area AR4.

  3 is a cross-sectional view of the horn speaker 1 shown in FIG. 2 taken along the line A-A ′. The dotted arrows in FIG. 3 indicate the direction of the magnetic field generated by the annular magnets 82a, 82b and 82c. The section of the wire 88a between the points C1 and C2 that cuts the innermost annular region (the section of the leftmost wire 88a in FIG. 3), and the wire between the points C5 and C6 that cuts the outermost annular region. In the section 88a (the section of the rightmost wire 88a in FIG. 3), a magnetic field acts in the direction from the central axis ax toward the outer periphery of the edge 89 (the direction from left to right in FIG. 3). On the other hand, in the section of the electric wire 88a between the points C3 and C4 (the section of the central electric wire 88a in FIG. 3) vertically running through the center annular region, the direction from the outer peripheral side of the edge 89 toward the central axis ax (FIG. 3). Then, the magnetic field works in the direction from right to left. Thus, when the magnetic field generated in one annular region is a magnetic field in the direction from the center of the annular region to the periphery, the magnetic field generated in the adjacent annular region becomes a magnetic field in the direction from the periphery of the annular region to the center. . As described above, in this embodiment, the magnetic field generated in each annular region by the annular magnets 82a, 82b, and 82c is a radial direction and a magnetic field in the opposite direction between adjacent annular regions.

  FIG. 3 shows the direction of current in each section of the wire 88a when current flows from the terminal A to the terminal B. That is, in this case, the section of the wire 88a between the point C1 and the point C2 that vertically cuts in the innermost annular region, and the section of the wire 88a between the point C5 and the point C6 that cuts vertically in the outermost annular region. 2, the current flows in the clockwise direction in FIG. 2 (in the direction from the back to the front in FIG. 3), and in the section of the wire 88 a between the point C 3 and the point C 4 that cuts through the center annular region, the current flows. It flows in the counterclockwise direction of FIG. 2 (the direction from the front to the back in FIG. 3). Thus, in this embodiment, the direction of the electric current of the electric wire which cuts each between adjacent cyclic | annular area | regions is a reverse direction. Here, in the section of the wire 88a between the points C1 and C2, the section of the wire 88a between the points C5 and C6, and the section of the wire 88a between the points C3 and C4, the current direction and the magnetic field direction are The force acts in the direction from the horn 84 to the back cover 95 (upward in FIG. 3) in any section. For this reason, a force also acts on the edge 89 in the direction from the horn 84 to the back cover 95.

  On the other hand, when the current flows from the terminal B to the terminal A, the current flows counterclockwise in FIG. 2 in the section of the wire 88a between the points C1 and C2 and the section of the wire 88a between the points C5 and C6. In the section of the wire 88a between the points C3 and C4, current flows in the clockwise direction in FIG. Here, in the section of the electric wire 88a between the point C1 and the point C2, the section of the electric wire 88a between the point C5 and the point C6, and the section of the electric wire 88a between the point C3 and the point C4, the current direction and the magnetic field direction are different. The force acts in the direction from the back cover 95 to the horn 84 in any section. For this reason, a force also acts on the edge 89 in the direction from the back cover 95 to the horn 84.

  The areas AR2 to AR4 are the same as the area AR1 with the AA ′ line in FIG. 2, and when a current flows from the terminal A to the terminal B, a force acts on the edge 89 from the horn 84 to the back cover 95. When a current flows from the terminal B to the terminal A, a force acts on the edge 89 in the direction from the back cover 95 to the horn 84.

  Thus, when a current is passed through the electric wire 88a, a driving force in a direction parallel to the central axis ax is applied to the edge 89. And the diaphragm 87 which the edge 89 supports can be vibrated by changing the electric current sent through the electric wire 88a, and a sound wave can be generated.

  According to the horn speaker 1, since the voice coil bobbin 88 does not exist, it is not necessary to provide a magnetic gap AG between the back plate 80 and the edge 89. For this reason, space CS does not arise and the volume of the horn speaker 1 whole can be made small compared with the volume of the conventional horn speaker 2 whole.

