JP5311053B2 - Electrodynamic speaker - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin and long electrodynamic speaker which has a minor axis direction shorter than a major axis direction, is excellent in sound reproducing capability, and is suitably attached to an apparatus such as a display, regarding the electrodynamic speaker using a planar coil having a winding shaft direction orthogonal to the vibrating direction of a speaker diaphragm. <P>SOLUTION: The electrodynamic speaker is equipped with: a first diaphragm arranged on the front surface side for emitting sound waves; a second diaphragm arranged on the back surface side of the first diaphragm and connected with the outer circumferential side of the first diaphragm on its outer circumferential side; a voice coil which includes the planar coil for which a rectangular wire is wound in multiple layers without shifting it relative to a winding shaft, and is arranged so that the direction of the winding shaft of the coil is orthogonal to the vibrating direction of the first diaphragm and the second diaphragm, and to which the inner peripheral side of the first diaphragm and the inner peripheral side of the second diaphragm are separately connected; and a magnetic circuit having a linear magnetic gap where the voice coil is arranged. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an elongated electrodynamic speaker having a shorter minor axis direction than a major axis direction, and relates to an electrodynamic speaker 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, 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.

  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 speaker of the present invention includes a first diaphragm having a flat plate shape or a substantially cone shape disposed on the front surface side that emits sound waves, and a first vibration disposed on the rear surface side of the first diaphragm. A substantially cone-shaped second diaphragm connected to the outer peripheral side of the plate, and a flat coil in which a flat wire is wound in multiple layers without shifting the rectangular wire with respect to the winding axis, the direction of the winding axis of the coil being the first diaphragm And a voice coil disposed so as to be orthogonal to the vibration direction of the second diaphragm, and the inner peripheral side of the first diaphragm and the inner peripheral side of the second diaphragm being separated from each other and a voice coil are disposed. A magnetic circuit having a linear magnetic gap, wherein the first diaphragm defines a convex ridge line portion on the front side, and the voice coil engages with a part of the back side of the ridge line portion. 1st rib which prescribes | regulates a joint recessed part, and a 2nd diaphragm is convex on the front side or the back side. It defines a line portion, and has a second rib which includes an engaging hole engaging with the voice coil penetrates a part of the ridge portion.

  Preferably, in the electrodynamic speaker according to the present invention, the voice coil includes a first straight part, a second straight part formed in parallel with the first straight part, a first straight part, and a second straight part. An engagement recess of the first diaphragm and an engagement hole of the second diaphragm are respectively formed on the voice coil. The second linear portion of the voice coil is disposed in the linear magnetic gap of the magnetic circuit.

  Preferably, in the electrodynamic speaker according to the present invention, the voice coil includes a first straight part, a second straight part formed in parallel with the first straight part, a first straight part, and a second straight part. An engagement recess of the first diaphragm is connected to the first linear portion of the voice coil, and the second vibration is formed in either a track shape or a rectangular shape including a pair of connection portions connected in a ring shape. The engagement holes of the plate are respectively connected to a set of connecting parts of the voice coil, and the second straight part of the voice coil is arranged in the linear magnetic gap of the magnetic circuit.

  Preferably, in the electrodynamic speaker according to the present invention, the voice coil includes a first straight part, a second straight part formed in parallel with the first straight part, a first straight part, and a second straight part. A track-shaped or rectangular shape including a pair of connecting portions that are connected in a ring shape, accommodated in an inner peripheral space defined by the inner peripheral end portion thereof, and an outer peripheral end portion of the inner peripheral end portion. A reinforcing plate that engages with the end portion is further provided. The engaging concave portion of the first diaphragm is connected to the first linear portion of the voice coil, and the engaging hole portion of the second diaphragm is connected to the reinforcing plate of the voice coil. Connected, the second linear portion of the voice coil is disposed in the linear magnetic gap of the magnetic circuit.

  More preferably, in the electrodynamic speaker of the present invention, the first rib of the first diaphragm and the second rib of the second diaphragm vibrate the direction of the winding axis of the voice coil and the voice coil. The direction is perpendicular to the direction.

  The electrodynamic speaker of the present invention includes a frame connected to the magnetic circuit, an outer peripheral part connected to the frame, an inner peripheral part connected to the outer peripheral side of the first diaphragm or the second diaphragm, and an outer peripheral part. And an edge having a support movable part defined between the inner peripheral part and the inner peripheral part.

