WO2017145284A1

WO2017145284A1 - Electroacoustic transducer

Info

Publication number: WO2017145284A1
Application number: PCT/JP2016/055410
Authority: WO
Inventors: 昭人花田
Original assignee: 昭人花田
Priority date: 2016-02-24
Filing date: 2016-02-24
Publication date: 2017-08-31
Also published as: JP6667930B2; JPWO2017145284A1

Abstract

The purpose of the present invention is to provide an electroacoustic transducer which adopts a voice coil diaphragm, implements a new vibration mode by utilizing not only a parallel magnetic field component but also a vertical magnetic field component of a magnetic field formed by a magnet plate to achieve further improved performance and diversity, and which has excellent versatility, mass productivity, and resource saving performance. An electroacoustic transducer comprising: a magnet plate; and a coil vibrating body formed by winding a conductor and disposed in front of the magnet plate, wherein the coil vibrating body has a vibration plane inclined with respect to a front surface of the magnet plate or a vibration plane perpendicular to the front surface of the magnet plate, the vibration plane is formed into a loop shape, and the vibration of the coil vibrating body has at least a component parallel to the front surface of the magnet plate, thereby increasing the utilization efficiency of a magnet and greatly improving directional characteristics.

Description

Electroacoustic transducer

The present invention relates to an electroacoustic transducer applied to a speaker, a headphone, an earphone or the like that converts an electric signal into sound, or a microphone or a sound wave sensor that converts received sound into an electric signal.

Conventionally, in an electroacoustic transducer called a gummazone type speaker, a planar coil pattern is formed of a conductor corresponding to a voice coil, and a part for generating a driving force is integrated with a diaphragm (hereinafter referred to as “voice coil vibration”). Plate) is installed in the middle part of the pair of magnetic field generators, and a drive current is supplied to the conductor to vibrate the voice coil diaphragm in a direction perpendicular to the plane. Yes.
The voice coil diaphragm of this Gummazon type speaker has a structure in which conductors are arranged almost over the entire area of the voice coil diaphragm, so that the entire surface is driven in the same phase and good transient characteristics can be obtained over a wide band. have.

For example, in (Patent Document 1), magnetic poles of adjacent strip magnets (or strip regions in a flat plate magnet plate) are alternately arranged differently, and the entire magnet plate made up of these many strip magnets is formed in a flat plate shape. An electroacoustic transducer is disclosed. The magnetic pole direction (magnetization direction) of the belt-like magnet is arranged so as to be perpendicular to the flat plate surface, and a flat voice coil diaphragm is arranged to face the front surface of the flat magnet plate.
Here, in a magnetic field formed by a magnet plate having a flat plate shape as a whole, a component parallel to the front surface of the magnet plate is defined as a parallel magnetic field component, and a component perpendicular thereto is defined as a vertical magnetic field component.

In the electroacoustic transducer of (Patent Document 1), since the magnetic pole directions are alternately changed, there are many portions where the direction of the magnetic field is reversed and portions where the magnetic field strength is low on the voice coil diaphragm. . Therefore, the magnetic field component that can be effectively used for sound generation, that is, the magnetic field component that contributes to sound generation in the magnetic field that generates electromagnetic force on the conductor of the voice coil diaphragm (hereinafter referred to as “effective magnetic field component”). The magnetic field strength (hereinafter referred to as “effective magnetic field strength”) also changed greatly.
Furthermore, in the electroacoustic transducer of (Patent Document 1), since the planar voice coil diaphragm is arranged in parallel to the flat magnet plate, the effective magnetic field component is only the parallel magnetic field component of the magnetic field. . Therefore, when the direction of the magnetic pole of the belt-shaped magnet is all perpendicular to the planar voice coil diaphragm, the parallel magnetic field component is reduced in the portion close to the magnetic pole, the effective magnetic field strength is reduced, and sound is generated. It becomes an area that cannot be used effectively.
In addition, in the electroacoustic transducer of (Patent Document 1), the winding direction of the conductor is reversed according to the direction of the magnetic field to be reversed, or the conductor is adjusted according to a region where the effective magnetic field strength exists partially. It was necessary to arrange. For this reason, the entire surface of the diaphragm cannot be used as a conductor, and a support member such as a synthetic resin sheet that closes the gap between the conductors is indispensable, and the vibration unique to the support member has an adverse effect on sound quality. Furthermore, there is a problem that the driving force of each part of the voice coil diaphragm varies greatly, which causes a divided vibration which is a big problem for reproducing high-quality sound.

