JP2009201005A - Motor-driven type speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven type speaker that suppresses a peak dip of playback sound pressure frequency characteristics, improves efficiency, also sufficiently increases a playback sound pressure level and improves playback audio quality, the motor-driven type speaker comprising a voice coil including an elongated coil and an elongated bobbin having a long-diameter direction and a short-diameter direction, an elongated diaphragm where the bobbin is fixed in the center, and an edge. <P>SOLUTION: A supporting movable part of the edge includes a long-side roll portion corresponding to a long side of a track shape of an inner circumferential part and a short-side roll portion corresponding to a circular arc of the inner circumferential part. The cross-sectional shapes and dimensions of the short-side roll portion are approximately equal to the cross-sectional shapes and dimensions of the long-side roll portion in a connected portion with the long-side roll portion and in the short-diameter direction. At the same time, a roll width is gradually changed so as to become maximum in the vicinity corresponding to a connecting corner portion of a long side and a short side in an outer circumferential part of the edge. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an elongate electrodynamic speaker having a shorter minor axis direction than a major axis direction, excellent in sound reproduction capability, and suitable for being attached to a device such as a display.

  In an audio device such as a display to which a speaker for reproducing sound is attached, it is desired to reduce the space required for attaching the speaker. In particular, slender (rectangular, oval (including elliptical, track-shaped)) electrodynamic speakers have a diaphragm area limited in the minor axis direction, and are affected by the division vibration that is typical of slender speaker diaphragms. It is difficult to obtain a large and flat reproduction sound pressure frequency characteristic, and if a magnetic circuit for a speaker with a high magnetic gap magnetic flux density is used, the magnetic circuit is wider than the speaker diaphragm and cannot be reduced in size. There are disadvantages in audio playback capability for various reasons. Therefore, conventionally, various speaker diaphragms, edges, speaker magnetic circuits, and electrodynamic speakers using the same have been proposed to solve these problems.

  In the case of a conventional elongated speaker, in the case where a diaphragm having a major axis direction and a minor axis direction such as an oval (track shape or elliptical shape) is provided, the inner peripheral portion of the edge that supports the diaphragm is It is often formed in an oval shape (track shape or oval shape) along the shape of the outer peripheral end of the diaphragm. On the other hand, for example, coupled to the outer periphery of an elliptical or non-circular diaphragm, the width on the minor axis side is narrower than the width on the major axis direction side of the diaphragm, and at any position over the entire circumference. There is an edge for a speaker having the same length when deployed (Patent Document 1).

  Further, for example, it has a substantially elliptical diaphragm and an elongated outer shape larger than the diaphragm, and the diaphragm is arranged at the approximate center to support the diaphragm and around the diaphragm. Each of the frames has a substantially frame shape having an edge formed by a roll portion protruding in a vibration direction having a substantially arc-shaped cross section, a pair of long frames, and a pair of short frames. The edge of the edge is fixed, and the vibration plate is supported by the frame so as to be free to vibrate through the edge, and the roll portions oppose each other along the longitudinal direction of the edge. In the electroacoustic transducer formed in a track shape including a pair of longitudinal portions and a pair of arc-shaped portions connecting the pair of longitudinal portions at both ends thereof, the roll portion includes the longitudinal portion and the arc-shaped portion. The cross-sectional shape in the vicinity of the connecting part where the part is connected Kicking width and the projecting height, there is are speakers have progressively larger so formed portion toward from the connecting portion near the top of the arc-shaped portion (Patent Document 2).

  On the other hand, conventionally, in the case of a so-called square speaker in which the coupling portion with the roll edge has a diaphragm having a substantially rectangular edge, the curvature of the roll inside of the arc portion of the roll edge coupled to the corner of the diaphragm. There is a rectangular speaker having the same or larger than the outer curvature (Patent Document 3). The roll width of the edge part joined to the corner part of the diaphragm is larger than that of the straight part, and the inner circumferential curvature is large, so that the increase in compliance due to circumferential expansion and contraction is suppressed. And the overall compliance of the edge can be reduced, whereby the lowest resonance frequency can be reduced, and the low-frequency reproduction capability can be expanded.

Japanese Patent Laid-Open No. 7-46690 (FIGS. 1 and 2) JP 2004-297315 A (FIGS. 6 to 8) Japanese Utility Model Publication No. 3-14878 (FIGS. 1a to 2b)

  However, none of the prior art speakers are sufficient. The speaker described in Patent Document 2 is a special speaker having a track-like shape in which the outer diameter of the bobbin of the voice coil and the outer diameter of the diaphragm are substantially the same, and the bobbin of the voice coil is at the center of the diaphragm. It is not necessarily suitable for a long and narrow speaker. In addition, when the circular voice coil and the bobbin are connected to the center of the diaphragm, the edge described in Patent Document 1 or 3 is effective, but the diaphragm is an elongated speaker having a track shape or an elliptical shape. Since the diameter of the circular voice coil to be used for this is limited to be small so as not to protrude from the elongated diaphragm, the length of the voice coil located in the magnetic gap of the magnetic circuit is shortened. There is a problem that the sound pressure level is low and the input resistance is poor.