  Preferably, the electrodynamic speaker of the present invention further includes a damper having an inner peripheral portion connected to the voice coil and an outer peripheral portion connected to a frame or a magnetic circuit.

  The operation of the present invention will be described below.

  The electrodynamic speaker of the present invention includes a first diaphragm having a flat plate shape or a substantially cone shape disposed on the front surface side that emits sound waves, and a first vibration disposed on the rear surface side of the first diaphragm. A substantially cone-shaped second diaphragm coupled to the outer peripheral side of the plate. The electrodynamic speaker of the present invention includes a flat air core coil in which a flat wire is wound in multiple layers without shifting the rectangular wire with respect to the winding axis, and the direction of the winding axis of the coil is the first diaphragm and the second. A voice coil that is arranged so as to be orthogonal to the vibration direction of the diaphragm and that is connected to the inner peripheral side of the first diaphragm and the inner peripheral side of the second diaphragm, and a linear shape in which the voice coil is disposed An electrodynamic speaker comprising a magnetic circuit having a magnetic gap. That is, the electrodynamic speaker of the present invention has a speaker diaphragm having a double diaphragm structure including a first diaphragm and a second diaphragm, and has a flat plate shape having a winding axis direction perpendicular to the vibration direction. This is an electrodynamic loudspeaker that uses coils.

  The first diaphragm on the front surface side is a flat plate or substantially cone-shaped diaphragm disposed on the front surface side, defining a convex ridge line portion on the front surface side, and a part on the back side of the ridge line portion Has a first rib for defining an engaging recess with which the voice coil is engaged. The second diaphragm on the back side is a substantially cone-shaped diaphragm that defines a convex ridge line part on the front side or the back side, and a voice coil penetrates and engages part of the ridge line part. And a second rib including an engaging hole portion. The voice coil includes a first straight portion, a second straight portion formed in parallel with the first straight portion, and a set of connecting portions that connect the first straight portion and the second straight portion in a ring shape. It is formed into either a track shape or a rectangular shape. Since the engaging recess of the first diaphragm and the engaging hole of the second diaphragm are connected to the first linear portion of the voice coil so as to be separated from each other, as a result, in the direction parallel to the winding axis direction of the voice coil. A loudspeaker vibration system is formed that is a solid structure with a substantially triangular cross section. Further, the first rib of the first diaphragm and the second rib of the second diaphragm are orthogonal to the direction of the winding axis of the voice coil and the direction of vibration of the voice coil, that is, the voice coil. In the case where it is formed in the extending direction of the straight portion, the rigidity in the direction in which these ribs extend can be increased to realize a strong speaker diaphragm having a double diaphragm structure.

  Further, since the second linear portion of the voice coil is disposed in the linear magnetic gap of the magnetic circuit, when an audio signal current is supplied to the voice coil, a driving force acts on the second linear portion of the voice coil. Then, the speaker diaphragm having a double diaphragm structure is vibrated. Therefore, if the direction in which the linear portion of the voice coil and the rib provided on the diaphragm extend is the major axis direction, and the direction parallel to the winding axis direction of the voice coil is the minor axis direction, the major axis direction suitable for mounting on a display or other device Compared to the above, it is possible to realize a slender electrodynamic speaker having a shorter minor axis direction. The electrodynamic speaker of the present invention includes a speaker diaphragm connected to a voice coil, a frame connected to a magnetic circuit, and an edge that supports the outer peripheral end of the speaker diaphragm by fixing the outer peripheral end to the frame. Preferably, a damper having an inner peripheral portion connected to the voice coil and an outer peripheral portion connected to a frame or a magnetic circuit is provided.

  Of course, the engaging recess of the first diaphragm is connected to the first linear portion of the voice coil, while the engaging hole of the second diaphragm is connected to a set of connecting portions of the voice coil. Good. In addition, the voice coil includes a first straight portion, a second straight portion formed in parallel with the first straight portion, and a set of connecting portions that connect the first straight portion and the second straight portion in a ring shape. And a reinforcing plate that is formed in either a track shape or a rectangular shape that is contained in an inner peripheral space defined by the inner peripheral end portion thereof, and the outer peripheral end portion engages with the inner peripheral end portion. May be. By providing this reinforcing plate, the rigidity of the speaker vibration system including the voice coil can be increased, and the driving force acting on the portion of the magnetic circuit of the voice coil that is disposed in the magnetic gap is connected to the voice coil. Fully transmit the driving force to As a result, the electrodynamic speaker using this voice coil can secure a wide audio reproduction band by increasing the high frequency limit frequency. The reinforcing plate may be made of resin or non-magnetic metal and accommodated in the inner space, and the speaker vibration system can be reduced in weight and the magnetic gap can be narrowed. The magnetic flux density in the air gap is increased, and the regeneration efficiency can be further improved.

