JP2012249029A - Electrodynamic speaker - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrodynamic speaker using a flat coil having a winding axis direction orthogonal to a vibration direction of a speaker diaphragm, which is an elongated electrodynamic speaker having a shorter minor axis direction than a major axis direction. In addition, an electrodynamic speaker having excellent sound reproduction capability and suitable for being attached to a device such as a display is provided.
An electrodynamic speaker includes a voice coil including a first coil, a second coil, and a third coil that are bonded together, a speaker diaphragm coupled to the voice coil, and a linear magnet in which the voice coil is disposed. The magnetic circuit having the air gap is accommodated in the inner peripheral space defined by the inner peripheral end of the voice coil formed by bonding the first coil, the second coil, and the third coil, and the outer peripheral end is the inner A damper having a reinforcing plate portion that engages with the peripheral end portion, and a movable portion that extends from the reinforcing plate portion so as to vibrate and is connected to a frame or a magnetic circuit.
[Selection] Figure 3

Description

  The present invention relates to an elongated voice coil and an electrodynamic loudspeaker whose short diameter direction is shorter than the long diameter direction. In particular, the present invention relates to a voice coil that is excellent in sound reproduction capability and suitable for being attached to a device such as a display, and an electrodynamic speaker using the same.

  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, an electrodynamic loudspeaker intended to be slender may be limited in slenderness depending on the configuration of the magnetic circuit. In addition, slender (rectangular, oval (including elliptical, track-shaped)) electrodynamic speakers employ a speaker magnetic circuit with a high magnetic flux density in the magnetic gap, where the diaphragm area is limited in the minor axis direction. When trying to do so, there is a disadvantage in the sound reproduction capability for various reasons such as the magnetic circuit is wider than the speaker diaphragm and cannot be downsized. Therefore, in order to solve these problems, various magnetic circuits for speakers and electrodynamic speakers using the same have been proposed.

  Conventionally, in order to reduce the thickness of an electrodynamic speaker, there is a speaker provided with a plate-like driving force transmission member on which a voice coil is formed. For example, a frame, a magnetic circuit fixed to the frame, a diaphragm fixed to the frame so as to vibrate in a predetermined direction, a driving force transmission member coupled to the diaphragm, and the driving force A damper that supports the transmission member, wherein the magnetic circuit is disposed between a first plane and a second plane, and the first plane is a plane parallel to the diaphragm. The second plane is defined as a plane that is parallel to the diaphragm and that is in contact with at least a part of the magnetic circuit. The driving force transmission member has a region where a voice coil is formed, and the driving force transmission member is generated by the action of a current flowing through the voice coil and a magnetic flux provided by the magnetic circuit. The driving force in a predetermined direction is transmitted to the diaphragm, and one end of the damper is coupled to the driving force transmission member at a position between the first plane and the second plane. And the other end of the damper is coupled to the frame at a position between the first plane and the second plane. (Patent Document 1).

  In addition, as a speaker including a plate-like driving force transmission member on which a voice coil is formed, for example, a plane vibration plate is attached to the back surface of the plane vibration plate along the vibration direction so that the plane is flat. There is a flat drive speaker comprising a drive plate on which a coil is formed and a magnet that applies a magnetic field to the coil of the drive plate, and the drive plate is a printed wiring board on which a coil is printed. (Patent Document 2).

  In addition, even if a plate-like driving force transmission member is not provided, a voice coil formed of a flat coil having two linear sides facing each other at the center of a rectangular or oval diaphragm A square dynamic formed by joining one linear side surface to a diaphragm so as to be substantially perpendicular to the plate, and arranging a magnetic circuit so that the magnetic flux interlinking with the voice coil is perpendicular to the coil plane. There is a speaker (Patent Document 3). Alternatively, a diaphragm that is supported so as to vibrate in a predetermined direction, a pair of magnets arranged opposite to each other in a direction orthogonal to the vibration direction of the diaphragm, and a direction parallel to each other of the pair of magnets A voice coil wound around the direction of the winding axis, and the voice coil is joined to the diaphragm at a portion where current flows in one direction perpendicular to the winding axis direction and the vibration direction. There is a speaker device in which a portion flowing in the other direction is arranged to face the pair of magnets (Patent Document 4).