  The present invention has been made in order to solve the above-described problems of the prior art, and an object of the present invention is to provide an elongated coil having a major axis direction and a minor axis direction and a voice coil including an elongated bobbin, For an electrodynamic speaker with an elongated diaphragm and an edge with a bobbin fixed to its center, the peak dip of the sound pressure frequency characteristic can be suppressed, the efficiency is high, and the sound pressure level is sufficiently high An object of the present invention is to provide an electrodynamic speaker excellent in reproduction sound quality.

  An electrodynamic speaker according to the present invention includes an elongated coil having a major axis direction and a minor axis direction and a voice coil including an elongated bobbin, an elongated diaphragm in which the bobbin is fixed to the center thereof, An electrodynamic type comprising: an inner peripheral part joined to the outer peripheral end part; an outer peripheral part joined to the fixed part of the frame; and a slender edge including a support movable part connecting the inner peripheral part and the outer peripheral part. A track in which the outer peripheral end of the diaphragm and the inner peripheral portion of the edge are formed of a set of long sides along the major axis direction and a set of arcs connecting the set of long sides. The outer peripheral part of the edge and the fixed part of the frame are formed of a pair of long sides along the major axis direction and a pair of short sides along the minor axis direction connecting the pair of long sides. The long side corresponding to the long side of the track shape of the inner periphery And a short-side roll portion corresponding to the arc of the inner peripheral portion, and the cross-sectional shape and dimensions of the short-side roll portion are connected to the long-side roll portion and the long-side roll in the short-diameter direction. It gradually changes so that the roll width becomes the maximum in the vicinity of the cross-sectional shape and size of the portion, and in the vicinity corresponding to the long side and the short side of the outer peripheral portion of the edge.

  Preferably, in the electrodynamic speaker according to the present invention, a first roll portion in which the cross-sectional shape of the long side roll portion of the support movable portion of the edge is continuously formed on the planar inner peripheral portion, and the first roll portion And a second roll part formed continuously.

  Preferably, in the electrodynamic speaker of the present invention, the cross-sectional shape of the short side roll part of the support movable part of the edge is the first roll part defined by the radius r1, and 0.25 times to 1.0 times the radius r1. A second roll portion defined by a radius r2 set in a double range, and the first roll portion is defined in the vicinity corresponding to the long side of the outer peripheral portion of the edge and the connecting corner portion with the short side. The radius R1 is set in a range of 2.0 to 4.0 times the radius r1, and the radius R2 defining the second roll portion is in a range of 2.0 to 4.0 times the radius r2. Is set.

  Preferably, in the electrodynamic speaker of the present invention, the elongated edge includes a front edge having a long side roll portion having a substantially convex cross section, and a rear edge obtained by inverting the front edge back and forth. In addition, the inner peripheral portion of the front edge is connected to the front side of the outer peripheral end portion of the diaphragm, and the inner peripheral portion of the rear edge is connected to the rear side of the outer peripheral end portion of the diaphragm.

  Preferably, the electrodynamic speaker of the present invention further includes an elongated frame having a fixed portion, and a magnetic circuit connected to the frame and having an elongated magnetic gap, and the elongated shape of the voice coil. A coil is placed in the magnetic gap.

  The operation of the present invention will be described below.

  An electrodynamic speaker according to the present invention includes an elongated coil having a major axis direction and a minor axis direction and a voice coil including an elongated bobbin, an elongated diaphragm in which the bobbin is fixed to the center thereof, An electrodynamic type comprising: an inner peripheral part joined to the outer peripheral end part; an outer peripheral part joined to the fixed part of the frame; and a slender edge including a support movable part connecting the inner peripheral part and the outer peripheral part. It is a speaker. Preferably, an elongated frame including a fixing portion and a magnetic circuit connected to the frame and having an elongated magnetic gap are further provided, and the elongated coil of the voice coil is disposed in the magnetic gap. Therefore, even when the space for mounting the audio equipment is narrow, an elongated electrodynamic speaker that is excellent in reproduction sound quality that can be mounted is realized.