  The second diaphragm may be a diaphragm having higher rigidity than the first diaphragm. Specifically, the first diaphragm is a speaker diaphragm in which a base is formed by impregnating a base material including a woven or nonwoven fabric made of fibers with a thermosetting resin containing an unsaturated polyester resin, or a paper A speaker diaphragm in which a substrate based on a paper material formed by making fibers is formed, and preferably a silk fiber made of any of plain weave, twill (oblique), satin (weaver), or A surface material including a woven fabric of polyethylene naphthalate fiber is further provided on the front side. Similarly to the first diaphragm, the second diaphragm is a speaker diaphragm in which a base material is formed by impregnating a base material including a woven or nonwoven fabric made of fibers with a thermosetting resin containing an unsaturated polyester resin. Any speaker diaphragm may be used. Preferably, the speaker vibration plate may be formed by forming a base made of a paper material obtained by making a paper fiber and forming it.

  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. This is an elongate electrodynamic speaker with a short coil direction shorter than the major axis direction, which has excellent sound reproduction capability and is suitable for mounting on devices such as displays, and electrodynamics. Type speakers can be provided.

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 structure of the 1st diaphragm 21 and the voice coil 4 by preferable embodiment of this invention. Example 1 It is a figure explaining the structure of the 2nd diaphragm 22 and the voice coil 4 by preferable embodiment of this invention. Example 1 It is a figure explaining the structure of the voice coil 4 by preferable embodiment of this invention. Example 1 It is a figure explaining the structure of the speaker diaphragm 2, the voice coil 4, and the damper 5 by preferable embodiment of this invention. Example 1 It is sectional drawing explaining the electrodynamic type speaker 100 of a comparative example. (Comparative Example 1) It is a partially expanded sectional view explaining the structure of the electrodynamic speaker 100 of a comparative example. (Comparative Example 1) It is a graph of the sound pressure frequency characteristic of the electrodynamic speaker 1 of Example 1 and the electrodynamic speaker 100 of a comparative example. (Example 1, Comparative Example 1) It is a graph of the sound pressure frequency characteristic of the electrodynamic speaker 1a of Example 1 and the electrodynamic speaker 100a of a comparative example. (Example 2, comparative example 2)

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

1 and 2 are diagrams illustrating an electrodynamic speaker 1 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. FIGS. 3 and 4 are diagrams for explaining the configurations of the first diaphragm 21 and the voice coil 4, and the second diaphragm 22 and the voice coil 4, respectively. It is shown. Specifically, FIG. 3A and FIG. 4A are front views, FIG. 3B and FIG. 4B are cross-sectional views in the major axis direction, and FIG. 3C and FIG. (C) is a cross-sectional view in the minor axis direction. Further, FIG. 5 is a diagram illustrating the voice coil 4. 5A is a side view of the voice coil 4 viewed from the minor axis direction, FIG. 5B is a cross-sectional view taken along the line CC ′ of the voice coil 4, and FIG. FIG. 5D is a development view illustrating the configuration of the voice coil 4. Further, FIG. 6 is a diagram for explaining the configuration of the speaker diaphragm 2, the voice coil 4, and the damper 5. FIG. 6A is a side view seen from the major axis direction, and FIG. 6B is a perspective view. As will be described later, a part of the structure of the electrodynamic speaker 1, the internal structure, and the like are omitted. Further, the direction in which the straight line (long axis) connecting the points A-O-A ′ extends is the major axis direction, and the point B-O-B ′.
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 length L1 of about 135.6 mm and a minor axis direction length L2 of about 10 mm. Even if it is a shape, it is a speaker having a diaphragm area equivalent to a circular diaphragm having a diameter of about 35 mm. 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. The speaker diaphragm 2 is a speaker diaphragm having a double diaphragm structure including a first diaphragm 21 and a second diaphragm 22 as will be described later. 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 is a speaker diaphragm having a double diaphragm structure including a first diaphragm 21 and a second diaphragm 22, and the inner peripheral side of the edge 3 is bonded to the outer peripheral end thereof. It is supported so that it can vibrate. As shown in FIGS. 2 and 3, the first diaphragm 21 is an elongated, substantially cone-shaped diaphragm disposed on the front side that emits sound waves. Further, as shown in FIGS. 2 and 4, the second diaphragm 22 is disposed on the back side of the first diaphragm 21 and has an elongated shape connected to the outer peripheral side of the first diaphragm 21 on the outer peripheral side thereof. It is a substantially cone-shaped diaphragm. One linear portion 4b of a track-shaped coil 4 to be described later is bonded to the central back surface side of the first diaphragm 21 with an adhesive. Further, since the inner peripheral side of the second diaphragm 22 is also separated from the inner peripheral side of the first diaphragm 21 and is adhered to the track-shaped coil 4 with an adhesive, the speaker diaphragm 2 is shown in FIG. The loudspeaker vibration system in which the cross section in the minor axis direction shown in the drawing is a solid structure having a substantially triangular shape is formed.