Japanese Patent No. 3891481 (FIGS. 1 to 11) Japanese Utility Model Publication No. 58-48194 (FIGS. 1 to 3) Japanese Utility Model Publication No. 59-189398 (FIGS. 1 to 3) JP 2007-129665 A (FIGS. 1 to 9)

  However, it includes an elongated electrodynamic speaker having a shorter minor axis direction than the major axis direction, and includes a flat coil disposed so that the direction of the coil winding axis is orthogonal to the vibration direction of the speaker diaphragm. In this case, for example, when a plate-like driving force transmission member as in Patent Document 1 is provided, the weight of the speaker vibration system is increased, the magnetic flux density in the linear magnetic gap is reduced, and the sound is reduced. Problems such as a reduction in the reproduction efficiency of the speaker for reproducing the image may occur. On the other hand, for example, when the plate-like driving force transmission member as in Patent Document 4 is not provided, the driving force acting on the portion of the flat coil disposed in the magnetic gap of the magnetic circuit is affected by the rigidity of the flat coil. Due to the shortage, it is not sufficiently transmitted to the speaker diaphragm joined to the flat coil, the high frequency limit frequency is lowered and a sufficient sound reproduction band cannot be secured, and as a result, an electrodynamic speaker inferior in sound reproduction ability There is a problem of becoming. In addition, in an elongated electrodynamic speaker including a flat coil, there is a problem that it is difficult to hold the voice coil at the center with respect to the magnetic circuit.

  The present invention has been made to solve the above-described problems of the prior art, and an object of the present invention is to provide an electrokinetic motor using a flat coil having a winding direction perpendicular to the vibration direction of the speaker diaphragm. The present invention is to provide an electrodynamic speaker that is a slender electrodynamic speaker that has a shorter minor axis direction than a major axis direction, has excellent sound reproduction capability, and is suitable for mounting on a device such as a display. .

  The electrodynamic loudspeaker of the present invention includes a first coil, a second coil, and a third coil, which are flat-plate air-core coils in which a rectangular wire is wound in multiple layers without being displaced with respect to the winding axis. The coil end faces are bonded to each other so that they coincide with each other, and the bonded first coil, second coil, and third coil are connected in series or in parallel so that the audio signal current flows in the same direction. Configured voice coil, speaker diaphragm connected to the voice coil, magnetic circuit having a linear magnetic gap in which the voice coil is disposed, a frame connected to the magnetic circuit, and an outer peripheral end fixed to the frame The voice coil formed by bonding the edge supporting the outer peripheral end of the speaker diaphragm and the first coil, the second coil, and the third coil A reinforcing plate part that is housed in an inner peripheral space defined by the inner peripheral end part and whose outer peripheral end part engages with the inner peripheral end part, and extends from the reinforcing plate part so as to vibrate and is attached to the frame or the magnetic circuit. A damper having a movable part to be coupled.

  In the electrodynamic speaker of the present invention, the damper is composed of a pair of damper members arranged in a direction along the winding axis of the voice coil, and each damper member is an inner peripheral end of the voice coil. A reinforcing plate part that is housed in an inner peripheral space defined by the part and whose outer peripheral end engages with the inner peripheral end part, and is movable so as to be able to vibrate from the reinforcing plate part and connect to a frame or a magnetic circuit The thickness of the reinforcing plate portion of the two damper members that are overlapped with each other is smaller than the voice coil thickness dimension defined by the thickness of the first coil, the second coil, and the third coil bonded together.

  In the electrodynamic speaker of the present invention, the inner diameter of each of the second coil and the third coil sandwiching the first coil is larger than the inner diameter of the inner periphery of the first coil. The inner peripheral end portion of the voice coil formed by bonding the first coil, the second coil, and the third coil includes an engaging step portion with which the reinforcing plate portion of the damper is engaged.

  Preferably, in the electrodynamic speaker of the present invention, the second coil and the third coil have one or more turns less than the number of turns at the inner peripheral end of the flat air core coil having the same number of turns as the first coil. The inner peripheral end portions of the second coil and the third coil are formed so as to have an inner diameter dimension larger than the inner diameter dimension of the inner peripheral end portion of the first coil.

  Preferably, in the electrodynamic speaker of the present invention, the reinforcing plate portion of the damper includes an engaging step portion that engages with an engaging step portion of the inner peripheral end portion of the voice coil at the outer peripheral end portion thereof.

  In the electrodynamic speaker according to the present invention, the first coil, the second coil, and the third coil have a track shape including a set of straight portions and a set of arc portions, or a rectangular shape including two sets of straight portions. The outer peripheral end portion of the reinforcing plate portion of the damper includes at least one set of linear portions that engage with the set of linear portions of the first coil, the second coil, and the third coil. .

  The operation of the present invention will be described below.