Next, (Patent Document 2) discloses an electroacoustic transducer in which two types of magnet parts, a cylindrical shape and a ring shape, are concentrically separated on the center side and the outer peripheral side, respectively. A planar voice coil diaphragm in which a conductive material is spirally formed on an insulating film is used, and is disposed between the two types of magnet parts in parallel with the magnet parts. Each of the two types of magnet parts is composed of two magnets, and the total of the four magnets has a magnetization direction perpendicular to the voice coil diaphragm. The two magnets constituting the two kinds of magnet parts are combined so that the magnetic poles face each other, and the two kinds of magnet parts are installed so that the polarities are reversed between the center side and the outer peripheral part.
In this electroacoustic transducer, since the conductors are all wound in the same direction in a spiral shape, the entire surface of the voice coil diaphragm can be used as the conductor. Thereby, it becomes possible to generate a driving force on the entire surface of the voice coil diaphragm, which is effective for a problem such as (Patent Document 1).
However, even in this electroacoustic transducer, the magnetization direction of the magnet is only perpendicular to the voice coil diaphragm. For this reason, the distribution of the magnetic field formed by each of the two magnets constituting the two types of magnet parts, that is, the four magnets, has a small parallel magnetic field component near the magnetic pole and a low effective magnetic field strength. This is an area that cannot be used for vibration of the voice coil diaphragm. Therefore, the voice coil diaphragm is installed at a position away from the magnetic pole, and it is difficult to obtain a high effective magnetic field strength.
In addition, since the voice coil diaphragm is installed between the two types of magnet parts on the center side and the outer peripheral side, increasing the area of the voice coil diaphragm increases the spacing between the magnet parts and increases the effective magnetic field strength. descend. Therefore, a high effective magnetic field strength cannot be obtained while securing a sufficient area of the conductor portion.

As described above, the magnet plate of (Patent Document 1) or (Patent Document 2) in which the magnetization direction is only perpendicular to the voice coil diaphragm cannot increase the effective magnetic field component of the magnetic field formed by the magnet plate. Since the use efficiency of the magnet is poor and the region where the effective magnetic field strength is high is narrowed, there is a problem that a sufficient area cannot be secured while the entire surface of the voice coil diaphragm is used as a conductor.
Furthermore, since the effective magnetic field strength cannot be increased so much, the conversion efficiency to sound energy (hereinafter referred to as “efficiency”) cannot be increased.
Note that there are a ribbon type and a leaf type such as (Patent Document 5) as a structure that employs a diaphragm corresponding to a voice coil diaphragm in which a driving force generating portion is integrated with the diaphragm. These structures also cannot be widened because the area with high effective magnetic field strength cannot be widened, so the area of the voice coil diaphragm cannot be increased, and it is difficult to adopt it not only for the low-frequency range but also for the mid-range range. .
In order to solve these conventional problems, the present applicant diligently researched and patented (Patent Document 3), the magnetic plate is divided into many partial areas, and each partial area has a large effective magnetic field component. An electroacoustic transducer with a magnetization direction is disclosed. The voice coil diaphragm is formed by spirally winding a conductor into a flat shape, and is disposed in front of the magnet plate in parallel.
Since this electroacoustic transducer can widen a region having a high effective magnetic field strength, it can be employed as a structure for a low-frequency speaker in which the voice coil diaphragm is large. Further, since the effective magnetic field strength can be increased as compared with the cases of (Patent Document 1) and (Patent Document 2), the efficiency can be increased and the utilization efficiency of the magnet can be increased.
Furthermore, as in (Patent Document 3), a region having a high effective magnetic field strength can be widened, and although a high efficiency can be achieved, no special shape or processing is required as a magnet, and the process of finely setting the magnetization direction is omitted. An electroacoustic transducer (Patent Document 4) with improved performance is also disclosed.

Japanese Examined Patent Publication No. 35-10420 Japanese Utility Model Publication No. 60-93397 Japanese Patent No. 3612319 Japanese Patent No. 4810576 Japanese Patent Laid-Open No. 2003-70093

In the electroacoustic transducers of (Patent Document 3) and (Patent Document 4), by combining partial magnets, it is possible to secure a very wide region with a high effective magnetic field strength, and to adjust and equalize the effective magnetic field strength. You can also do it.
As a result, the entire surface of the voice coil diaphragm with a large area can be used as a conductor, and sound reproduction with extremely excellent transient characteristics can be performed up to the low frequency range. Moreover, the effective magnetic field intensity was increased and the efficiency could be increased.
These features make it possible to employ a voice coil diaphragm capable of driving the entire vibration surface in the same phase in the entire band from the low sound range to the high sound range. In speakers, headphones, etc., it was possible to realize an ideal full-plane planar speaker with low distortion, and to convert electrical signals into sound maintaining high quality. Microphones and the like have an excellent effect of being able to convert sound into electrical signals that maintain high quality.