  The first diaphragm 21 constituting the speaker diaphragm 2 is formed by forming a foamed thermoplastic resin in order to reduce the weight. In the case of the present embodiment, the first diaphragm 21 having irregularities is formed by using the extruded thermoplastic resin foam sheet (specifically, polystyrene paper) by using a vacuum forming method in combination with plug assist molding. Have gained. In other words, the first diaphragm 21 constituting the elongated electrodynamic speaker 1 in which the major axis direction length L1 and the minor axis direction length L2 are remarkably different from each other tends to be noticeable due to the split vibration in the major axis direction. The cross-sectional shape is a cone shape including a substantially U shape, and the shape has rigidity in the major axis direction. The first diaphragm 21 defines a diaphragm surface 21a having a cone-shaped cross section, a convex ridge line portion 21d on the front surface side, and the voice coil 4 is engaged with a part on the back surface side of the ridge line portion 21d. And a first rib 21b that defines an engaging recess 21c. That is, the first rib 21b is a rib formed in the major axis direction of the first diaphragm 21, and forms an engagement recess 21c with which the voice coil 4 is engaged on the central back side, and protrudes on the front side. It is a rib which prescribes | regulates the shape ridgeline part 21d.

  The second diaphragm 22 constituting the speaker diaphragm 2 is a substantially cone-shaped diaphragm having higher rigidity than the first diaphragm 21, and in the case of the present embodiment, specifically, a paper fiber is used. This is a speaker diaphragm in which a base body made of a paper material formed by paper making is formed. The second diaphragm 22 is disposed on the back side of the first diaphragm 21 and is connected to the outer peripheral side of the first diaphragm 21 on the outer peripheral side thereof. Since the second diaphragm 22 is likely to have a significant effect of split vibration in the major axis direction, like the first diaphragm 21 having a substantially cone shape, the cone having a substantially U-shaped section in the minor axis direction. It is made into the shape which has rigidity in a major axis direction so that it may become a shape. The second diaphragm 22 defines a diaphragm surface 22a having a conical section, a convex ridge line portion 22d on the front side or the back side, and the voice coil 4 penetrates a part of the ridge line portion 22d. And a second rib 22b including an engagement hole portion 22c to be engaged. That is, the second rib 22b is a rib formed in the major axis direction of the second diaphragm 22, and forms an engagement hole portion 22c with which the voice coil 4 is engaged on the central back side, and on the back side. It is a rib which prescribes | regulates the convex ridgeline part 22d.

  The first diaphragm 21 may be a flat diaphragm that has a lower overall height than that of a substantially cone shape. The first diaphragm 21 is a speaker diaphragm in which a base material is formed by impregnating a base material including a woven or nonwoven fabric made of fibers with a thermosetting resin containing an unsaturated polyester resin, or paper fibers are made from paper. It may be a speaker diaphragm in which a base made of a paper material formed in this way is formed. Preferably, a surface material including a woven fabric of silk fibers or polyethylene naphthalate fibers made of any one of plain weave, twill (oblique) weave and satin (weaver) weave may be further provided on the front side. Further, the substantially corn-shaped second diaphragm 22 may be formed by forming a foamed thermoplastic resin in the same manner as the first diaphragm 21, and a base including a woven fabric or a nonwoven fabric made of fibers. Any speaker diaphragm may be used as long as the base is molded by impregnating the material with a thermosetting resin containing an unsaturated polyester resin.

  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. In the case of the present embodiment, the edge 3 is connected to the back side of the second diaphragm 22 constituting the speaker diaphragm 2 having a double diaphragm structure on the inner peripheral end side. 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. .