  In the electrodynamic speaker of the present invention, the voice coil has a flat plate shape in which a rectangular wire (including a square wire, a true square wire, and an edgewise wire) having a rectangular cross section is wound in multiple layers without being shifted with respect to the winding axis. This is a voice coil formed by bonding three coil end faces to each other so that their winding axes coincide with each other. The first coil, the second coil, and the third coil bonded together with an adhesive or varnish are connected in series or in parallel so that an audio signal current flows in the same direction. Therefore, the voice coil of the present invention is formed in a thin flat plate shape whose thickness is about three times the thickness of the flat wire. The first coil, the second coil, and the third coil that are wound in multiple layers without shifting the rectangular wire with respect to the winding axis have a problem that they are easily warped and deformed individually, but like the voice coil of the present invention, respectively. When the coil end faces are bonded together, deformation can be prevented and a flat plate shape can be maintained.

  A voice coil is formed into an elongated track shape or a rectangular shape as a whole, and when a part of the voice coil is arranged in a linear magnetic gap of a magnetic circuit, the minor axis direction is shorter than the major axis direction. Can be realized. The electrodynamic speaker of the present invention includes a speaker diaphragm connected to a voice coil, a frame connected to a magnetic circuit, an edge that supports an outer peripheral end of the speaker diaphragm by fixing its outer peripheral end to the frame, An inner peripheral portion is connected to the voice coil, and an outer peripheral portion is provided with a damper connected to the frame or the magnetic circuit. The first coil, the second coil, and the third coil are formed in one of a track shape including a set of linear portions and a set of arc portions, or a rectangular shape including two sets of linear portions, and a damper. It is only necessary that the outer peripheral end portion of the reinforcing plate portion includes at least one set of linear portions that engage with the set of linear portions of the first coil, the second coil, and the third coil.

  Here, the damper is accommodated in an inner circumferential space defined by the inner circumferential end of the voice coil formed by bonding the first coil, the second coil, and the third coil, and the outer circumferential end is the inner circumference. A reinforcing plate that engages with the end; and a movable portion that extends from the reinforcing plate so as to vibrate and is connected to a frame or a magnetic circuit. Preferably, the damper is constituted by a pair of damper members arranged in a direction along the winding axis of the voice coil, and each damper member is formed in an inner circumferential space defined by an inner circumferential end of the voice coil. A reinforcing plate that is housed and whose outer peripheral end engages with the inner peripheral end, and a movable part that extends from the reinforcing plate so as to vibrate and is connected to a frame or a magnetic circuit, The thicknesses of the reinforcing plate portions of the two damper members thus formed are smaller than the voice coil thickness dimension defined by the thickness obtained by bonding the first coil, the second coil, and the third coil.

  That is, in the electrodynamic speaker of the present invention, the first coil, the second coil, and the third coil, which are flat air-core coils, are formed in a track shape or a rectangular shape, and these are bonded to each other. Since the coil has an inner peripheral space defined by an inner peripheral end formed by bonding the first coil, the second coil, and the third coil, the damper is accommodated in the inner peripheral space, and the outer periphery thereof. A reinforcing plate portion whose end portion engages with the inner peripheral end portion is formed, and the voice coil is held in the center with respect to the magnetic gap of the magnetic circuit so as to be able to vibrate without coming into contact therewith. The thickness of the reinforcing plate portion of the damper is made smaller than the voice coil thickness dimension defined by the thickness of the first coil, the second coil, and the third coil bonded together, and does not protrude from the inner circumferential space. That is, since the reinforcing plate portion of the damper is made smaller than the thickness dimension of the voice coil to which the first coil, the second coil, and the third coil are bonded, the inner peripheral space defined by the inner peripheral end portion of the voice coil. It is accommodated without protruding from and reinforces the voice coil. In the voice coil, the first coil, the second coil, and the third coil are formed in either a track shape including a set of straight portions and a set of arc portions, or a rectangular shape including two sets of straight portions. And it is preferable that the outer peripheral edge part of a reinforcement board contains a set of linear part which engages with a set of linear part of a 1st coil and a 2nd coil at least.

  Therefore, in the electrodynamic speaker according to the present invention, the damper connected to the voice coil can be provided with a reinforcing plate, so that the rigidity can be increased, and the driving force acting on the portion of the voice coil that is disposed in the magnetic gap of the magnetic circuit. However, the driving force is sufficiently transmitted to the speaker diaphragm connected to the voice coil. As a result, this electrodynamic speaker can secure a wide audio reproduction band by increasing the high frequency limit frequency. In addition, the reinforcing plate part of the damper can be realized with the minimum volume accommodated in the inner circumferential space of the voice coil, so that the weight can be reduced, and the linear magnetic gap dimension suitable for the thickness dimension of the voice coil can be obtained. Therefore, it is not necessary to widen, and a high magnetic flux density can be maintained. Therefore, it is possible to increase the sound reproduction efficiency and to make an electrodynamic speaker with excellent sound reproduction ability.