(1) However, in the case of the structure adopted in the electroacoustic transducers of (Patent Documents 1 to 4), it is necessary to form a magnetic field in a wider space than the magnetic circuit of a general speaker such as a cone type, Since the magnetic field in the space by the magnet plate is developed three-dimensionally from the magnetic pole, the presence of a vertical magnetic field component is inevitable. The magnetic field in the space is divided into a parallel magnetic field component and a vertical magnetic field component, but only a parallel magnetic field component can be used with a planar voice coil diaphragm.
Therefore, most of the parallel magnetic field component contributes as an effective magnetic field component in the conductor region of the voice coil diaphragm and is used for driving the conductor (vibration of the voice coil diaphragm). The magnetic field component has not yet been used to drive the conductor.
Furthermore, even if the magnetic field strength is high, the region where the ratio of the vertical magnetic field component is large cannot be installed because the ratio of the parallel magnetic field component is small and the effective magnetic field strength is low. As described above, although the magnetic field strength is high, the ratio of the vertical magnetic field component is large, so that there are still many regions that are not used for the vibration of the voice coil diaphragm. In particular, in the disk-shaped magnet plate employed in (Patent Document 3) and (Patent Document 4), the ratio of the vertical magnetic field component is large even though the magnetic field strength at the center is very high. The magnetic field could not be used effectively.
(2) In general, when the frequency of sound generated by vibration of the diaphragm increases, the sound pressure decreases as the angle with respect to the vibration direction increases even if the distance from the diaphragm is the same. Deterioration of characteristics occurs.
In the case of an electroacoustic transducer using a conventional voice coil diaphragm such as (Patent Documents 1 to 4), the vibration direction of the voice coil diaphragm is only the central axis direction of the electroacoustic transducer. In the directivity characteristic, the sound pressure decreases as the angle with respect to the central axis, which is also the vibration direction, increases. Therefore, if the vibration direction itself is distributed outside the central axis, an effect of preventing a decrease in sound pressure can be expected in directions other than the central axis.
Since the vibration of the conductor driven by the vertical magnetic field component is parallel to the plane of the magnet plate, if the voice coil diaphragm can use not only the parallel magnetic field component but also the vertical magnetic field component, the voice coil diaphragm Can be vibrated in many directions, and the directivity may be greatly improved.
(3) Although the coaxial speaker is an ideal multi-way speaker, the high-frequency speaker is coaxial with the center of the low-frequency speaker as described in the third embodiment of (Patent Document 4). In such a case, it was necessary to incorporate a dedicated magnetic circuit for the loudspeaker. For this reason, new magnets are required for the magnetic circuit of the loudspeaker speaker, and the number of complicated processes for assembling parts for incorporating these magnets has increased. In particular, the loudspeaker parts are small, and when a new dedicated magnetic circuit is provided in the center, the structure becomes complicated and it is difficult to incorporate.
In the disk-shaped magnet plate employed in (Patent Document 3) and (Patent Document 4), the magnetic field strength at the center portion that is not used is considerably higher than the effective magnetic field strength in the voice coil diaphragm. However, since the magnetic field at the center has a large percentage of the vertical magnetic field component and a low effective magnetic field strength, it cannot be used to drive the conductor. Therefore, if the vertical magnetic field component can be used for driving the conductor, the high-frequency voice coil diaphragm can be installed without newly providing a magnet for the high-frequency speaker. Thus, it was considered that the use of the vertical magnetic field component was an effective means for allowing the high-frequency range speaker to be easily coaxially incorporated.
(4) When the high sound range speaker is arranged coaxially in the center of the low sound region speaker as described in the third embodiment of Patent Document 4, the magnet plate of the high sound region speaker is low. Entering the range of the speaker for the sound range affected the inner diameter side size of the voice coil diaphragm for the low frequency range. If the loudspeaker has a large caliber, the area that is not used for driving the central part is large, so there was no problem even if the loudspeaker was installed coaxially. The area that is not used for driving is reduced, and its influence is increased. The small-diameter coaxial two-way speaker unit has been strongly demanded because a high-performance speaker system that can be adapted to various usage forms can be constructed at a relatively low cost. However, for the reasons described above, it has been difficult to adopt a structure in which a loudspeaker is arranged coaxially with a small-diameter speaker.
Therefore, if the vertical magnetic field component can be used to drive the conductor, it will be possible to install only with the voice coil diaphragm for the high frequency range without newly providing a magnet for the high frequency range speaker. However, it will be possible to adopt a structure in which the loudspeakers are arranged coaxially.
From the above viewpoints, in addition to improving versatility and magnet utilization efficiency, the vertical magnetic field component is used in order to design better speakers than ever before, in terms of performance in terms of directivity and application to coaxial speakers. There has been a strong demand for the development of electroacoustic transducers used to drive electrical conductors.