  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 of 4 t of about 0.5 mm. More specifically, the coil 4 is formed by winding a copper rectangular wire having a thickness dimension of 0.12 mm × 0.20 mm into a multilayer winding without shifting the winding axis, and the thickness (41t to 42t) is the thickness of the rectangular wire. It includes two air-core coils 41 and 42 formed in a flat plate shape having a dimension approximately equal to about 0.25 mm and a winding layer thickness of about 2.3 mm, and a reinforcing plate 43 described later. The coils 41 and 42 constituting the coil 4 of this embodiment are coils having the same number of turns. The coil 4 is formed by bonding the coil end surfaces with an adhesive (or varnish) so that the winding axes of the coils 41 and 42 coincide with each other, and the bonded coils 41 and 42 are voiced in the same direction. It is a voice coil configured to be connected in series so that a signal current flows. Since the coils 41 and 42 are wound in multiple layers without shifting the rectangular wire with respect to the winding axis, there is a problem that each of the coils 41 and 42 is easily warped and deformed. It can prevent and keep a flat plate shape.

  In the track-shaped coil 4 to which the coils 41 and 42 are bonded, one linear portion 4a, the other linear portion 4b, one arc portion 4c, and the other arc portion 4d are formed to form a track shape. An inner peripheral space 4f which is a track-shaped hole is formed on the inner peripheral side of the inner peripheral end 4e. Therefore, in the coil 4, the outer peripheral end 43e of the reinforcing plate 43 accommodated in the inner peripheral space 4f is engaged with the track-shaped inner peripheral end 4e. The reinforcing plate 43 has an outer peripheral end 43e engaged with the track-shaped inner peripheral end 4e of the coil 4 and is bonded with an adhesive. That is, the outer peripheral end 43 e of the reinforcing plate 43 engages with the inner peripheral surface of the innermost winding of the coils 41 and 42. The reinforcing plate 43 of this embodiment is an aluminum plate having a thickness 43t of about 0.4 mm, and has a track shape with a major axis length of about 31.5 mm and a minor axis length of about 3.5 mm. Since the thickness 43t of the reinforcing plate 43 is made smaller than the voice coil thickness dimension 4t defined by the thickness of the coils 41 and 42 bonded together, the reinforcing plate 43 does not protrude from the inner peripheral space 4f of the coil 4. Since the reinforcing plate 43 increases the rigidity of the coil 4, it suppresses deformation that causes the flat coil 4 to warp. The reinforcing plate 43 may be made of a nonmagnetic metal such as copper, duralumin, or an aluminum alloy, but may be made of a resin such as ABS, PI, or PET. Further, the shape of the reinforcing plate 43 is not limited to a flat plate shape as in the present embodiment.

  The damper 5 is provided with a notch portion (slit portion) in a thin resin plate, and connects the inner fixing portion connected to the coil 4, the outer fixing portion connected to the frame 6, and the inner fixing portion and the outer fixing portion. And an arm-shaped movable part. Specifically, the damper 5 is a member formed by pressing a PC resin plate having a thickness of about 0.2 mm. The inner fixing portion includes an arc portion 4c to an arc portion 4d of the coil 4 and a coil. The four reinforcing plates 43 are inserted and fixed. The damper 5 is connected to the coil 4 or the frame 6 by an adhesive. The damper 5 may be a damper formed by injection molding of a resin, or may be formed by impregnating a phenol resin with a flexible fiber woven fabric as a base material.

  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 that form a linear magnetic gap 14, and a bar-shaped magnet 13 having a rectangular cross section sandwiched between the yokes 11 and 12. 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 31.0 mm and a minor axis direction length of about 5.7 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 loudspeaker 1 of the present embodiment, the coil 4 has a track-shaped linear portion 4a disposed in the linear magnetic gap 14 of the magnetic circuit 10, and the other linear portion 4b has a double diaphragm structure. It connects with the engagement recessed part 21c of the center part of the 1st diaphragm 21 which comprises the speaker diaphragm 2 of this. Further, as shown in FIG. 6, the second diaphragm constituting the speaker diaphragm 2 having a double diaphragm structure is provided on one arc portion 4 c and the other arc portion 4 d of the coil 4 and the reinforcing plate 43. The engagement hole 22c at the center of 22 and the slit of the inner fixing part of the damper 5 are connected. In the present embodiment, the two coils 41 and 42 to be bonded together constituting the coil 4 are mutually the same as the bonded portions (for example, one linear portion 4a of the coil 41 and one linear portion 4a of the coil 42). They are connected in series so that the audio signal current flows in the direction. Of course, the coils 41 and 42 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 43 that is engaged between the one linear portion 4a and the other linear portion 4b, thereby reinforcing the coils 41 and 42 and increasing the rigidity. The reinforcing plate 43 is made of resin or non-magnetic metal and can be realized with a minimum volume accommodated in the inner circumferential space, so that the weight can be reduced, and the linear shape suitable for the thickness dimension 4t of the coil 4 It is not necessary to make it wider than the magnetic gap size, and a high magnetic flux density can be maintained. The reinforcing plate 43 of the present embodiment is a track-shaped flat plate that can be easily processed, but may be lightened by providing a through hole or a meat stealer. Therefore, it is possible to increase the sound reproduction efficiency and to make the electrodynamic speaker 1 having excellent sound reproduction ability.