  In the voice coil of the present invention, the track-shaped or rectangular inner peripheral end portion may include an engagement step portion with which the reinforcing plate is engaged. Specifically, each inner peripheral end of the second coil and the third coil sandwiching the first coil has an inner diameter that is larger than the inner diameter of the inner peripheral end of the first coil to be bonded. If it has, the engagement step part which a reinforcement board engages with the inner peripheral edge part is formed in both sides. When the second coil and the third coil are formed by reducing the number of windings at the inner peripheral end of the flat air core coil having the same number of turns as the first coil by one turn or more, these turns are used. The engagement step portion with which the reinforcing plate is engaged may be formed using the difference in the inner diameter due to the difference in number.

  Further, the reinforcing plate portion of the damper of the electrodynamic speaker of the present invention may include an engaging step portion that engages with an engaging step portion of the inner peripheral end portion of the voice coil at the outer peripheral end portion thereof. . Since the reinforcing plate portion of the damper having the engaging step portion at the outer peripheral end engages with the inner peripheral end portion of the first coil and the inner peripheral end portion of the second coil or the third coil, The mounting accuracy can be increased and the rigidity can be further increased. Therefore, the voice coil of the present invention can balance the improvement in the reproduction efficiency of the electrodynamic speaker using the same and the slenderness, and can realize the electrodynamic speaker excellent in reproduction sound quality.

  The electrodynamic speaker using a flat coil having a winding direction perpendicular to the vibration direction of the speaker diaphragm, and in particular, a track shape formed by multilayer winding without shifting a rectangular wire with respect to the winding direction. It is an elongate electrodynamic speaker having a coil with a short axis direction shorter than the major axis direction, excellent in sound reproduction capability, and suitable for mounting on a device such as a display. it can.

It is a figure explaining the electrodynamic speaker 1 by preferable embodiment of this invention. Example 1 It is a partially expanded sectional view explaining the structure of the electrodynamic speaker 1 by preferable embodiment of this invention. Example 1 It is a figure explaining the voice coil 4 and the damper 5 by preferable embodiment of this invention. Example 1 It is sectional drawing explaining the structure of the voice coil 4 and the damper 5 by preferable embodiment of this invention. Example 1

  Hereinafter, a voice coil and an electrodynamic speaker according to preferred embodiments of the present invention will be described, but the present invention is not limited to these embodiments.

1 and 2 are diagrams illustrating an electrodynamic speaker 1 according to a preferred embodiment of the present invention. 3 and 4 are views for explaining the voice coil 4 and the damper 5 according to a preferred embodiment of the present invention. Specifically, FIG. 1 is a perspective view of the electrodynamic speaker 1 viewed from the front side, and FIG. 2 is a partially enlarged view of the cross section of the electrodynamic speaker 1 in the minor axis direction. 3A is a cross-sectional perspective view of the voice coil 4 and the damper 5 in the minor axis direction, FIG. 3B is a cross-sectional view thereof, and FIG. 4 is a development view of the voice coil 4 and the damper 5. It is. 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 (long axis) connecting the points A-O-A ′ extends is the major axis direction,
The direction in which the straight line (minor axis) connecting the two extends is the minor axis direction.

  The electrodynamic speaker 1 of the present embodiment is an elongated electrodynamic speaker having a track-shaped speaker diaphragm 2 having a major axis direction length L1 of about 135.6 mm and a minor axis direction length L2 of about 10.0 mm. The speaker has a diaphragm area equivalent to a circular diaphragm having an aperture of about 35 mm even if it is an elongated shape. The outer peripheral end of the speaker diaphragm 2 is supported by an edge 3, and the outer peripheral end of the edge 3 is fixed to the frame 6. In addition, a coil 4 is connected to the central portion of the speaker diaphragm 2 from the back side, and the coil 4 is supported so as to be able to vibrate by a damper 5 whose outer peripheral side is fixed to a frame 6. The coil 4 of this embodiment is a track-type coil, and is a flat coil having a winding axis direction in a direction substantially orthogonal to the vibration direction in which the speaker diaphragm 2 vibrates. Further, the frame 6 has an elongated shape corresponding to the track-shaped speaker diaphragm 2, and the magnetic circuit 10 fixed so as to be accommodated in the frame 6 also has an elongated shape having a narrow width of the minor axis direction length L2 or less. Have. Therefore, the electrodynamic speaker 1 is a speaker suitable for a device with a small width for mounting the speaker, such as a side surface of a display unit included in a device such as a display. A terminal 7 (not shown) to which an audio signal current is supplied is attached to the back side of the frame 6 and a part of the magnetic circuit 10 is exposed.