The present invention responds to the above-mentioned demands, and in the electroacoustic transducer adopting the voice coil diaphragm, by utilizing not only the parallel magnetic field component of the magnetic field formed by the magnet plate but also the vertical magnetic field component, a new vibration form is obtained. This is intended to achieve further performance and diversification of electroacoustic transducers.
By using the vertical magnetic field component to drive the conductor, a speaker with excellent magnet utilization efficiency and excellent directivity characteristics is realized, and this high-frequency speaker is ideal for a multi-way speaker. The loudspeaker is installed without providing a dedicated magnetic circuit, thereby realizing a reduction in the overall size and adapting it to various usage forms.
The present invention is a speaker, headphone, earphone, or the like that can efficiently convert an electrical signal into sound that is excellent in sound quality, versatility, mass productivity, and resource saving in addition to the improvement of the above demand, or an electrical signal from sound An object of the present invention is to provide an electroacoustic transducer such as a microphone and a sound wave sensor that can efficiently perform conversion into a sound wave.

In order to solve the above problems, the electroacoustic transducer of the present invention has the following configuration.
The electroacoustic transducer according to claim 1 of the present invention includes a magnet plate and a coil vibrating body formed by winding a conductor and disposed in front of the magnet plate. The coil vibrating body is vibrated to generate sound by an electromagnetic force generated by a magnetic field formed by a magnet plate and an acoustic signal current flowing through the conductor of the coil vibrating body, or (b) the magnet plate An electroacoustic transducer that generates an acoustic signal current in the conductor of the coil vibrating body by the magnetic field formed by the vibration of the coil vibrating body due to sound, wherein the coil vibrating body includes the magnet plate A vibration surface that is inclined with respect to the front surface of the magnet plate, or a vibration surface that is perpendicular to the front surface of the magnet plate, the vibration surface is formed in a loop shape, and vibration of the coil vibrating body is at least of the magnet plate. A structure having a component parallel to the front surface It is equipped with a.
This configuration has the following effects.
(1) The coil vibration body has a vibration surface inclined with respect to the front surface of the magnet plate or a vibration surface perpendicular to the front surface of the magnet plate, and the vibration surface is formed in a loop shape. When the vibration surface vibrates so as to expand and contract in a direction nearly perpendicular to the vibration surface, the vibration of the coil vibrating body has a component parallel to the front surface of the magnet plate. As a result, the magnetic field formed by the magnet plate converts not only a parallel magnetic field component parallel to the front surface of the magnet plate but also a vertical magnetic field component perpendicular to the front surface of the magnet plate from an electric signal to sound, or from a sound to an electric signal. It can be used effectively for conversion to. In this way, the utilization efficiency of the magnet can be improved, and various structures can be adopted by a new vibration form having many possibilities.
(2) Since the composite of the parallel magnetic field component and the vertical magnetic field component of the magnetic field formed by the magnet plate can be used as the effective magnetic field component, the vibration of the coil vibrating body is only perpendicular to the surface of the magnet plate. In addition, it can be a vibration having a parallel component. If the vibration of the coil vibrating body can be a vibration having a component in a direction parallel to the surface of the magnet plate, the coil vibrating body can be vibrated in many directions. Therefore, the sound pressure in a direction deviating from the central axis direction of the electroacoustic transducer compared to the electroacoustic transducer using a cone type speaker or a conventional voice coil diaphragm where the vibration direction of the diaphragm is only the central axis direction. It is possible to greatly improve the directivity by reducing the decrease.
(3) Since the central part of the magnet plate employed in (Patent Document 3) and (Patent Document 4) has a large vertical magnetic field component, the coil vibrating body of the present invention is coaxially arranged in the central part and used for the high sound range. By using it as a speaker, a very high effective magnetic field strength can be obtained. In addition, this method can operate the coil vibrating body without providing a dedicated magnetic circuit for the loudspeaker, thus saving space and reducing the size of the coaxial speaker. . In this way, by adopting the coil vibrating body of the present invention for a high-frequency speaker of a coaxial speaker, the structure can be simplified, and it is extremely effective in reducing the number of parts and man-hours and improving performance such as directivity. A great effect can be obtained.
(4) Since the composite of the parallel magnetic field component and the vertical magnetic field component of the magnetic field formed by the magnet plate can be used as the effective magnetic field component, the effective magnetic field strength of the region used so far only increases. In addition, even in a region that has not been used so far, the effective magnetic field strength becomes high and a newly usable region is generated. Further, by adjusting the shape of the coil vibrating body in accordance with the magnetic field distribution, the tilt of the vibration surface of the coil vibrating body can be adjusted so that the effective magnetic field strength is increased, so that the restriction on the magnetic field distribution is reduced. As a result, the degree of freedom in designing the magnetic plate is increased, so that the design range can be expanded and the structure of the magnetic plate can be simplified, and the design flexibility and mass productivity are excellent.