  In the speaker diaphragm 2 having a double diaphragm structure, the first diaphragm 21, the second diaphragm 22, and the coil 4 together constitute a strong structure having a substantially triangular cross section in the minor axis direction. The damper 5 supports this so as to vibrate. In addition, the first rib 21b of the first diaphragm 21 and the second rib 22b of the second diaphragm 22 are orthogonal to the direction of the winding axis of the coil 4 and the direction in which the coil 4 vibrates. Since it is formed in a certain major axis direction, the rigidity in the direction in which these ribs 21b and 22b extend can be increased, and the speaker diaphragm 2 having a strong double diaphragm structure can be realized. 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.

  FIG. 7 and FIG. 8 are diagrams illustrating an electrodynamic speaker 100 of a comparative example corresponding to the electrodynamic speaker 1 of the previous embodiment. Specifically, FIG. 7 is a perspective view of the electrodynamic speaker 100, and FIG. 8 is a partially enlarged view of a cross section in the minor axis direction of the electrodynamic speaker 100 of the comparative example. That is, the electrodynamic speaker 100 of the comparative example is composed of only the cone-shaped speaker diaphragm 20 as compared with the speaker diaphragm 2 having the double diaphragm structure of the previous embodiment, and is not a double diaphragm structure. It is different in that. Therefore, common portions are denoted by common numbers and description thereof is omitted.

  The speaker diaphragm 20 of the comparative example has the same configuration as that of the first diaphragm 21 of the previous embodiment, and an extruded thermoplastic resin foam sheet (specifically, polystyrene paper) is plug-assist-molded. By using a vacuum forming method in combination with the above, a diaphragm having irregularities is obtained. In other words, the speaker diaphragm 20 constituting the elongated electrodynamic speaker 100 of the comparative example is prone to the influence of the divided vibration in the major axis direction, so that the sectional shape in the minor axis direction has a cone shape including a substantially U shape. In this way, the shape has rigidity in the major axis direction. Similarly to the first diaphragm 21 of the previous embodiment, the speaker diaphragm 20 defines a diaphragm surface having a cone shape in cross section, a convex ridge line portion on the front side, and the back side of the ridge line portion. And a rib for defining an engagement recess with which the coil 4 is engaged.

  FIG. 9 is a graph of sound pressure frequency characteristics of the electrodynamic speaker 1 including the speaker diaphragm 2 having the double diaphragm structure of the example and the electrodynamic speaker 100 using the speaker diaphragm 20 of the comparative example. As shown by the solid line in FIG. 9, the electrodynamic speaker 1 using the speaker diaphragm 2 having the double diaphragm structure of the embodiment can secure a wide audio reproduction band by increasing the high frequency limit frequency. On the other hand, as shown by the broken line, in the electrodynamic speaker 100 using the speaker diaphragm 20 of the comparative example, the high frequency limit frequency is lowered, a high peak is generated around 4 kHz, and a wide audio reproduction band is secured. I can't.

  In the speaker diaphragm 2 of the embodiment, the first diaphragm 21, the second diaphragm 22, and the coil 4 realize a double diaphragm structure in which a strong structure is formed, and the coil 4 is a reinforcing plate 43. The structure of the vibration system including the speaker diaphragm 2 is stabilized. As a result, even if the electrodynamic speaker 1 of this embodiment is an elongated electrodynamic speaker in which the vibration system operation is likely to be unstable, the coil 4 is in contact with the magnetic gap 14 of the magnetic circuit 10. It is possible to suppress problems that cause abnormal noise and cause malfunction.