  In the electrodynamic speaker of the present invention, the outer peripheral end portion of the diaphragm and the inner peripheral portion of the edge include a set of long sides along the major axis direction and a set of arcs connecting the set of long sides. The outer periphery of the edge and the fixed portion of the frame are a set of long sides along the major axis direction and a pair of short sides along the minor axis direction connecting the pair of long sides. And a substantially rectangular shape. Therefore, the support movable part of the edge has a long side roll part corresponding to the long side of the track shape of the inner peripheral part, and a short side roll part corresponding to the arc of the inner peripheral part. The cross-sectional shape and dimensions of the part are approximately equal to the cross-sectional shape and dimensions of the long-side roll part in the short-diameter direction and the connecting part with the long-side roll part, and the connection angle with the long and short sides of the outer peripheral part of the edge It gradually changes so that the roll width becomes the largest in the vicinity corresponding to the part. That is, the cross-sectional shape and dimensions of the short-side roll part are larger than the short-diameter direction of the long-side roll part and the short-side roll part at the connecting corner portion of the edge.

  Specifically, the cross-sectional shape of the long side roll part of the support movable part of the edge includes a first roll part formed continuously without a bending point in the planar inner peripheral part, and a first roll part. And a second roll portion formed continuously without having a bending point. That is, the first roll part is a concave roll part, and the radius r1 that defines the first roll part is set to a range of 0.25 to 1.0 times the radius r2 that defines the second roll part that is the convex roll part. Is done. Further, in the vicinity corresponding to the long side of the outer peripheral portion of the edge and the connecting corner portion with the short side, the radius R1 defining the first roll portion is 2 of the radius r1 defining the first roll portion of the long side roll portion. The radius R2 that is set in the range of 0.0 times to 4.0 times and that defines the second roll portion is 2.0 times to 4.0 times the radius r2 that defines the second roll portion of the long side roll portion. Set to double range.

  Therefore, in the electrodynamic speaker of the present invention, the shape of the elongated edge is set as described above, so that even if the elongated diaphragm that fixes the voice coil bobbin is fixed to the center of the diaphragm is compared. Therefore, a flat reproduction sound pressure frequency characteristic can be obtained. That is, since the cross-sectional shape and dimensions of the short side roll portion of the edge are gradually changed, an elongated voice coil is used so as to secure the length of the voice coil located in the magnetic gap of the magnetic circuit. Even an electrodynamic speaker can suppress the divided vibration of the diaphragm, increase the efficiency and the reproduction sound pressure level, and improve the reproduction sound quality and input resistance.

  Preferably, the electrodynamic loudspeaker includes a front edge having a long side roll portion having a substantially convex cross-sectional shape, and a rear edge obtained by inverting the front edge back and forth. The inner peripheral portion of the edge may be connected to the front side of the outer peripheral end portion of the diaphragm, and the inner peripheral portion of the rear edge may be connected to the rear side of the outer peripheral end portion of the diaphragm. In addition, that the cross-sectional shape is substantially convex means that the overall shape in the cross-section protrudes to one side with reference to the planar inner peripheral portion or outer peripheral portion as in the edge of the present invention. By providing the front edge and the rear edge, the front-rear symmetry of the amplitude displacement of the diaphragm is improved, and even-order distortion represented by the second-order distortion, and the reproduced sound quality with less malfunction such as rolling It is possible to provide an electrodynamic speaker that excels in performance.

  An electrodynamic speaker according to the present invention includes an elongated coil having a major axis direction and a minor axis direction, a voice coil including an elongated bobbin, and an elongated diaphragm and an edge to which the bobbin is fixed at the center. To provide an electrodynamic speaker that can suppress the peak dip of playback sound pressure frequency characteristics, is highly efficient, has a sufficiently high playback sound pressure level, and has excellent playback sound quality even for electrodynamic speakers. Can do.

  In the electrodynamic speaker of the present invention, the object of the present invention is achieved by connecting the outer peripheral end of the diaphragm and the inner peripheral portion of the edge to a pair of long sides along the major axis direction and a pair of long sides. A track shape formed from a pair of arcs, and the outer peripheral part of the edge and the fixed part of the frame are in the minor axis direction connecting the pair of long sides along the major axis direction and the pair of long sides. A substantially rectangular shape formed from a pair of short sides along which the support movable portion has a long side roll portion corresponding to the track-shaped long side of the inner peripheral portion and a short portion corresponding to the arc of the inner peripheral portion. The cross-sectional shape and dimensions of the short-side roll part are substantially equal to the cross-sectional shape and dimensions of the long-side roll part in the short diameter direction, and The roll width becomes the largest in the vicinity corresponding to the long side of the outer peripheral part and the connecting corner part with the short side. By you gradually change to cormorants, it was realized.

  Hereinafter, although the electrodynamic speaker by preferable embodiment of this invention is demonstrated, this invention is not limited to these embodiment.

