JP2006067112A - Electroacoustic transducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin electroacoustic transducer capable of increasing sound pressure with respect to an electroacoustic transducer to be used for acoustic equipment, video equipment, and information communication equipment, and with respect to a module and electronic equipment and device. <P>SOLUTION: A conductor 20 forming a diaphragm 16 is configured by a product in which at least an insulating layer 22 is formed as a conductor coating around a wire-like conductor core material 21. The conductors 20 are arranged and coupled, thereby configuring the integrated diaphragm 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electroacoustic transducer used for various types of audio equipment, video equipment, and information communication equipment.

  Electroacoustic transducers are often used as mobile phones, stereo sets, electronic devices such as televisions, and mobile devices such as automobiles as sets on which the electroacoustic transducers are mounted.

  These electronic devices have been reduced in size as a recent market trend, and in the field of video such as televisions, there is a demand for thinning unprecedented with the rapid spread of thin televisions such as liquid crystal televisions and plasma display televisions. It has come to be.

  Against the backdrop of such market trends, there are strict market demands for electroacoustic transducers used in these electronic devices and devices to be thin and to have high input resistance that enables large inputs.

  The vibration system of a conventional electroacoustic transducer is composed of a voice coil that inputs a voice electric signal, and a diaphragm that is coupled to the voice coil, receives the vibration of the voice coil, and acoustically converts the vibration. Yes.

  For this reason, the diaphragm and the voice coil are indispensable components for constituting the electroacoustic transducer. In order to reduce the thickness of the electroacoustic transducer, a structure of a flat speaker as shown in FIG. 7 has been proposed.

  FIG. 7 shows the structure of a flat speaker, which is a type of conventional electroacoustic transducer. FIG. 7A is a cross-sectional view taken along the line DD 'in FIGS. 7B and 7C, and FIG. Sectional drawing in the WW 'surface in a), (c) is a top view of a diaphragm.

  In FIG. 7, reference numeral 101 denotes a box-shaped yoke made of iron or the like and one of which is opened. The periphery of the yoke 101 is surrounded by a frame 102 made of a resin material such as non-magnetic polycarbonate.

  Reference numeral 103 denotes a permanent magnet installed on one side of the yoke 101 so that its magnetic axis is vertical. A plate 104 made of iron or the like is placed on the permanent magnet 103 for the purpose of stabilizing the leakage magnetic flux. Yes. A yoke 101, a permanent magnet 103, and a plate 104 constitute a magnetic circuit 105.

  106 is a diaphragm disposed at a predetermined distance from the plate 104, and is supported by a support member 107 made of flexible urethane or the like, so that the diaphragm 106 can swing smoothly up and down. It is configured.

  The diaphragm 106 is configured by adhering and fixing a spiral voice coil 109 formed by winding an aluminum wire or the like on one surface of a film base material 108 made of insulating polyimide or the like.

  With such a configuration, when a current flows through the spiral voice coil 109 in the direction shown in the figure, the spiral voice coil 109 is affected by the leakage magnetic field formed by the magnetic circuit 105, that is, the magnetic flux in the H direction in the figure. On the other hand, because Fleming's left-hand rule receives an electromagnetic force in the direction F, the diaphragm 106 vibrates up and down by the current flowing through the spiral voice coil 109, and a sound is generated.

As prior art document information related to the invention of this application, for example, Patent Document 1 is known.
JP 2001-333493 A

  In this type of conventional speaker, since the voice coil is driven by the leakage magnetic flux, only a small magnetic flux density can be applied to the voice coil, and it has been difficult to achieve a high sound pressure. Accordingly, in order to increase the sound pressure in the conventional flat speaker, it is necessary to increase the self-inductance of the coil itself. However, in order to increase the self-inductance while keeping the impedance constant, the wire diameter of the voice coil itself is increased. It was necessary to increase the number of turns of the coil. For this reason, the voice coil itself increases in thickness and area, resulting in an increase in weight, making it difficult to achieve high sound pressure and thickness reduction.

  In addition, if the weight of the voice coil increases, the adhesive strength per area of the voice coil to the base material decreases, so the vibration of the diaphragm causes displacement and separation of the base material and the voice coil, causing the voice coil to vibrate. It had the subject that it collided with a board and abnormal noise will generate | occur | produce. In addition, poor bonding such as misalignment and peeling is also caused by a decrease in the bonding strength between the voice coil and the base material due to Joule heat generated in the voice coil, and conventional flat speakers have limitations in thinning and high sound pressure. It was a thing.