  The second diaphragm 22 constituting the speaker diaphragm 2 having a double diaphragm structure may have an engaging hole 22 c at the center connected to the other straight portion 4 b of the coil 4. That is, the engagement recess 21 c of the first diaphragm 21 and the engagement hole 22 c of the second diaphragm 22 may be connected to the linear portion 4 b of the coil 4 separately from each other. The engagement hole portion 22 of the second diaphragm 22 is separated from the engagement recess 21 c in the other linear portion 4 b of the coil 4 to which the engagement recess 21 c at the center of the first diaphragm 21 is connected. If connected, it is possible to realize a double diaphragm structure in which the cross section in the minor axis direction is a strong triangular structure.

  Further, the second diaphragm 22 may be configured such that the engagement hole 22 c at the center thereof is connected to one of the arc part 4 c and the other arc part 4 d of the coil 4 and the reinforcing plate 43. If the engagement hole 22 of the second diaphragm 22 is connected to the coil 4 so as to be separated from the engagement recess 21c at the center of the first diaphragm 21, as in the previous case, It is possible to realize a double diaphragm structure that is a strong structure having a substantially triangular cross section.

  Moreover, in the coil 4 of an Example, the reinforcement board 43 is formed in the track shape corresponding to the track shape of the inner peripheral edge part 4e of a coil. However, the reinforcing plate 43 may have a rectangular shape that connects one linear portion 4a of the track shape and the other linear portion 4b. The reinforcing plate 43 may have another shape corresponding to the shape of the inner peripheral end portion of the coil. For example, when the coil is rectangular, the reinforcing plate that further improves the rigidity may be rectangular.

  In the electrodynamic speaker 1, the flat coil 4 is supported by the integrally formed damper 5 so as to be able to vibrate, but may be a damper 5 of another form. The damper 5 may be connected to one of the arc portion 4 c and the other arc portion 4 d of the coil 4 and the reinforcing plate 43. For example, the damper 5 may support the end of the coil 4 in the major axis direction so as to be able to vibrate by other forms of dampers 51 and 52, and the damper 5 can suppress the rolling of the coil 4. It is not necessary to prepare.

  FIG. 10 shows the sound of the electrodynamic speaker 1a (not shown) including the speaker diaphragm 2 having the double diaphragm structure of the embodiment and the electrodynamic speaker 100a (not shown) using the speaker diaphragm 20 of the comparative example. It is a graph of a pressure frequency characteristic. The electrodynamic speaker 1a of the present embodiment is a case where a coil 40 (not shown) that does not include the reinforcing plate 43 is used instead of the coil 4 of the electrodynamic speaker 1 of the previous embodiment. In the point provided with the speaker diaphragm 2 having a diaphragm structure, it is common to the electrodynamic speaker 1 of the previous embodiment. Similarly, the electrodynamic speaker 100a of the comparative example 2 is a case where the coil 40 not provided with the reinforcing plate 43 is used instead of the coil 4 of the electrodynamic speaker 100 of the above comparative example. There is no diaphragm structure. Therefore, common portions are denoted by common numbers and description thereof is omitted.

  In the coil 40 that does not include the reinforcing plate 43 that increases the rigidity, an inner peripheral space 4f that is a track-shaped hole is formed on the inner peripheral side of the track-shaped inner peripheral end 4e. As a result, in the electrodynamic speaker using this coil 40, the driving force acting on the linear portion 4 a arranged in the magnetic gap 14 of the magnetic circuit 10 of the coil 40 is compared with the case of the coil 4 including the reinforcing plate 43. Thus, it is not sufficiently transmitted to the speaker diaphragm 2 connected to the other linear portion 4b of the coil 40.

  However, as shown by the solid line in FIG. 10, the electrodynamic speaker 1a using the speaker diaphragm 2 having the double diaphragm structure according to the second embodiment uses the coil 40 that does not include the reinforcing plate 43. Although the peak in the vicinity of about 9 kHz tends to be larger than that of the electrodynamic speaker 1 of the example, it is possible to secure a wide sound reproduction band by increasing the high frequency limit frequency as compared with the comparative example 2. On the other hand, as shown by a broken line, in the electrodynamic speaker 100a using the speaker diaphragm 20 of Comparative Example 2, since the coil 40 without the reinforcing plate 43 is used, a high peak is about 4 kHz and a deep is about 6 kHz. Dips occur, and a wide audio reproduction band cannot be secured.