  FIG. 1 is a diagram illustrating an electrodynamic speaker 1 according to a preferred embodiment of the present invention. FIG. 1A is a perspective view of the electrodynamic speaker 1 as viewed from the front side obliquely upward, and FIG. 1B is a perspective view of the magnetic circuit 10 constituting the electrodynamic speaker 1 from the front side obliquely upward. FIG. The electrodynamic speaker 1 of this embodiment is an elongated electrodynamic speaker having a track-shaped speaker diaphragm 2 having a major axis length of about 15.0 cm and a minor axis direction length of about 2.5 cm. As will be described later, a part of the structure of the electrodynamic speaker 1, the internal structure, and the like are omitted. The direction in which the straight line connecting the points A-A ′ extends is the major axis direction, and the direction in which the straight line connecting the points B-B ′ extends is the minor axis direction.

  The speaker diaphragm 2 whose outer shape and inner shape are track-shaped is a flat diaphragm formed by press-molding foamed PP, and the outer peripheral end of the edge 3 is supported by an edge 3. It is fixed to. Further, a voice coil 4 (not shown) composed of a bobbin and a coil is connected to the inner peripheral end of the speaker diaphragm 2, and a dome-shaped dust cap 5 whose outer shape is a track shape is bonded to the upper end thereof. ing. Here, the track shape is a shape formed by a set of long sides along the major axis direction and a set of arcs connecting the set of long sides, and the outer peripheral end of the speaker diaphragm 2. The inner peripheral end of the edge 3 has a set of long sides and a set of arcs connecting the set of long sides. Note that the speaker diaphragm 2 may be a flat diaphragm that press-molds PSP, PP, paper, aluminum alloy, or the like, or may be formed by punching a planar material that is formed into a thin plate shape. .

  The frame 6 has an elongated shape corresponding to the track-shaped speaker diaphragm 2, and the magnetic circuit 10 fixed to the frame 6 also has an elongated shape having a narrow width less than the length in the minor axis direction. Specifically, the fixed portion of the frame 6 is formed of a set of long sides along the major axis direction and a set of short sides along the minor axis direction connecting the pair of long sides. The outer shape has a major axis length of about 17.0 cm and a minor axis length of about 3.0. Parts forming the vibration system such as the voice coil 4 are exposed from a window (not shown) on the back side of the frame 6. Therefore, the electrodynamic speaker 1 is a speaker suitable for a device having a small width for mounting the speaker, such as a side portion of a display unit included in a device such as a display.

  The magnetic circuit 10 includes an elongated top plate 11 fixed to the frame 6, and a center pole 12 that is inserted into a track-shaped hole formed in the center of the top plate 11, which has a track-shaped long cylindrical shape. And an elongated under plate 14 in which the center pole 12 is disposed in the center, and a magnet 15 sandwiched between the top plate 11 and the under plate 14. The top plate 11 and the center pole 12 form a track-shaped magnetic air gap 13 having an equal width. That is, the magnetic circuit 10 is an outer magnet type magnetic circuit having a track-shaped magnetic gap 13, and the major axis direction and minor axis direction of the magnetic circuit 10 are the same as the major axis direction and minor axis direction of the track-shaped speaker diaphragm 2. I'm doing it.

  The voice coil 4 (not shown) is formed from a bobbin formed in a long cylindrical shape having a track-shaped cross section, and a coil that is wound around one end thereof and supplied with an audio current. The bobbin is connected to the inner peripheral end of the speaker diaphragm 2 by an adhesive at the outer side surface close to the other end side where the coil is not wound. The voice coil 4 is supported by the edge 3 through the speaker diaphragm 2 so as to be able to vibrate, and the track-shaped coil is disposed in the track-shaped magnetic gap 13 of the magnetic circuit 10. The major axis length of the coil is about 22.0 mm, the minor axis length is about 6.0 mm, and the radius of the track-shaped arc is about 3.0 mm. Therefore, the speaker vibration system including the speaker diaphragm 2, the edge 3, the voice coil 4, and the dust cap 5 is supported so as to be able to vibrate with respect to the frame 6. In the electrodynamic speaker 1, when an audio current is supplied to the coil of the voice coil 4, a driving force is applied to the voice coil 4 disposed in the magnetic gap 13, and the voice coil 4 vibrates in the front-rear direction and is connected. The speaker diaphragm 2 also vibrates in the front-rear direction. In the electrodynamic loudspeaker 1, front and rear refers to the side where the voice coil 4 and the magnetic circuit 10 are attached when the speaker diaphragm 2 vibrates, and the speaker diaphragm 2 and the dust cap 5. The side where is exposed is the front side.