  Furthermore, according to the present embodiment, an improvement in acoustic characteristics can be expected. In the conventional horn speaker 2, when the diaphragm 87 is vibrated at a certain frequency, the space between the voice coil bobbin 88 and the pole piece 85 and the space OS and the space between the voice coil bobbin 88 and the top plate 81 are combined. The space is regarded as a neck, and the space surrounded by the voice coil bobbin 88, the pole piece 85, the back plate 80 and the annular magnet 82, and the space surrounded by the spacer ring 90, the top plate 81, the voice coil bobbin 88 and the edge 89 are defined. Helmholtz resonance phenomenon considered as a cavity occurs. The Helmholtz resonance phenomenon occurs when there is a difference in the cross-sectional areas of the two spaces in the horn speaker 2 without being limited to these spaces. For this reason, at the frequency causing the Helmholtz resonance phenomenon, the vibration of the diaphragm 87 is adversely affected, a peak or dip occurs in the reproduction frequency characteristic of the horn speaker 2, and the sound quality of the emitted sound is deteriorated.

However, according to the horn speaker 1 in the present embodiment, the space between the edge 89 and the top plate 81a, and the space between the diaphragm 87 and the phase plug 86 communicate with each other to form one space. Since the cross-sectional area of each part is a uniform space, the occurrence of the Helmholtz resonance phenomenon that adversely affects the vibration of the diaphragm 87 can be suppressed. For this reason, the peak and dip of the frequency characteristic of the horn speaker 1 resulting from a Helmholtz resonance phenomenon can be suppressed.
<Other embodiments>

  Although one embodiment of the present invention has been described above, other embodiments are conceivable for the present invention. For example:

(1) In the said embodiment, although the electric wire 88a was arrange | positioned at the edge 89 as shown in FIG.2 and FIG.3, the aspect of arrangement | positioning of the electric wire 88a is not restricted to this. For example, as shown in FIGS. 4 and 5, the electric wire 88 a may be disposed on the edge 89. 4 is a rear view of the horn speaker 1 with the back cover 95 removed, as viewed from the back cover 95 toward the horn 84. FIG. 5 shows the horn speaker 1 shown in FIG. It is sectional drawing cut | disconnected. However, the spacer ring 90 is not shown in FIG.

  In the configuration of FIGS. 2 and 3, three circular tracks D1 to D3 are provided as tracks of the electric wire 88a. On the other hand, in the configuration of FIGS. 4 and 5, circular tracks D1 to D9 are provided in order from the inside as the track of the electric wire 88a, and the electric wire 88a between the terminals A and B is along the circular tracks D1 to D9. The circumference of the central axis ax is made 3 times.

  More specifically, the electric wire 88a connected to the terminal A has a circular path D1 → D4 → D7 in the area AR1, a circular path D7 → D4 → D1 in the area AR2, and an area AR3 in the first turn. The circular path D1 → D4 → D7 and the circular path D7 → D4 → D1 in the area AR4 are followed. Next, in the second turn, the electric wire 88a has a circular path D2 → D5 → D8 in the area AR1, a circular path D8 → D5 → D2 in the area AR2, and a circular path D2 → D5 → D8 in the area AR3. The path follows a circular path D8 → D5 → D2 in the area AR4. Next, in the third turn, the electric wire 88a has a circular path D3 → D6 → D9 in the area AR1, a circular path D9 → D6 → D3 in the area AR2, and a circular path D3 → D6 → D9 in the area AR3. The route follows the circular orbit D9 → D6 → D3 in the area AR4 and reaches the terminal B.

  As shown in FIG. 5, the magnetic field generated by the annular magnet 82c is orthogonal to the electric wires 88a on the circular tracks D1, D2, and D3, and the annular magnet 82b is generated on the electric wires 88a on the circular tracks D4, D5, and D6. The magnetic fields are orthogonal, and the magnetic field generated by the annular magnet 82a is orthogonal to the electric wires 88a on the circular tracks D7, D8, D9.

  As described above, in the configuration of FIGS. 4 and 5, the three electric wires 88a are orthogonal to the magnetic field generated by one annular magnet. Therefore, when the same current is supplied to the electric wire 88a, the force acting on the edge 89 shown in FIGS. 4 and 5 is three times the force acting on the edge 89 shown in FIGS.