  In the speaker diaphragm 2 according to the second embodiment, since the first diaphragm 21, the second diaphragm 22, and the coil 40 realize a double diaphragm structure that is a strong structure, the coil 40 is a reinforcing plate. Even if 43 is not provided, the structure of the vibration system including the speaker diaphragm 2 is stabilized. This is because the engagement hole 22c at the center of the second diaphragm 22 is connected to one arc part 4c and the other arc part 4d of the coil 4. Of course, the second diaphragm 22 may have the engagement hole 22c at the center thereof connected to the other linear portion 4b of the coil 4. As a result, even if the electrodynamic speaker 1a of the present embodiment is an elongated electrodynamic speaker in which the vibration system operation is likely to be unstable, the coil 40 is in contact with the magnetic gap 14 of the magnetic circuit 10. It is possible to suppress problems that cause abnormal noise and cause malfunction.

  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 1,100 Electrodynamic type speaker 2 Speaker diaphragm 21 First diaphragm 22 Second diaphragm 3 Edge 4, 40 Coil 41, 42 Coil 43 Reinforcement plate 5 Damper 6 Frame 10 Magnetic circuit 11, 12 Yoke 13 Magnet

Claims (7)

A flat plate-like or substantially cone-shaped first diaphragm arranged on the front side that emits sound waves;
A substantially cone-shaped second diaphragm disposed on the back side of the first diaphragm and connected to the outer circumference side of the first diaphragm on the outer circumference side thereof;
A flat coil including a flat wire wound in multiple layers without shifting with respect to the winding axis is included, and the direction of the winding axis of the coil is orthogonal to the vibration direction of the first diaphragm and the second diaphragm. A voice coil that is disposed and that is connected with an inner peripheral side of the first diaphragm and an inner peripheral side of the second diaphragm separated from each other;
A magnetic circuit having a linear magnetic gap in which the voice coil is disposed,
The first diaphragm has a first rib that defines a convex ridge line portion on the front surface side, and an engagement recess that engages the voice coil on a part of the back surface side of the ridge line portion. ,
The second diaphragm includes a second rib that defines a convex ridge line portion on the front surface side or the back surface side, and includes an engagement hole portion through which the voice coil penetrates and engages a part of the ridge line portion. Having
Electrodynamic type speaker. The voice coil includes a first straight portion, a second straight portion formed in parallel with the first straight portion, and a set of connecting portions that connect the first straight portion and the second straight portion in an annular shape. , Formed into either a track shape or a rectangular shape,
The engagement concave portion of the first diaphragm and the engagement hole of the second diaphragm are connected to the first linear portion of the voice coil so as to be separated from each other, and the second linear portion of the voice coil Is arranged in the linear magnetic gap of the magnetic circuit,
The electrodynamic speaker according to claim 1. The voice coil includes a first straight portion, a second straight portion formed in parallel with the first straight portion, and a set of connecting portions that connect the first straight portion and the second straight portion in an annular shape. , Formed into either a track shape or a rectangular shape,
The engaging concave portion of the first diaphragm is connected to the first linear portion of the voice coil, and the engaging hole portion of the second diaphragm is connected to the pair of connecting portions of the voice coil, respectively. Coupled, and the second linear portion of the voice coil is disposed in the linear magnetic gap of the magnetic circuit,
The electrodynamic speaker according to claim 1. The voice coil includes a first straight portion, a second straight portion formed in parallel with the first straight portion, and a set of connecting portions that connect the first straight portion and the second straight portion in an annular shape. , Formed into either a track shape or a rectangular shape,
A reinforcing plate that is accommodated in the inner circumferential space defined by the inner circumferential end portion, and whose outer circumferential end portion engages with the inner circumferential end portion;
The engagement recess of the first diaphragm is connected to the first linear portion of the voice coil, the engagement hole of the second diaphragm is connected to the reinforcing plate of the voice coil, and The second linear portion of the voice coil is disposed in the linear magnetic gap of the magnetic circuit;
The electrodynamic speaker according to claim 1. The first rib of the first diaphragm and the second rib of the second diaphragm are orthogonal to the direction of the winding axis of the voice coil and the direction of vibration of the voice coil. Formed in the
The electrodynamic speaker according to any one of claims 1 to 4. A frame coupled to the magnetic circuit;
An outer peripheral part connected to the frame, an inner peripheral part connected to the outer peripheral side of the first diaphragm or the second diaphragm, and a support movable part defined between the outer peripheral part and the inner peripheral part; An edge having
The electrodynamic speaker according to any one of claims 1 to 5. An inner periphery connected to the voice coil, and an outer periphery further includes a damper connected to the frame or the magnetic circuit;
The electrodynamic speaker according to claim 6.

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