  2 and 3 are diagrams for explaining the edge 3 according to a preferred embodiment of the present invention. FIG. 2 is a plan view of the edge 3, and FIG. 3 is a partial sectional view of the edge 3 in FIG. is there. The edge 3 is, for example, substantially annular by injecting foam rubber into the mold, hot press molding and foaming to obtain a predetermined shape, cutting the inner peripheral side and the outer peripheral side with a cutting die This is an edge for a speaker formed in the shape of an elongated roll edge. The edge 3 has a thickness of about 0.2 mm, a major axis length of about 150 mm, and a minor axis direction length of about 25.0 mm. The inner diameter of the edge 3 is about 135.8 mm in the major axis direction, about 11.2 mm in the minor axis direction, and the radius of the track-shaped arc is about 5.6 mm. The edge 3 is formed by, for example, impregnating rubber into a woven fabric in which a plurality of warps and wefts of cotton and polyester fibers are substantially perpendicular to each other to form a base material, and heat-molding with a mold to cut the inner periphery and outer periphery. It may be an elongated roll edge.

  As shown in the partial cross-sectional view in the minor axis direction of FIG. 3, the edge 3 includes a track-shaped planar inner peripheral portion 31 that is bonded to the outer peripheral end portion of the speaker diaphragm 2 and a plane that is bonded to the frame 6. A track-shaped outer peripheral portion 32, and a support movable portion 33 configured by a roll shape in which a radial cross section connecting the inner peripheral portion 31 and the outer peripheral portion 32 is continuous. The support movable portion 33 includes a concave roll portion 33a continuously formed without a bending point on the planar inner peripheral portion 31, and a convex portion formed continuously without a bending point on the concave roll portion 33a. And a roll portion 33b. Specifically, for example, in the B-O cross section in the minor axis direction, the width Lw of the support movable portion 33 is about 2.5 mm, and the radius r1 defining the concave roll portion 33a is about 1.67 mm, convex. The radius r2 defining the cylindrical roll portion 33b is about 0.75 mm. The radius r2 that defines the convex roll portion 33b is preferably set in the range of 0.25 to 1.0 times the radius r1 that defines the concave roll portion 33a. r2 is about 0.44 times the radius r1. Moreover, the maximum height of the support movable part 33 of the edge 3 is substantially constant over the entire circumference, and is about 1.5 mm.

  As shown in the plan view of FIG. 2, the support movable portion 33 of the edge 3 includes a long side roll portion 34 x corresponding to the track-shaped long side 34 of the inner peripheral portion 31, and an arc 35 of the inner peripheral portion 31. Short side roll part 35x corresponding to. Further, the outer peripheral portion 33 of the edge 3 includes a set of long sides 36 along the long diameter direction and a set of short sides 37 along the short diameter direction connecting the set of long sides 36. Yes. In FIG. 2, the length L1a in the major axis direction is the length of the long side 34 of the inner peripheral portion 31, and the length L2a in the major axis direction is the length of the long side 36 of the outer peripheral portion 33. Further, the length L1b in the minor axis direction is the diameter of the arc 35 of the inner peripheral portion 31, and similarly, the length L2b in the minor axis direction is the length of the short side 37 of the outer peripheral portion 33.

  In the long side roll part 34 x constituting the support movable part 33 of the edge 3, the roll shape shown in the cross-sectional view of FIG. 3 continues over the track-shaped long side 34 of the inner peripheral part 31. That is, the edge 3 has a constant roll width Lw and a cross-sectional shape at a portion corresponding to the length L1a of the long side 34 of the inner peripheral portion 31, and the short side roll portion 35x corresponding to the arc 35 of the inner peripheral portion 31. The cross-sectional shape of the arc 35 in the normal direction changes as the angle defining the arc 35 changes. This is because the inner peripheral portion 31 of the edge 3 has a track shape corresponding to the track shape of the speaker diaphragm 2, whereas the outer peripheral portion 32 of the edge 3 corresponds to the substantially rectangular shape of the fixed portion of the frame 6. It is because it is a substantially rectangular shape. That is, the edge 3 gradually changes so that the roll width Lw ′ becomes the largest in the vicinity of the outer peripheral portion 32 corresponding to the long side 36 and the connecting corner portion 38 with the short side 37. In the case of the present embodiment, the outer end of the connecting portion 38 formed by the long side 36 and the short side 37 of the outer peripheral portion 33 is edged by a small arc as shown in the plan view of FIG. Yes.

  FIG. 4 is a diagram for explaining a change in the cross-sectional shape of the connecting portion 38 of the edge 3. That is, in the short-side roll part 35x formed following the long-side roll part 34x of the edge 3, the state in which the cross-sectional shape and the roll width Lw ′ change is illustrated by a cross-sectional view shown at 15 ° intervals. is there. The cross-sectional shape of the short side roll part 35x includes a concave roll part 33a and a convex roll part 33b in the long side roll part 34x. First, at 0 ° shown in FIG. 4A, the cross-sectional shape and dimensions of the short-side roll portion 35x are substantially equal to the cross-sectional shape and roll width Lw of the long-side roll portion 34x. At 15 ° shown in FIG. 4 (b) and 30 ° shown in FIG. 4 (c), the cross-sectional shape and dimensions of the short-side roll part 35x change, and the roll width Lw ′ is compared with the roll width Lw at 0 °. growing. 45 ° shown in FIG. 4D corresponds to the connecting corner portion 38 where the long side 36 and the short side 37 are connected, and the short side roll portion 35x has the largest roll width Lw ′. Furthermore, at 60 ° shown in FIG. 4 (e) and 75 ° shown in FIG. 4 (f), the cross-sectional shape and dimensions of the short-side roll portion 35x change, and the roll width Lw ′ becomes smaller. And the cross-sectional shape and dimension of the short side roll part 35x become substantially equal again to the cross-sectional shape and roll width Lw of the long side roll part 34x in the short diameter direction which is 90 degrees shown in FIG.4 (g). ing.