  Further, the arrangement of the electric wires 88a with respect to the edge 89 may be arranged as shown in FIG. 2 and 3, the electric wire 88a is one continuous electric wire wired in a single stroke, but in FIG. 6, the electric wire 88a is composed of a plurality of electric wires. In FIG. 6, electric wires 88 a are arranged along the circular tracks D <b> 1 to D <b> 3 with respect to the edge 89, and each electric wire 88 a is connected in parallel to the electric wires 88 a extending from the terminals A and B. In FIG. 6, the direction of the current flowing in the section of the innermost peripheral wire 88 a of the edge 89 coincides with the direction of the current flowing in the section of the outermost peripheral wire 88 a of the edge 89 and is the second from the innermost periphery of the edge 89. The direction of the current flowing in the section of the electric wire 88a is opposite.

(2) The wire 88a wound in a coil shape may be disposed on the edge 89. FIG. 7 is a rear view of the horn speaker 1 with the back cover 95 removed in this case, as viewed from the back cover 95 toward the horn 84. As shown in FIG. 7, when the electric wire 88a is wound in a coil shape and disposed on the edge 89, the directions of the currents flowing in all the sections of the electric wire 88a coincide. FIG. 8 is a cross-sectional view of the horn speaker 1 shown in FIG. 7 cut along the line C-C ′. However, as shown in FIG. 8, in this case, the horn speaker 1 has one annular magnet 82. The annular magnet 82 functions as a magnetic field generator that generates a radial magnetic field parallel to the edge 89 in one annular region surrounding the diaphragm 87 that is a movable portion at the edge 89 that is a support portion. FIG. 8 shows the current direction of the electric wire 88a when a current flows from the terminal A to the terminal B. As shown in FIG. 7 and FIG. 8, in the annular region where the annular magnet 82 generates a magnetic field, an electric wire 88 a that vertically cuts the annular region a plurality of times is arranged, and the current in each electric wire that intersects the cross section of the annular region The direction is the same direction. Here, the cross section is a plane crossing the annular region in the direction of the magnetic field generated by the annular magnet 82, specifically, the cross section indicated by the C-C 'line in FIG. Therefore, when an electric current is passed through the electric wire 88a, a driving force in a direction parallel to the central axis ax is given to the edge 89, and by changing the electric current passed through the electric wire 88a, the diaphragm 87 supported by the edge 89 is vibrated. Can be generated.

  Further, three electric wires that are provided between a pair of terminals and form concentric circles with respect to the edge 89 may be arranged. In this aspect, a driving voltage for driving the diaphragm 87 is applied between three pairs of terminals to which three concentric electric wires are respectively connected.

(3) In the above embodiment, the annular magnets 82a, 82b and 82c have the south pole or the north pole on each of the outer peripheral side and the inner peripheral side of the horn speaker 1, but the back cover 95 side and the horn 84 side. There may be an S pole or an N pole on each of the side surfaces.

  FIG. 9 is a cross-sectional view of the horn speaker 1 in this case, taken along the line A-A ′ of FIG. 2. FIG. 9 shows the direction of current in each section of the wire 88a when current flows from the terminal A to the terminal B. In this case, the horn speaker 1 has annular magnets 82d to 82g. As shown in FIG. 9, the annular magnets 82d and 82f have an N pole on the side surface on the back cover 95 side and an S pole on the side surface on the horn 84 side. Further, the annular magnets 82e and 82g have an S pole on the side surface on the back cover 95 side and an N pole on the side surface on the horn 84 side. A non-magnetic material 96 is sandwiched between the annular magnets 82d to 82g in order to prevent a short circuit of a magnetic field generated by the annular magnets 82d to 82g.

  In the section of the innermost wire 88a of the edge 89 (the section of the leftmost wire 88a in FIG. 9), the magnetic field extends in the direction from the central axis ax toward the outer periphery of the edge 89 (the direction from left to right in FIG. 9). Work. Further, the section of the second electric wire 88a from the innermost periphery of the edge 89 (section of the central electric wire 88a in FIG. 9) and the section of the outermost electric wire 88a (section of the rightmost electric wire 88a in FIG. 9) A magnetic field acts in a direction from the outer peripheral side of the edge 89 toward the central axis ax (a direction from right to left in FIG. 9). When the current flows from the terminal A to the terminal B, a force acts in the direction from the horn 84 to the back cover 95 (upward in FIG. 9). For this reason, a force also acts on the edge 89 in the direction from the horn 84 to the back cover 95. On the other hand, when a current flows from the terminal B to the terminal A, a force acts in the direction from the back cover 95 to the horn 84 (downward in FIG. 9), and a force acts on the edge 89 in the direction from the back cover 95 to the horn 84.