Here, the coil vibrating body is formed by winding a conductor made of aluminum, copper, copper-clad aluminum wire, silver, gold or the like so as to have a predetermined shape in a thin plate shape, or by bending after winding. This is the shape. For bonding between conductors, silicone resin, epoxy, cyanoacrylate-based synthetic resin adhesives, etc. can be used, but soldering, wire bonding, etc. should be used for parts that do not require insulation. Can do.
When a linear conductor is wound and used, a plurality of wires are wound in parallel and adjusted to have a predetermined impedance. An insulated conductor may be used, but when a non-insulated conductor is used, the conductor groups in parallel are insulated and wound.
In addition, a conductor such as aluminum, copper, silver, gold, etc. on the surface of a thin substrate made of synthetic resin such as polyimide, polyethylene, polycarbonate, etc., which is a non-magnetic material, ceramic, synthetic fiber, wood fiber, or a composite material thereof. Can be used such that the pattern is formed into a predetermined shape by etching means, vapor deposition means, plating means, or the like, or the conductor portion is formed and then bent into a predetermined shape.
Further, as a method of forming a conductor pattern, there is a method of cutting a thin conductive plate such as copper or aluminum using means such as press working with a mold or laser processing.
In addition, as described in various conventional patent documents, the above-described means and processing methods may be more suitable for the purpose by using a plurality of them in combination rather than using them individually. Many.

The coil vibrating body has a vibrating surface inclined with respect to the front surface of the magnet plate or a vertical vibrating surface, and the vibrating surface is formed in a loop shape.
The point that the vibration of the coil vibrating body has a vibration component parallel to the front surface of the magnet plate is greatly different from the conventional one. In other words, it is not a flat shape like the conventional voice coil diaphragm, but a loop with a slanted surface or a vertical surface is formed and is a three-dimensional shape, so it is in a direction parallel to the front surface of the magnet plate. Can also vibrate.
In particular, a concave portion (valley fold portion) or a convex portion (mountain fold portion) is arranged in the circumferential direction of the vibration surface, and the top surface is curved so that the vibration surface is a concave portion (valley fold portion) or a convex portion (mountain fold portion). ) To support each other elastically and easily vibrate inward and outward (radial direction) of the loop, so that it has at least two concave portions (valley fold portions) or convex portions (mountain fold portions). It is preferable. As a result, the cross section of the coil vibrating body can be formed in various shapes. However, in the case of a circular shape, the magnetic field acts axisymmetrically and does not expand or contract in the radial direction, which is not preferable.
Even if it is circular, if it is formed in a loop shape while providing small irregularities on the vibration surface, it can be expanded and contracted in the radial direction by elastic deformation of the irregularities, so that sound is likely to be generated.
In this state, the electromagnetic force generated by the vertical magnetic field component and the acoustic signal current works to cause the vibration surface of the coil vibrating body to vibrate inward or outward of the loop. It can contribute to the effective magnetic field component.
The shape of the coil vibrating body may be increased or decreased toward the front of the magnet plate, and functions effectively even if the vibration surface is perpendicular to the front surface of the magnet plate. When installing a coil vibrating body with an enlarged or reduced diameter, the side facing the front side of the magnet plate is the back side because it is difficult for sound to be emitted to the outside, and the opposite side is used as the front side Is good. Therefore, when the diameter of the coil vibrating body is increased toward the front of the magnet plate, sound is emitted from the surface of the coil vibrating body toward the inside of the loop, and when the diameter is reduced, the surface of the coil vibrating body is Sound is emitted from the outside of the loop.

An electromagnetic force proportional to the parallel magnetic field component is generated in the direction perpendicular to the front surface of the magnet plate, and the electromagnetic force proportional to the vertical magnetic field component is generated in the direction parallel to the front surface of the magnet plate. Force is generated. Although the coil vibrating body vibrates due to this electromagnetic force, the vibration direction is influenced by the surrounding vibration and the support portion, and therefore does not necessarily coincide with the direction of the generated electromagnetic force.
The vibration generated in the coil vibrating body can be effectively used for converting a vibration component perpendicular to the vibration surface from an electric signal to sound. Therefore, in the coil vibrating body having a vibration surface perpendicular to the front surface of the magnet plate, only the vibration component parallel to the front surface of the magnet plate can be used effectively for conversion from an electric signal to sound.
The coil vibrating body is installed so that the effective magnetic field strength is higher than that of the conductor forming the vibration surface, so that the efficiency of the conversion from the electric signal to the sound or the conversion from the sound to the electric signal is high. Moreover, the utilization efficiency of a magnet can be improved.
For this purpose, it is preferable to install the vibration surface formed of a conductor so as to have a position and an angle at which the effective magnetic field strength is increased. That is, the coil vibrating body is installed at a position where the magnetic field strength is high, the vibrating surface formed of the conductor is parallel to the direction of the magnetic field, and the acoustic signal current flowing through the conductor is perpendicular to the direction of the magnetic field. Ideally, the direction should be transverse. In that case, the direction of the electromagnetic force is perpendicular to the vibration surface of the coil vibrating body.
Further, the efficiency can be increased by increasing the total area of the vibration surface of the coil vibrating body.