  The speaker diaphragm 2 of the electrodynamic speaker 1 has an inner peripheral side of an edge 3 bonded to an outer peripheral end thereof, and one linear portion 4b of a track-shaped coil 4 to be described later is slit on the center rear surface. It is inserted into the connection part in the shape and bonded with an adhesive. The speaker diaphragm 2 is formed by forming a foamed thermoplastic resin in order to reduce the weight of the speaker diaphragm. In the case of the present embodiment, the speaker diaphragm 2 having irregularities is obtained by using a vacuum forming method in which a thermoplastic resin foam sheet (specifically, polystyrene paper) that has been extruded is combined with plug assist molding. It has gained. That is, in the elongated speaker diaphragm 2 in which the major axis direction length L1 and the minor axis direction length L2 are remarkably different, the influence of divided vibration in the major axis direction is likely to be noticeable, so the minor axis direction cross-sectional shape includes a substantially U-shape. Thus, the shape has rigidity in the major axis direction.

  In this embodiment, the edge 3 is formed by injecting flexible foam rubber into a mold and heating and foaming. The long side of the track shape that extends linearly in the major axis direction of the speaker diaphragm 2 and the short side of the track shape that has an arc shape in the minor axis direction have a thin corrugation (or so as to freely support the speaker diaphragm 2). A free edge is formed by a roll. Note that, in the short side of the track shape, the edge that is arcuate in the minor axis direction may be formed as a fixed edge that is thick and does not vibrate freely so as to fix and support the speaker diaphragm 2. . As a result, the elongated speaker diaphragm 2 is flexibly supported by the compliance of the free edge portion of the edge 3 in the minor axis direction, while the thermoplastic resin foam sheet that forms the speaker diaphragm 2 in the major axis direction. Flexibility enables bending vibration.

  The coil 4 corresponds to a magnetic circuit 10 to be described later, and is a flat coil having a winding direction in a direction substantially orthogonal to a vibration direction in which the speaker diaphragm 2 vibrates, and has a major axis length of about The coil has a track shape of 36.2 mm, a minor axis length of about 8.2 mm, and a thickness 4 t of about 0.75 mm. Specifically, the coil 4 has a thickness (41t, 42t, 43t = about 0.25 mm) in which a copper rectangular wire having a thickness of 0.12 mm × 0.20 mm is wound in multiple layers without being shifted with respect to the winding axis. ) Includes three air-core coils 41, 42 and 43 formed in a flat plate shape having a thickness substantially equal to the thickness of the flat wire and a winding layer thickness of about 2.3 mm. The coil 4 is formed by bonding the respective coil end faces with an adhesive (or varnish) so that the winding axes of the coils 41, 42, and 43 coincide, and the bonded coils 41, 42, and 43 are It is a voice coil configured to be connected in series so that an audio signal current flows in the same direction. Since the coils 41 and 42 and 43 are wound in multiple layers without shifting the flat wire with respect to the winding axis, each of them has a problem of being easily warped and deformed, but when the coil end faces are bonded together, Deformation can be prevented and a flat plate shape can be maintained.

  In the track-shaped coil 4 to which the coils 41, 42, and 43 are bonded, one linear portion 4a, the other linear portion 4b, one arc portion 4c, and the other arc portion 4d are formed, On the inner peripheral side of the track-shaped inner peripheral end 4e, an inner peripheral space 4f that is a track-shaped hole is formed. The central coil 41 is disposed so as to be sandwiched between the coils 42 and 43. In addition, the coils 41, 42, and 43 that constitute the coil 4 may be coils having substantially the same number of turns. Preferably, the coils 42 and 43 may be formed by reducing the number of turns at the inner peripheral end of a flat-plate air-core coil having the same number of turns as the coil 41 sandwiched in the center by one or more turns. . Since the inner peripheral end portions of the coils 42 and 43 are configured to have an inner diameter dimension larger than the inner diameter dimension of the inner peripheral end portion of the coil 41, a damper 5 described later is provided on the inner peripheral end portion 4 e of the coil 4. An engaging step portion to which the reinforcing plate portion 5a is engaged is formed.