  The present invention solves the above-described conventional problems, and an object thereof is to provide a thin electroacoustic transducer capable of handling high sound pressure.

  In order to achieve the above object, the present invention comprises forming a diaphragm by forming a conductor as a conductor covering around a wire-shaped conductor core material and forming at least an insulating layer. It is characterized in that it is configured as an integrated diaphragm by arranging and connecting the two.

  According to the present invention, the diaphragm can be formed of only a conductor, and the conductor itself can function as a diaphragm, so that a conventional base material for holding a voice coil is not required. Thus, the weight and thickness can be reduced.

  Further, since there is no deviation or separation between the voice coil and the base material as in the prior art, it is possible to provide an electroacoustic transducer that is thin and capable of handling high sound pressure without vibration transmission loss. In addition, since the number of parts can be reduced, productivity can be improved and costs can be reduced.

(Embodiment 1)
FIG. 1 shows a configuration of a speaker according to Embodiment 1 of the present invention. FIG. 1 (a) is a cross-sectional view taken along the plane AA 'in FIGS. 1 (b) and (c), and FIG. Sectional drawing in the XX 'plane in (c) is a top view of a diaphragm. FIG. 2 is a cross-sectional view of a magnet wire serving as a conductor.

  In FIG. 1, reference numeral 11 denotes a box-shaped yoke made of iron or the like with one side opened. The periphery of the yoke 11 is surrounded by a frame 12 such as a non-magnetic polycarbonate.

  Reference numeral 13 denotes a permanent magnet installed on one side of the yoke 11 so that its magnetic axis is vertical. A plate 14 made of iron or the like is placed on the permanent magnet 13 for the purpose of stabilizing the leakage flux. Yes. The yoke 11, the permanent magnet 13 and the plate 14 constitute a magnetic circuit 15.

  Reference numeral 16 denotes a diaphragm disposed at a predetermined distance from the plate 14 and supported by a support member 17 made of flexible urethane or the like, so that the diaphragm 16 can smoothly swing up and down. It is configured.

  Further, the diaphragm 16 is constituted by a wire-like conductor 20 to which an audio electric signal is inputted, and the conductor 20 is constituted as shown in FIG. That is, in this embodiment, a magnet wire is used as the conductor 20, and this magnet wire has a conductor core material 21 made of aluminum at the center, and an insulating layer made of polyimide or the like as a conductor coating. 22 and the periphery thereof is covered with a fusion layer 23 of polyamide, epoxy, or the like to form a rectangular wire.

  The fusion layer 23 does not necessarily have to be present from the beginning, and may be configured to be applied when the voice coil is formed.

  In the present embodiment, the conductor 20 is wound in a square spiral shape without a gap and is formed in a flat plate shape, and heat is applied to the conductor 20 to fix the adjacent fusion layers 23 to each other. Is used as a substantially flat diaphragm 16 integrated with the above.

  Further, by fixing the winding start portion 18a and the winding end portion 18b of the conductor 20 on the frame 12, it can be used as a terminal (not shown) for inputting an audio electric signal. At this time, it is preferable to use a flexible conductor (not shown) such as a gold thread wire for connecting each of the winding start portion 18a and the winding end portion 18b of the conductor 20 to the terminal. Thereby, the vertical amplitude of the diaphragm 16 can be easily ensured between the diaphragm 16 formed of the conductor 20 and a terminal provided on the frame 12.

  The speaker of the present embodiment configured as described above operates as follows. That is, a magnetic field in the H direction in the figure is generated by the magnetic circuit 15 including the yoke 11, the permanent magnet 13, and the plate 14. In this magnetic field, the electromagnetic force in the F direction is received by Fleming's left-hand rule with respect to the current in the direction shown in the figure. Become.

  As described above, the present embodiment has the following characteristics only by replacing the conventional diaphragm 106 with the diaphragm 16 as shown in FIG.

  First, according to the present embodiment, the diaphragm 16 can be formed of only the conductor 20, and the conductor itself that has served as the voice coil of the conventional speaker can function as the diaphragm. A conventional film base 108 for holding the spiral voice coil 109 is not required, and the weight and thickness can be reduced.