A second aspect of the present invention is the electroacoustic transducer according to the first aspect, wherein the vibration surface of the coil vibrating body is formed in a loop shape while repeating unevenness.
With this configuration, the following actions and effects are provided in addition to the actions and effects of the first aspect.
(1) The vibration surface of the coil vibrating body is formed in a loop shape with repeating irregularities so that the vibration surfaces elastically support each other and expand and contract in and out of the loop (in the radial direction). It becomes easy to vibrate. Therefore, the influence of the vibrations at the respective positions of the coil vibrating body is reduced, and uniform and stable vibration can be obtained. As a result, irregular vibrations are less likely to occur, and the frequency characteristics are easily uniformed.
(2) The efficiency can be increased as the total area of the conductor portion of the coil vibrating body is increased, but in general, when the outer diameter of the diaphragm is increased, the directivity characteristics are deteriorated in reproduction in a high sound range. However, in the present invention, the vibration surface of the coil vibrating body is formed in a loop shape with repeating irregularities, thereby increasing the total area of the vibration surface of the coil vibrating body with the same outer diameter as that of a conventional planar voice coil diaphragm. it can. Therefore, even if the area of the coil vibrating body is increased in order to increase efficiency, the outer diameter is not increased, and deterioration of directivity can be prevented.
(3) Further, since the outer diameter can be reduced while maintaining the total area of the vibration surface equivalent to that of the conventional planar voice coil diaphragm, the outer diameter is reduced while maintaining efficiency, and the directivity characteristics are reduced. Improvements can be made. In addition, by reducing the outer diameter and making it compact, it is possible to save space, and it is easy to install. Especially, it is easy to handle as a high-frequency speaker placed coaxially in the center of the low-frequency speaker. High sound quality and high performance can be realized.

Here, the vibration surface of the coil vibrating body is formed in a loop shape with repeating irregularities, and the shape thereof is such that each position of the coil vibrating body can vibrate in accordance with electromagnetic force, and the coil vibration of the present invention. As an electro-acoustic transducer using a body, it is determined taking into account the efficiency of conversion to sound energy (efficiency).
In order to allow each position of the coil vibrating body to vibrate according to the electromagnetic force, the coil vibrating body is easily deformed when vibrating. Further, since the coil vibrating body is elastically supported, vibrations generated at each position of the vibrating body are prevented from affecting each other. For that purpose, it is necessary to provide unevenness on the vibration surface and distribute it uniformly.
Next, in order to increase the efficiency, the coil vibrating body should be shaped so that sound can be generated efficiently as described below, and further, the generated sound can be shaped to be efficiently emitted to the outside. is important.

First, the shape of the coil vibrating body that can generate sound efficiently will be described.
Sound can be generated efficiently by making the vibration surface formed of a conductor incline so that the effective magnetic field strength is the highest. In general, the inclination with the highest effective magnetic field strength is that the vibration surface of the coil vibrating body formed of a conductor is parallel to the direction of the magnetic field, and the acoustic signal current flowing through the conductor is in the direction of the magnetic field. The inclination is perpendicular to the direction.
The coil vibration body has a plurality of bent portions, and the shape of the entire coil vibration body is often complicated, and the gradient of the effective magnetic field strength is the highest for all vibration surfaces formed of the conductor. It is difficult. Therefore, it is preferable that the direction of the vibration surface is an angle that generally increases the effective magnetic field strength.
In general, in order to achieve the highest efficiency with respect to the central axis direction, that is, the direction perpendicular to the front surface of the magnet plate at the center of the magnet plate, the inclination angle of the vibration surface with respect to the front surface of the magnet plate is It is about 70 to 20 degrees, preferably about 60 to 30 degrees.
The direction of the magnetic field in such a range makes it easy to obtain a high magnetic field strength, and since it is set to a certain range, the change in the vibration direction is reduced and stable vibration is easily obtained.
As the tilt angle of the vibration surface with respect to the front surface of the magnet plate becomes larger than 60 degrees, the parallel component of the vibration of the coil vibrating body tends to increase, making it difficult to contribute to the efficiency with respect to the central axis direction at a high frequency. . Further, as the inclination angle of the vibration surface with respect to the front surface of the magnet plate becomes smaller than 30 degrees, it tends to be difficult to obtain high magnetic field strength. Furthermore, when the inclination angle of the vibration surface with respect to the front surface of the magnet plate is larger than 70 degrees or smaller than 20 degrees, these tendencies become remarkable, which is not preferable.
Note that a magnetic field distribution suitable for a vibration surface having a large tilt angle can be obtained relatively easily, and the magnetic field strength tends to increase. Therefore, it is effective to adopt a vibrating surface with an angle with respect to the front surface of the magnet plate of 70 degrees or more by means such as using with a diffuser.