  The damper 5 is composed of a pair of damper members 51 and 52 arranged in a direction along the winding axis of the voice coil 4. The damper members 51 and 52 are dampers that have a common configuration and are formed by impregnating a phenol resin with a woven fabric of flexible fibers as a base material. Note that the damper 5 may be a damper formed by injection molding of resin, or may be an integrated set of two damper members 51 and 52, or may be formed by pressing a resin plate. Or a member formed. The damper 5 is connected to the coil 4 or the frame 6 by an adhesive. The damper members 51 and 52 include a reinforcing plate portion 5a connected to the voice coil 4, a down-roll-shaped movable portion 5b extending from the reinforcing plate portion 5a so as to vibrate, and a frame 6 extending from the movable portion 5b. And a fixing portion 5c coupled to the. The reinforcing plate portions 5a of the damper members 51 and 52 are bonded so as to be in close contact with each other, and the inner peripheral space defined by the inner peripheral end 4e of the voice coil 4 formed by bonding the coils 41, 42 and 43 together. 4f and the outer peripheral end 5e engages with the inner peripheral end 4e.

  In the damper 5, the thickness 5at (= 0.75 mm or less) of the reinforcing plate portion 5a of the two damper members 51 and 52 that are overlaid is defined by the thickness of the coils 41, 42, and 43 that are bonded together. It becomes smaller than 4t (= 0.75 mm). In the coil 4, two parallel sides of the outer peripheral end 5 e of the reinforcing plate portion 5 a of the damper 5 accommodated in the inner peripheral space 4 f are two parallel sides of the track-shaped inner peripheral end 4 e of the coil 4. Engage with. The reinforcing plate portion 5a of the damper 5 has an outer peripheral end portion 5e engaged with a track-shaped inner peripheral end portion 4e of the coil 4 and is bonded with an adhesive. That is, the outer peripheral end portion 5 e of the reinforcing plate portion 5 a of the damper 5 is engaged with the inner peripheral surface of the innermost winding of the coils 42 and 43. The reinforcing plate portion 5a of the damper 5 of the present embodiment has a rectangular shape having a major axis length of about 28.0 mm and a minor axis direction length of about 3.8 mm. Since the thickness of the reinforcing plate portion 5a of the damper members 51 and 52 is made smaller than the thickness dimension 42t or 43t of each of the coils 42 and 43, the reinforcing plate portion 5a of the damper 5 is separated from the inner peripheral space 4f of the coil 4. Does not protrude. Since the reinforcing plate portion 5a of the damper 5 increases the rigidity of the coil 4, it suppresses deformation such that the flat coil 4 warps. The reinforcing plate portion 5a of the damper 5 may be made of a nonmagnetic metal such as copper, duralumin, or an aluminum alloy, or may be made of a synthetic resin such as ABS, PI, or PET.

  The frame 6 is a resin that is injection-molded into an elongated basket shape corresponding to the shape of the speaker diaphragm 2, a substantially rectangular fixing portion that fixes the edge 3, a fixing portion that fixes the magnetic circuit 10, A connecting portion for connecting these fixing portions, a window defined between the plurality of connecting portions, and a mounting hole for attaching a terminal (not shown) are provided. Therefore, the speaker vibration system including the speaker diaphragm 2, the edge 3, the coil 4, and the damper 5 is supported so as to be able to vibrate with respect to the frame 6 and the magnetic circuit 10. The frame 6 may be a metal frame formed by press-molding a steel plate.

  The magnetic circuit 10 includes yokes 11 and 12 and two rod-like magnets 13 having a rectangular cross section that are connected to the yokes 11 and 12 to form a linear magnetic gap 14. The magnet 13 of this embodiment is a rod-like rare earth magnet and is magnetized so that each plane connected to the yoke 11 or 12 has a different magnetic pole property. Therefore, a magnetic field having a high magnetic flux density is formed in the linear magnetic gap 14. Is generated. Each member constituting the magnetic circuit 10 is fixed with an adhesive. The magnetic circuit 10 is also fixed to the fixing portion of the frame 6 with an adhesive. The magnetic circuit 10 is an elongated magnetic circuit having an outer dimension with a major axis length of about 40.0 mm and a minor axis direction length of about 6.2 mm, and is almost entirely inside the frame 6 viewed from the front. Since the size is accommodated, the electrodynamic speaker 1 can be elongated. The magnetic circuit 10 is not limited to the configuration of this embodiment as long as it forms a linear magnetic gap 14.