  Further, in the conventional configuration, in principle, a vibration transmission loss is generated between the film base material 108 as the diaphragm 106 and the spiral voice coil 109 as the conductor. However, according to the present embodiment, the film base material 108 is not required. However, according to the present embodiment, the film base 108 is not required. Therefore, joining deviation and peeling do not occur.

  Conventionally, in order to reduce the weight of the diaphragm 106, the spiral voice coil 109 is formed on the film base material 108 in accordance with the magnetic field generation region by the magnetic circuit 105. However, according to the present embodiment, since the conductor 20 is present throughout the diaphragm 16, the vibration mode as the diaphragm 16 can be stabilized. It has become. Thereby, unnecessary resonance in the diaphragm 16 can be eliminated, and sound pressure frequency characteristics and distortion can be improved.

  In addition, according to the present embodiment, compared to the conventional configuration, it is possible to uniformly arrange the conductors 20 without gaps, so that the conductor 20 is placed in a magnetic field with a high space factor, They can be arranged uniformly, improving the conversion efficiency and obtaining a stable vertical amplitude that does not cause rolling. Therefore, it is possible to improve the sound pressure level and reduce distortion.

  Furthermore, by using a magnet wire for the conductor 20, an existing commercial product can be used as the conductor material, and productivity can be improved and costs can be reduced.

  In the present embodiment, aluminum is used for the conductor core material 21 forming the diaphragm 16. However, since the weight of the diaphragm 16 can be reduced by this, high sound pressure and high A speaker suitable for extending the frequency limit can be realized. On the other hand, when copper is used for the conductor core material 21, since the specific resistance is lower than that of aluminum, the sound pressure level is improved by obtaining a large self-inductance for the same impedance value, and the lowest resonance frequency (F0 value). A speaker suitable for extension can be obtained.

  Furthermore, the connection with the gold thread wire and the terminal part is also highly reliable due to the good soldering, the material has a high elastic modulus, and the resistance to disconnection during vibration is further improved. Can be increased.

  Note that both of the above characteristics can be obtained by using a mixture of aluminum and copper for the conductor core material 21.

  That is, it is possible to achieve both the extension of the high frequency limit frequency due to aluminum and the improvement in reliability due to copper.

  Further, since the diaphragm 106 is conventionally formed by forming the spiral voice coil 109 on a flat plate such as the film base material 108, the vibration of the convex or spherical shape, for example, with the structure of the conventional diaphragm. When the plate 106 is to be formed, the spiral voice coil 109 is easily detached from the film substrate 108. According to the present embodiment, the conductor itself can be easily formed into a convex shape or a spherical shape, for example. Therefore, the degree of freedom in designing the shape of the diaphragm is greatly improved.

  In the case where the diaphragm has a cone shape, if the diaphragm 66a is driven as shown in FIG. 6A, the voice coil 69 is always required and the joint portion 68 is necessary. Therefore, the vibration of the voice coil 69 is always transmitted indirectly via the joint portion 68. On the other hand, according to the present embodiment, the diaphragm 66b itself can be formed of a conductor as shown in FIG. 6B, that is, the diaphragm 66b itself functions as a conventional voice coil 69. Therefore, direct driving is possible instead of indirect driving as in the prior art.

  This principle of operation is dealt with by providing a magnetic circuit for causing a leakage magnetic flux in the vicinity of the diaphragm 66b formed of a conductor so that the diaphragm 66b can vibrate. With this configuration, vibration transmission loss can be eliminated, the sound pressure level can be improved, and high-fidelity reproduction can be achieved.

  Further, according to the present embodiment, the magnetic circuit 15 for driving the diaphragm 16 generates a DC magnetic field by the permanent magnet 13, but the same effect can be obtained by generating an induced magnetic field by a DC current instead of this magnetic circuit. An effect is obtained.

(Embodiment 2)
FIG. 3 shows Embodiment 2 of the present invention. 3A is a cross-sectional view taken along the line BB ′ in FIGS. 3B and 3C, FIG. 3B is a cross-sectional view taken along the line YY ′ in FIG. 3A, and FIG. It is a top view.