  Specifically, in the case of the present embodiment, the roll width Lw ′ is the largest at the connecting corner portion 38 in the case of 45 ° shown in FIG. 4D, and the roll width Lw ′ is about It becomes 4.27 mm. Moreover, the cross-sectional shape of the short side roll part 35x becomes the shape which the concave roll part 33a and the convex roll part 33b spread. When the radius defining the concave roll portion 33a at the connecting corner portion 38 is R1, and the radius defining the convex roll portion 33b is R2, the radius R1 is about 5.41 mm and the radius R2 is about 2.73 mm. . Each of the radii R1 is about 3.24 times the radius r1 that defines the concave roll portion 33a in the long side roll portion 34x, and the radius R2 defines the convex roll portion 33b in the long side roll portion 34x. It is about 3.64 times the radius r2. Thus, it is preferable that the radii R1 and R2 at the connecting corner portion 38 are set in the range of 2.0 times to 4.0 times the radii r1 and r2.

  FIG. 5 is a graph showing on-axis 1 m sound pressure frequency characteristics of the electrodynamic speaker 1 having the speaker vibration system including the edge 3 of the present embodiment. The electrodynamic speaker 1 of the present embodiment includes the edge 3, the track-type speaker diaphragm 2, and the track-type voice coil 4. Therefore, the track-type voice coil, the elongated speaker diaphragm, Therefore, it is possible to suppress the divided vibration at 300 Hz or more, which is likely to be generated by the combination, and to realize a smooth frequency characteristic. In addition, since the electrodynamic speaker 1 of the present embodiment uses the edge 3 that realizes the above frequency characteristics, the track-type voice coil 4 and the magnetic circuit 10 having the track-shaped magnetic gap 13 are provided. Used to achieve a high reproduction sound pressure level of about 80 dB / m / W. That is, as can be seen in comparison with a comparative example described later, the speaker is an electrodynamic speaker that is highly efficient and excellent in reproduction sound quality while being an elongated speaker.

  FIG. 6 is a graph showing on-axis 1 m sound pressure frequency characteristics of another electrodynamic speaker (not shown) including another edge (not shown) of the comparative example. 6A is a graph showing the on-axis 1 m sound pressure frequency characteristic of the electrodynamic speaker 101 of Comparative Example 1, and FIG. 6B is the on-axis 1 m of the electrodynamic speaker 102 of Comparative Example 2. It is a graph showing a sound pressure frequency characteristic. Since the electrodynamic speaker 1 of the present embodiment and the electrodynamic speaker of the comparative example 1 or the comparative example 2 have the same configuration of the speaker diaphragm 2, the frame 6, and the like other than the parts for comparative study, Description of these will be omitted.

  The difference between the electrodynamic speaker 101 of Comparative Example 1 is the shape of the edge 103 (not shown) and the shape of the voice coil 104 and the magnetic circuit 110 (not shown). That is, the edge 103 of Comparative Example 1 is a conventional edge shape in which the cross-sectional shape of the support movable portion and the roll width do not change over the entire circumference of the track shape, and the roll width is constant at about 2.5 mm. The voice coil 104 of Comparative Example 1 is a circular voice coil having a circular bobbin and a diameter of about 6.0 mm, and the magnetic circuit 110 corresponding thereto also has a circular magnetic gap 113 with a small radius. . As a result, as shown in FIG. 6A, in the frequency band of 300 Hz to 10 kHz, an axial 1 m sound pressure frequency characteristic in which a peak dip appears repeatedly appears. Further, in addition to the magnetic circuit 110 becoming smaller than the magnetic circuit 10 of the present embodiment, the coil length of the circular voice coil 104 disposed in the magnetic gap 113 of the magnetic circuit 110 is the same as that of the present embodiment. Since the electrodynamic speaker 101 of Comparative Example 1 has a low reproduction sound pressure level of about 72 dB / m / W, the electrodynamic speaker is inferior in reproduction sound quality because it is shorter than the track-shaped voice coil 4. It is a type speaker.