  In the electrodynamic speaker 1 of the present embodiment, the coil 4 includes a track-shaped linear portion 4 a disposed in the linear magnetic gap 14 of the magnetic circuit 10, and the other linear portion 4 b of the speaker diaphragm 2. Connect to the center. In the present embodiment, the two coils 41 and 42 and 43 to be bonded together constituting the coil 4 are bonded to each other (for example, one linear portion 4a of the coil 41 and one linear portion 4a of the coil 42 and the coil 3). Are connected in series so that the audio signal currents flow in the same direction. Of course, the coils 41 and 42 and 43 may be connected in parallel. In addition, the tinsel wire (not shown) connected to the coil 4 is electrically connected to the coil 4 by soldering a terminal (not shown) fixed to the frame 6 and a lead wire of the coil 4 from the terminal. Supply current. However, the tinsel wire may be electrically connected to the terminal by providing a metal eyelet on the speaker diaphragm 2.

  When an audio signal current is supplied to the coil 4 in the electrodynamic speaker 1, a driving force acts on one linear portion 4 a of the coil 4 disposed in the linear magnetic gap 14 of the magnetic circuit 10. The coil 4 includes the reinforcing plate portion 5a of the damper 5 that is engaged between the one linear portion 4a and the other linear portion 4b, thereby reinforcing the coils 41, 42, and 43 to increase rigidity. It has been. Therefore, the driving force acting on the portion (one linear portion 4 a of the coil 4) disposed in the magnetic gap 14 of the magnetic circuit 10 of the coil 4 is applied to the speaker diaphragm 2 connected to the other linear portion 4 b of the coil 4. Well communicated. As a result, the electrodynamic speaker 1 using this coil 4 can secure a wide audio reproduction band by increasing the high frequency limit frequency. Further, since the reinforcing plate portion 5a of the damper 5 can be realized with the minimum volume accommodated in the inner circumferential space 4f of the coil 4, it can be reduced in weight, and the linear shape suitable for the thickness dimension 4t of the coil 4 can be obtained. It is not necessary to make it wider than the magnetic gap size, and a high magnetic flux density can be maintained. Further, since the damper 5 has a structure that supports substantially the center of the track-shaped coil 4, the coil 4 can be favorably held in the center with respect to the magnetic gap 14 of the magnetic circuit 10.

  Specifically, the central track-shaped coil 41 constituting the coil 4 has about 18 turns, and the inner circumferential space 4f defined between one straight line portion 4a and the other straight line portion 4b. The dimension 41r of the inner peripheral end, which is the distance in the minor axis direction, is about 3.32 mm. The track-shaped coils 42 and 43 have a winding number of about 16 turns, and are the distance in the minor axis direction of the inner circumferential space 4f defined between one linear portion 4a and the other linear portion 4b. The dimension 42r of the inner peripheral end is about 3.8 mm, and the inner diameters 42r to 43r of the inner peripheral ends of the coils 42 and 43 are larger than the inner diameter 41r of the inner peripheral end of the coil 41. The coils 42 and 43 are formed by reducing the number of windings at the inner peripheral end of a flat air-core coil having the same number of turns as the coil 41 by three turns. As a result, in the coil 4 of this embodiment, the inner peripheral end portion 4e formed by bonding the coils 41, 42 and 43 includes an engagement step portion with which a reinforcing plate portion 5a of the damper 5 described later is engaged. Formed as follows.

  That is, the engagement step portion of the inner peripheral end portion 4e of the coil 4 is formed by a difference in the inner diameter dimensions 41r, 42r, and 43r of the inner peripheral end portions of the coils 41, 42, and 43 to be bonded together. When the coils 41, 42, and 43 are formed using coils having the same number of turns, the windings at the inner peripheral ends of the coils 42 and 43 may be rewound so as to be reduced by one turn or more. Therefore, as illustrated in FIGS. 3 and 4, the reinforcing plate portion 5 a constituting the damper 5 of this embodiment is engaged with the inner peripheral end portion 4 e including the engaging step portion of the coil 4. That is, the outer peripheral end portion 5e of the reinforcing plate portion 5a of the damper 5 includes the coil end surface of the innermost winding of the coil 41 and the inner peripheral surface of the innermost winding of the coils 42 and 43. Engage with.