  A feature of the present embodiment is that four spiral coils 39a to 39d in FIG. 3 (c) are composed of a single conductor 20. That is, in FIG. 3C, the conductor 20 starting from the winding start portion 38a is wound from the outer side to the inner side in the spiral coil 39d, and passes through the lower surface of the spiral coil 39d in the central portion. The spiral coil 39c becomes the central portion of the spiral coil 39c, and is wound outward from the spiral coil 39b. It is wound outward and ends at the end of winding 38b.

  Further, the winding start portion 38a and the winding end portion 38b are fixed on the frame 32 and used as a terminal (not shown) for inputting a sound electric signal.

  The four spiral coils 39a to 39d formed as described above are flattened to form a vibration plate 36, and currents flow in the same direction in adjacent sides of the coils 39a to 39d. It is wound.

  With this configuration, the permanent magnet 33, the yoke 31, and the plate that are installed in the yoke 31 with their magnetic axes perpendicular to each other so that the adjacent magnets are opposite to each other are opposed to the center of each coil. In the magnetic field in the H direction in the figure generated from the magnetic circuit 35 composed of 34, an electromagnetic force in the F direction is received according to Fleming's left-hand rule.

  Due to this configuration, the diaphragm 36 vibrates up and down by the current flowing through the conductor 20, and sounds are generated.

  In the present embodiment, the number of coils of the spiral coils 39a to 39d is increased to four and the magnetic circuit 35 corresponding thereto is configured, thereby increasing the driving force of the diaphragm 36 and improving the sound pressure level. Can be planned.

(Embodiment 3)
FIG. 4 shows Embodiment 3 of the present invention. 4A is a cross-sectional view taken along the CC ′ plane in FIGS. 4B and 4C, FIG. 4B is a cross-sectional view taken along the ZZ ′ plane in FIG. 4A, and FIG. It is a top view.

  The feature of the present embodiment is that the conductors are arranged in a straight line and not in a spiral shape, and accordingly, the magnetic circuit is also configured so that the direction of the magnetic flux is one direction. This is the point.

  In FIG. 4 (c), the diaphragm 46 is formed by arranging a plurality of conductors 20 in a straight line and in parallel with no gap and flattening them. Note that both ends of the conductor 20 are also electrically connected, and the both ends 48a and 48b are fixed on the frame 42 to be used as terminals (not shown) for inputting audio electric signals. Yes.

  The permanent magnet 43 is magnetized so that its magnetic axis is vertical and the adjacent magnets are the same, and a plurality of elongated magnets arranged in the same direction as the conductor 20 are arranged together with the yoke 41 and the plate 44 together with the magnetic circuit 45. Is configured.

  In particular, as shown in FIG. 4A, the plate 44 is arranged in a loop from the permanent magnet 43 and the yoke 41 so that the plate 44 is concentrated in the H direction in the drawing perpendicular to the direction of the conductor 20. A magnetic field can be generated. With respect to the magnetic field in the H direction, the current in the arrow direction in the figure receives an electromagnetic force in the F direction, so that the diaphragm 46 oscillates up and down with respect to the current flowing through the conductor 20 to generate sound.

  In addition, compared to the increase in impedance due to the self-inductance of the spiral coil 109 according to the conventional configuration, according to the present embodiment, the conductors 20 cut to a certain length are connected in parallel, so that the low impedance Conversion efficiency can be improved and power consumption can be reduced.

  In addition, since the winding step of the spiral coil 109 in the diaphragm 106 according to the conventional configuration is not required, productivity can be improved in the present embodiment.

  In the present embodiment, two magnetic circuits are shown in the figure, but by using two or more magnetic circuits, the magnetic field becomes stronger and the sound pressure level is further improved.

  In the present embodiment, the diaphragm 46 is a single-layer conductor 20, but two or more conductors 20 may be used, thereby improving the self-inductance of the coil and further improving the sound pressure level. it can.

  In addition, although a rectangular shape is used in the present embodiment, the same effect can be obtained with a slim shape such as a circular shape, an elliptical shape, or a track shape.

  The same can be said for the first and second embodiments.

(Embodiment 4)
FIG. 5 is a cross-sectional view of a magnet wire that is the conductor 20.

  (A) is sectional drawing of the flat wire used in this Embodiment 1. FIG. Since the central conductor core material 21 has a rectangular cross section, the contact area of the fusion layer 23 serving as a conductor coating is widened to increase the bonding strength and improve the space factor of the conductor core material. The sound pressure level can be improved.