  On the other hand, the only difference between the electrodynamic speaker 102 of Comparative Example 2 is the shape of the edge 103 (not shown). That is, the edge 103 of the comparative example 2 is the same as the case of the above comparative example 1, and is a conventional edge shape in which the cross-sectional shape and the roll width of the support movable part do not change over the entire circumference of the track shape. The roll width is constant at about 2.5 mm. In Comparative Example 2, the voice coil 104 and the magnetic circuit 10 have the same track shape as in the present example, and the reproduction sound pressure level is about 78 dB / m / W. There is no reduction in sound pressure level and efficiency. However, in the case of the comparative example 2, as shown in FIG. 6B, the peak dip appears repeatedly in the frequency band of 300 Hz to 10 kHz, and the disturbance becomes larger than that of the comparative example 1. . Further, the sound pressure frequency characteristic on the shaft is such that the level further decreases as it goes up, and this tendency tends to be seen in a speaker including an elongated speaker diaphragm 2 including a track-shaped voice coil 4. And the electrodynamic speaker 102 of the comparative example 2 is also an electrodynamic speaker inferior in reproduction | regeneration audio | voice quality.

  Therefore, the electrodynamic speaker 1 of this embodiment fixes the bobbin of the track-shaped voice coil 4 to the center of the track-shaped speaker diaphragm 2 by making the shape of the elongated edge 3 as described above. Even if it is a thing, a comparatively flat reproduction | regeneration sound pressure frequency characteristic can be acquired. That is, since the cross-sectional shape and roll width Lw ′ of the short-side roll portion 35x of the edge 3 are gradually changed from the shape and dimensions of the long-side roll portion 34x, The divided vibration of the speaker diaphragm 2 can be suppressed even when the coil length of the voice coil 4 positioned is ensured by adopting a track shape. In addition, increasing the efficiency and playback sound pressure level, which tend to decrease with slender electrodynamic speakers, results in the need to input excessive audio signal power and increase the rated input. It is possible to realize an electrodynamic speaker that is superior in voice and has improved input resistance and quality.

  FIG. 7 is a diagram for explaining an electrodynamic speaker 1a (not shown) according to another preferred embodiment of the present invention, and an enlarged view of an edge portion of the electrodynamic speaker 1a in the minor axis direction (B-O cross section). It is sectional drawing. That is, the electrodynamic speaker 1a of the present embodiment is an embodiment in which the configuration of the elongated edge 3 joined to the outer peripheral end portion of the speaker diaphragm 2 is different from the electrodynamic speaker 1 of the previous embodiment. Yes, specifically, the front edge 3 having the long-side roll portion 34x having a substantially convex cross section described in the previous embodiment, and the rear edge 3Z having a shape obtained by inverting the front edge 3 back and forth, , Including.

  As in the previous embodiment, the front edge 3 has a track-shaped flat inner peripheral portion 31 that joins the outer peripheral end of the speaker diaphragm 2, and a track-shaped outer peripheral portion 32 that has a flat surface that joins the frame 6. And a support movable portion 33 configured in a roll shape in which a radial cross section connecting the inner peripheral portion 31 and the outer peripheral portion 32 is continuous. Accordingly, the support movable portion 33 has a shape including the concave roll portion 33a and the convex roll portion 33b, and the convex roll portion 33b forms a substantially convex roll edge that largely protrudes to the front side. ing. Further, the inner peripheral portion 31 of the front edge 3 is connected to the front side of the outer peripheral end portion of the speaker diaphragm 2, and the outer peripheral portion 32 of the front edge 3 is connected to the front side of the fixed portion of the frame 6.

  On the other hand, the rear edge 3Z may have a shape obtained by inverting the front edge 3 back and forth, and the edge 3 formed through the same manufacturing process may be used in a reverse manner. Therefore, the support movable portion 33 of the rear edge 3Z includes a concave roll portion 33a and a convex roll portion 33b. Contrary to the front edge 3, the convex roll portion 33b has a large rear side. A roll edge protruding to the side is formed. The inner peripheral portion 31 of the rear edge 3Z is connected to the rear side of the outer peripheral end portion of the speaker diaphragm 2, and the outer peripheral portion 32 of the rear edge 3Z is connected to the rear side of the fixed portion of the frame 6. is doing.

  Therefore, the electrodynamic speaker 1a of the present embodiment includes the front edge 3 and the rear edge 3Z obtained by inverting the front edge 3 back and forth. Therefore, when the speaker diaphragm 2 undergoes amplitude displacement, The front-rear asymmetry associated with the shape is offset, and as a result, the front-rear symmetry is improved. Since the front-rear symmetry affects even-order distortion represented by second-order distortion, it is possible to realize an electrodynamic speaker 1a with less distortion and excellent reproduction sound quality. In addition, it is possible to provide an electrodynamic speaker that is less prone to malfunction such as rolling of the speaker vibration system, has high input resistance, and excellent reproduction sound quality.