Next, the shape in which the generated sound is efficiently emitted to the outside will be described.
In order to efficiently emit the generated sound to the outside, it is necessary to prevent the recesses from becoming deeper in the uneven portions.
Further, when the diameter of the coil vibrating body is increased toward the front of the magnet plate, sound is radiated from the surface of the coil vibrating body toward the inside of the loop, but deeper as the height of the coil vibrating body increases. Since the sound at the position becomes difficult to be released to the outside, it is generally preferable that the height of the coil vibrating body is low. Furthermore, sound is more likely to be emitted to the outside when the inclination angle of the vibration surface is smaller.
When the diameter of the coil vibrating body is increased toward the front of the magnet plate, the coil vibrating body itself becomes close to the shape of the horn, and thus the characteristics of the horn type speaker are also shown. When the characteristics of the horn type speaker are positively used, the horn design condition is obeyed. In that case, the height of the coil vibrating body may be increased.
Since there are conflicting conditions as described above, the shape of the coil vibrating body is comprehensively determined according to the purpose based on these conditions.

By configuring the magnet plate with the means proposed in (Patent Document 3) and (Patent Document 4) as the magnet plate under the above conditions, a high effective magnetic field strength can be obtained even in the present invention. That is, it is most preferable to use a magnet plate in which the entire magnet plate is divided into a plurality of partial areas, and each partial area has a magnetization direction for increasing the use efficiency of the magnet.
A magnetic plate in which a columnar magnet with a magnetization direction perpendicular to a central hole of a cylindrical magnet with a magnetization direction as a radial direction is relatively easily obtained with a high effective magnetic field strength.
In general, in the case of a cylindrical magnet, the direction of the magnetic field with respect to one end face of the magnetic pole is almost in the range of about 90 to 30 degrees at the portion where the magnetic field strength is high. Therefore, even if the coil vibrating body of the present invention is simply set in front of one of the magnetic poles of the cylindrical magnet, the efficiency can be reduced, but it can be easily used as an electroacoustic transducer.
As described above, the coil vibrating body of the present invention also has versatility that it can be easily adapted to various magnet plates.

A third aspect of the present invention is the electroacoustic transducer according to the first or second aspect, wherein the electroacoustic transducer includes a plurality of the coil vibrating bodies.
With this configuration, the following actions and effects are provided in addition to the actions and effects of the first or second aspect.
(1) When a plurality of bending portions are provided, the overall shape of the coil vibrating body becomes complicated and difficult to manufacture. However, the coil vibrating body can be easily realized by dividing it into a plurality of coil vibrating bodies. Become.
(2) Since a complicated shape can be easily realized when divided into a plurality of coil vibrating bodies, it becomes easy to adjust the inclination of the vibration surface formed of the conductor. Therefore, the adjustment of the tilt of the vibration surface for increasing the effective magnetic field strength is facilitated.
(3) Since the coil vibrating body is divided into a plurality of parts, the loop of the coil vibrating body is unlikely to be higher than the front direction of the magnet plate. Therefore, the conductor of the coil vibrating body is distributed at a position close to the magnet plate, that is, at a position where the magnetic field strength is high, and the use efficiency of the magnet is increased. Further, even when the diameter of the coil vibrating body is increased toward the front of the magnet plate, sound is easily emitted to the outside.
(4) A coil vibrating body whose diameter is expanded toward the front of the magnet plate or a coil vibrating body whose diameter is reduced can be combined. The characteristics and directivity can be finely adjusted.

According to the electroacoustic transducer of the present invention, the following advantageous effects can be obtained.
According to invention of Claim 1, it has the following effects.
(1) A vibrating surface inclined with respect to the front surface of the magnet plate of the coil vibrating body or a vibrating surface perpendicular to the front surface of the magnet plate vibrates so as to expand and contract in a direction nearly perpendicular to the vibrating surface. The vibration of the coil vibrating body has a component parallel to the front surface of the magnet plate. If the vibration of the coil vibrating body also has a component in a direction parallel to the surface of the magnet plate, the coil vibrating body can be vibrated in many directions. Thereby, the utilization efficiency of a magnet can be improved and it comes to be excellent in design flexibility. Moreover, since the sound pressure drop in the direction deviating from the central axis direction can be reduced, an excellent electroacoustic transducer having extremely good directivity can be provided.