  Thus, when a current is passed through the electric wire 88a, a driving force in a direction parallel to the central axis ax is applied to the edge 89. And the diaphragm 87 which the edge 89 supports can be vibrated by changing the electric current sent through the electric wire 88a, and a sound wave can be generated.

(4) In the above embodiment, a nonmagnetic material may be provided at each boundary of the annular magnets 82a to 82c.

(5) In the above embodiment, the top plate 81a is inserted between the spacer ring 90 and the annular magnet 82a. However, the top plate 81a may not exist. When the top plate 81a is not present, the volume of the entire horn speaker can be further reduced. However, in order to suppress the occurrence of Helmholtz resonance, the distance between the edge 89 and the annular magnets 82a to 82c needs to be equal to the distance between the diaphragm 87 and the phase plug 86.

(6) In the above embodiment, the electric wire 88 a is provided on the back cover 95 side of the edge 89, but may be provided on the horn 84 side of the edge 89. If the electric wire 88a is arranged so as to be orthogonal to the direction of the magnetic field of the annular magnets 82a to 82c, and the diaphragm 87 can be vibrated by changing the electric current flowing through the electric wire 88a, the position where the electric current 88a is provided to the edge 89 Can be anywhere.

(7) In the above embodiment, the diaphragm 87 has a dome shape, but the shape of the diaphragm 87 is not limited to a dome shape. For example, when the present invention is applied to a flat speaker, the diaphragm 87 is a flat surface.

(8) The horn speaker has a front type in which the sound radiation surface of the diaphragm 87 is curved in a convex shape with respect to the sound output direction, and the sound radiation surface of the diaphragm 87 is curved in a concave shape with respect to the sound output direction. There is a rear type. Although the horn speaker 1 of the said embodiment was a rear type, you may apply this invention to a front type horn speaker.

(9) Application for production, use, transfer, lending, export, import, transfer or lending of a compression driver alone (hereinafter referred to as “production etc.”) except for the horn 84 from the horn speaker 1 of the above embodiment. You may do. Further, the phase plug 86 alone of the above embodiment may be produced.

(10) Although the present invention is applied to a horn speaker in the above embodiment, the present invention may be applied to an acoustic device other than a horn speaker. For example, the present invention may be applied to a microphone. By applying the present invention to a microphone, the volume of the entire microphone can be reduced.

1, 2 ... Horn speaker, 80 ... Back plate, 81, 81a ... Top plate, 82, 82a-82g ... Ring magnet, 83 ... Sound introduction hole, 84 ... Horn, 85 ... Pole piece, 85a …… Sound guide hole forming portion, 86 …… Phase plug, 87 …… Diaphragm, 88 …… Voice coil bobbin, 88a …… Wire, 89 …… Edge, 90 …… Spacer ring, 91 …… Slit, 94 …… Throat part, 95... Back cover, 96 .. nonmagnetic material, ax... Central axis, OS .. space, AG .. magnetic gap, A, B .. terminal, C1 to C18. ……circular orbit.

Claims (6)

A support part for supporting the movable part;
An acoustic device comprising: an electric wire that is disposed on the support portion and flows an electric current in a direction perpendicular to both the movable direction and the direction of the magnetic field in a magnetic field orthogonal to the movable direction of the movable portion. . The support part is a substantially annular member whose periphery is fixed to the acoustic device and the movable part is fixed at the center,
The acoustic device according to claim 1, further comprising a magnetic field generation unit that generates the magnetic field parallel to the support unit at a position facing the support unit.   The acoustic device according to claim 2, wherein one magnetic field line in the magnetic field intersects with the plurality of electric wires. The magnetic field generator generates radial magnetic fields in a plurality of concentric annular areas surrounding the movable part in the support part, respectively, and reverse magnetic fields between adjacent annular areas,
4. The plurality of annular regions, wherein electric wires are arranged along a circular orbit traversing each of the plurality of annular regions, and the current direction of each electric wire is opposite between adjacent annular regions. Sound equipment. The magnetic field generation unit generates a magnetic field in one annular region surrounding the movable unit in the support unit,
The sound according to claim 3, wherein an electric wire that cuts the annular region a plurality of times is arranged in the annular region, and a current direction in each electric wire that intersects a cross section of the annular region is the same direction. machine. A compression driver characterized in that electric wires are arranged at the edges.

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