  Further, the reinforcing plate portion 5a of the damper 5 can be realized with a minimum volume accommodated in the inner circumferential space 4f of the coil 4 by using a part of the damper 5 constituting the vibration system, and thus can be reduced in weight. In addition, it is not necessary to make the size larger than the linear magnetic gap size suitable for the thickness dimension 4t of the coil 4, and a high magnetic flux density can be maintained. The reinforcing plate portion 5a of the damper 5 of the present embodiment is a rectangular flat plate that can be easily processed, but a through hole or a meat stealer may be provided to reduce the weight. Therefore, it is possible to increase the sound reproduction efficiency and to make the electrodynamic speaker 1 having excellent sound reproduction ability. Since the electrodynamic speaker 1 can increase the rigidity of the coil 4, the high frequency limit frequency can be increased to ensure a wide audio reproduction band. Further, since the reinforcing plate portion 5a is provided on the damper 5 constituting the vibration system and supported so as to be able to vibrate at the substantially central position of the coil 4, rolling of the coil 4 can be suppressed.

  The electrodynamic speaker of the present invention can be applied not only as a speaker built in video / audio equipment such as a display but also to a game machine having a cabinet with a built-in speaker for reproducing sound, a game machine such as a slot machine, etc. It is. In addition, the electrodynamic speaker provided with the magnetic circuit for a speaker according to the present invention has a narrow overall width and can realize a speaker system that reproduces sound in a small and thin cabinet. Suitable.

DESCRIPTION OF SYMBOLS 1 Electrodynamic type speaker 2 Speaker diaphragm 3 Edge 4, 41, 42, 43 Coil 5 Damper 51, 52 Damper member 6 Frame 10 Magnetic circuit 11, 12 Yoke 13 Magnet

Claims (6)

The first coil, the second coil, and the third coil, which are flat-plate air-core coils in which a rectangular wire is wound in a multi-layered manner without being shifted from the winding axis, A voice coil that is formed by bonding together and the first coil, the second coil, and the third coil that are bonded together are connected in series or in parallel so that an audio signal current flows in the same direction. When,
A speaker diaphragm coupled to the voice coil;
A magnetic circuit having a linear magnetic gap in which the voice coil is disposed;
A frame coupled to the magnetic circuit;
An edge for fixing the outer peripheral end of the frame to the frame and supporting the outer peripheral end of the speaker diaphragm;
The voice coil formed by bonding the first coil, the second coil, and the third coil is accommodated in an inner circumferential space defined by the inner circumferential end, and the outer circumferential end is the inner circumferential end. A damper having a reinforcing plate portion engaged with the portion, and a movable portion extending from the reinforcing plate portion so as to vibrate and connected to the frame or the magnetic circuit,
Electrodynamic type speaker with The damper is constituted by a set of two damper members arranged in a direction along the winding axis of the voice coil, and each of the damper members is defined by the inner peripheral end of the voice coil. The reinforcing plate portion that is accommodated in the inner peripheral space and the outer peripheral end portion of which engages with the inner peripheral end portion, and extends from the reinforcing plate portion so as to vibrate and is connected to the frame or the magnetic circuit. The movable part,
The thickness of the reinforcing plate portion of the two superimposed damper members is smaller than the voice coil thickness dimension defined by the thickness of the first coil, the second coil, and the third coil bonded together.
The electrodynamic speaker according to claim 1. The inner peripheral ends of the second coil and the third coil sandwiching the first coil have inner diameters larger than the inner diameter of the inner peripheral end of the first coil, and the first coil The inner peripheral end portion of the voice coil formed by bonding the coil and the second coil and the third coil includes an engagement step portion with which the reinforcing plate portion of the damper is engaged.
The electrodynamic speaker according to claim 1 or 2. The second coil and the third coil are formed by reducing the number of turns at the inner peripheral end of a flat-plate air-core coil having the same number of turns as the first coil by one turn or more, and the second coil and the third coil The inner peripheral end of the third coil is configured to have an inner diameter larger than the inner diameter of the inner peripheral end of the first coil.
The electrodynamic speaker according to claim 3. The reinforcing plate portion of the damper includes an engaging step portion that engages with the engaging step portion of the inner peripheral end portion of the voice coil at the outer peripheral end portion thereof.
The electrodynamic speaker according to claim 3 or 4. The first coil, the second coil, and the third coil are formed in one of a track shape including a set of linear portions and a set of arc portions, or a rectangular shape including two sets of linear portions. The outer peripheral end of the reinforcing plate portion of the damper includes at least a set of straight portions that engage with the set of straight portions of the first coil, the second coil, and the third coil.
The electrodynamic speaker according to any one of claims 1 to 5.

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