  5B to 5F show other cross-sectional shapes. (B) is circular, and since this shape is the most widely used shape as the magnet wire which is the conductor 20, it is versatile and can reduce costs.

  (C) is a track type, and can be made thinner than (b).

  (D)-(f) are respectively a triangle, a trapezoid, and a rhombus, and while the junction part of conductors is planar, the contact surface is comprised diagonally with respect to the vibration direction as a diaphragm. With this configuration, an effect of being difficult to come off with respect to the vertical amplitude of the diaphragm is exhibited. In other words, if the method of applying force is not equal, or if there is a difference in the method of applying force depending on the location of the diaphragm, shear stress will act in the direction of tearing the diaphragm, and this has the effect of preventing this. is there.

  As described above, the electroacoustic transducer according to the present invention can be applied to electronic devices such as audiovisual equipment and information communication equipment that need to be made thin and high in sound pressure, and further to apparatuses such as automobiles.

(A) Cross-sectional view of the speaker according to Embodiment 1 of the present invention, (b) Cross-sectional view of the speaker according to Embodiment 1 of the present invention, (c) Plan view of the diaphragm of the speaker according to Embodiment 1 of the present invention. Sectional drawing of the magnet wire used for the diaphragm of the speaker in Embodiment 1,2,3 of this invention (A) Cross-sectional view of the speaker in the second embodiment of the present invention, (b) Cross-sectional view of the speaker in the second embodiment of the present invention, (c) Plan view of the diaphragm of the speaker in the second embodiment of the present invention. (A) A cross-sectional view of a speaker according to Embodiment 3 of the present invention, (b) a cross-sectional view of a speaker according to Embodiment 3 of the present invention, and (c) a plan view of a speaker diaphragm according to Embodiment 3 of the present invention. (A)-(f) Sectional drawing of the magnet wire used for the diaphragm of the speaker in Embodiment 1,2,3 of this invention (A) The perspective view in the diaphragm and voice coil of the conventional speaker, (b) The perspective view of the diaphragm in the application example of Embodiment 1 of this invention. (A) Cross-sectional view of a conventional flat speaker, (b) Cross-sectional view of a conventional flat speaker, (c) Plan view of a diaphragm of a conventional flat speaker

Explanation of symbols

11, 31, 41, 101 Yoke 12, 32, 42, 102 Frame 13, 33, 43, 103 Permanent magnet 14, 34, 44, 104 Plate 15, 35, 45, 105 Magnetic circuit 16, 36, 46, 106 Vibration Plate 17, 107 Support member 18a, 38a Winding start portion 18b, 38b Winding end portion 20 Conductor 21 Conductor core material 22 Conductor coating / insulating layer 23 Conductor coating / fusion layer 39a-d Spiral voice coil 48a, 48b Conductor end portions 66a, 66b Diaphragm 68 Joint portion 69 Voice coil 108 Film base 109 Spiral coil

Claims (10)

A diaphragm made of a conductor made of a wire-like conductor core material to which an electric signal is inputted and having an insulating layer formed so as to cover at least the conductor core material, and a magnetic flux for driving the diaphragm An electroacoustic transducer comprising: generating means; and a frame for supporting the diaphragm and the magnetic flux generating means, wherein the diaphragm is integrated by combining adjacent conductors. The electroacoustic transducer according to claim 1, wherein the diaphragm is formed in a substantially planar shape. The electroacoustic transducer according to claim 1, wherein the conductor is formed in a spiral shape. The electroacoustic transducer according to claim 1, wherein the conductor is formed by combining a plurality of linear conductors. The electroacoustic transducer according to claim 1, wherein the conductors are insulated from each other and coupled without gaps. The electroacoustic transducer according to claim 1, wherein the conductor is formed in a substantially planar shape and is laminated in two or more layers. The electroacoustic transducer according to claim 1, wherein the conductor is made of a magnet wire. The electroacoustic transducer according to claim 7, wherein the conductor core material of the magnet wire is made of copper, aluminum, or a mixture of copper and aluminum. The electroacoustic transducer according to claim 7, wherein the cross-sectional shape of the magnet wire is any one of a rectangle, a square, a perfect circle, a track, a triangle, a trapezoid, and a rhombus. The electroacoustic transducer according to claim 1, wherein the magnetic flux generating means uses an induced magnetic field.

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