  Moreover, the edge 3 which comprises the electrodynamic speaker of this invention is not limited to the case where it shape | molds from the foamed rubber of the said Example, A material, such as foaming urethane, may be sufficient. The elastic material forming the speaker edge may be molded by, for example, injecting rubber or elastomer into an injection mold. Alternatively, an elastomer sheet may be press-molded.

  The electrodynamic speaker of the present invention is not limited to a track-shaped speaker diaphragm and a speaker using a track-shaped voice coil, and is driven by an elongated diaphragm that emits sound waves, and the elongated diaphragm. The present invention can also be applied to other electric-mechanical-acoustic transducers having other vibration systems in which a driving member that transmits force has a combination of elongated shapes.

It is a figure explaining the electrodynamic speaker 1 by preferable embodiment of this invention. Example 1 It is a figure explaining the edge 3 by preferable embodiment of this invention. Example 1 It is a figure explaining the edge 3 by preferable embodiment of this invention. Example 1 It is a figure explaining the change of the cross-sectional shape of the connection part 38 of the edge 3 by preferable embodiment of this invention. Example 1 It is a graph showing the 1-m sound pressure frequency characteristic on the axis | shaft of the electrodynamic speaker 1 by preferable embodiment of this invention. Example 1 It is a graph showing the 1m sound pressure frequency characteristic on an axis of electrodynamic type speakers 101 and 102 of a comparative example. (Comparative Example 1 and Comparative Example 2) It is an expanded sectional view about the edge part of the minor axis direction of the electrodynamic speaker 1a by other preferable embodiment of this invention. (Example 2)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrodynamic type speaker 2 Speaker diaphragm 3 Edge 5 Dust cap 6 Frame 10 Magnetic circuit 11 Top plate 12 Center pole 13 Magnetic gap 14 Underplate 15 Magnet 31 Inner peripheral part 32 Outer peripheral part 33 Support movable part 34 Length of inner peripheral part Side 35 Short side 36 of the inner peripheral part 36 Long side 37 of the outer peripheral part Short side 38 of the outer peripheral part Connection angle part

Claims (5)

An elongated coil having a major axis direction and a minor axis direction and a voice coil including an elongated bobbin, an elongated diaphragm in which the bobbin is fixed to the center thereof, and an inner end joined to an outer peripheral end of the diaphragm An electrodynamic speaker comprising a peripheral portion, an outer peripheral portion joined to a fixed portion of the frame, and an elongated edge including a support movable portion connecting the inner peripheral portion and the outer peripheral portion,
The outer peripheral end portion of the diaphragm and the inner peripheral portion of the edge are formed of a set of long sides along the major axis direction and a set of arcs connecting the set of long sides. The outer periphery of the edge and the fixed portion of the frame are a pair of long sides along the major axis direction and a pair along the minor axis direction connecting the pair of long sides. A pair of short sides, and a substantially rectangular shape formed from the long side roll portion corresponding to the long side of the track shape of the inner peripheral portion and the arc of the inner peripheral portion. A corresponding short-side roll portion, and the cross-sectional shape and dimensions of the short-side roll portion are the connecting portion with the long-side roll portion, the cross-sectional shape of the long-side roll portion in the short-diameter direction, and the The roll width is the same as that of the outer periphery of the edge and the corner corresponding to the connecting corner with the short side. Gradually change to be listening,
Electrodynamic type speaker. A cross-sectional shape of the long side roll part of the support movable part of the edge is formed continuously with the first roll part formed continuously with the planar inner peripheral part, and with the first roll part. A second roll part,
The electrodynamic speaker according to claim 1. The cross-sectional shape of the short side roll part of the support movable part of the edge is set in a range of 0.25 times to 1.0 times the first roll part defined by the radius r1 and the radius r1. A second roll part defined by a radius r2, and a radius defining the first roll part in the vicinity of the edge corresponding to the long side of the outer peripheral part and the connecting corner part with the short side R1 is set in a range of 2.0 times to 4.0 times of the radius r1, and a radius R2 defining the second roll portion is 2.0 times to 4.0 times of the radius r2. Set to a range,
The electrodynamic speaker according to claim 2. The elongated edge includes a front edge having the long-side roll portion having a substantially convex cross-sectional shape, and a rear edge obtained by inverting the front edge back and forth, and the inner peripheral portion of the front edge is , Connected to the front side of the outer peripheral end portion of the diaphragm, the inner peripheral portion of the rear edge is connected to the rear side of the outer peripheral end portion of the diaphragm,
The electrodynamic speaker according to any one of claims 1 to 3.   The elongated frame including the fixing portion, and a magnetic circuit coupled to the frame and having an elongated magnetic gap, the elongated coil of the voice coil being disposed in the magnetic gap. The electrodynamic speaker according to any one of claims 1 to 4.