According to invention of Claim 2, in addition to the effect of Claim 1, it has the following effects.
(1) The vibration surfaces of the coil vibrating body elastically support each other and easily vibrate so as to expand and contract in and out of the loop (in the radial direction). Therefore, the influence of the vibrations at the respective positions of the coil vibrating body is reduced, and uniform and stable vibration can be obtained. In this way, it is possible to provide an electroacoustic transducer having uniform frequency characteristics in which irregular vibration hardly occurs.

According to invention of Claim 3, in addition to the effect of Claim 1 or 2, it has the following effects.
(1) An electroacoustic transducer that can easily realize the shape of a coil vibration body having a complicated shape can be provided by dividing the coil vibration body into a plurality of coil vibration bodies and combining them.

Sectional schematic end view of the main part of the electroacoustic transducer in the first embodiment Main part schematic plan view of electroacoustic transducer in Embodiment 1 1 is a schematic perspective view of a main part showing an outer shape of a coil vibrating body of an electroacoustic transducer according to Embodiment 1. Sectional schematic end view of the main part of the electroacoustic transducer in the second embodiment The principal part schematic plan view of the electroacoustic transducer in Embodiment 2 Sectional schematic end view of the main part of the height direction intermediate portion of the coil vibrating body of the electroacoustic transducer in the third embodiment Sectional schematic end view of the main part of the middle portion in the height direction of the coil vibrating body showing the first modification of the electroacoustic transducer in the third embodiment Sectional schematic end view of a main part of the intermediate portion in the height direction of the coil vibrating body showing a second modification of the electroacoustic transducer in the third embodiment Sectional schematic end view of the main part of the middle portion in the height direction of the coil vibrating body showing a third modification of the electroacoustic transducer in the third embodiment Sectional schematic end view of the main part of the intermediate portion in the height direction of the coil vibrating body showing the fourth modification of the electroacoustic transducer in the third embodiment

Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited to these embodiments.
(Embodiment 1)
The electroacoustic transducer in Embodiment 1 is demonstrated.
1 is a cross-sectional schematic end view of the main part of the electroacoustic transducer in the first embodiment, FIG. 2 is a schematic plan view of the main part of the electroacoustic transducer in the first embodiment, and FIG. It is a principal part model perspective view which shows the external shape of the coil vibration body of the electroacoustic transducer in.
1 and 2, reference numeral 10 denotes an electroacoustic transducer according to the first embodiment in which a coil vibrating body 30 is disposed in front of a magnet plate 20 described later.
First, the magnet plate used for the electroacoustic transducer of Embodiment 1 will be described.
In FIG. 1, 20 is a magnet plate of the electroacoustic transducer 10 that is configured in a substantially disk shape, 21 is a central region magnet that uses a cylindrical neodymium magnet in a partial region on the center side of the

magnet plate

20, and 21 a A bolt insertion hole 22 provided in the center of the center area magnet 21 is a partial area around the magnet plate 20, and a plurality of trapezoidal small magnets 22 b using neodymium magnets are arranged radially around the center area magnet 21. It is a basic area magnet arranged and configured.
In FIG. 2, reference numeral 22 a denotes a plurality of sound passage holes formed between the trapezoidal small magnets 22 b adjacent to each other in the basic area magnet 22.

In FIG. 1, the cylindrical central region magnet 21 is magnetized in the axial direction of the magnet plate 20. The basic area magnet 22 is magnetized in the radial direction. In the present embodiment, the basic region magnet 22 is configured by combining a plurality of trapezoidal small magnets 22 b, but a single cylindrical magnet magnetized in the radial direction may be used as the basic region magnet 22. Although the sound passage hole is not necessarily provided, a gap is provided between the center region magnet 21 and the basic region magnet 22 instead of the sound passage hole 22a, and can be used as the sound passage hole.

Next, the detail of the coil vibrating body used for the electroacoustic transducer of Embodiment 1 is demonstrated.
In FIG. 1, 31 is a conductor that is wound in a spiral shape to form the

coil vibrating body

30, and 33 is a vibration surface of the coil vibrating body 30 that is inclined with respect to the front surface of the magnet plate 20. The inclination angle of the vibration surface 33 of the coil vibrating body 30 can be appropriately selected according to the direction of the magnetic field formed by the magnet plate 20 so that the effective magnetic field strength is comprehensively increased. By making the inclination angle of the vibration surface 33 with respect to the front surface 70 to 20 degrees, preferably 60 to 30 degrees, the efficiency can be increased by effectively using the magnetic field.
As shown in FIG. 3, by alternately providing the mountain folds 33x and the valley folds 33y in the circumferential direction of the coil vibrating body 30 and curving the top, the vibration surface 33 is formed in a loop shape with repeated irregularities. Yes.
In order to form the coil vibrating body 30 having the shape as shown in FIG. 3, first, a conductor 31 made of an insulated copper clad aluminum wire is wound in a spiral shape, and an adhesive is applied to the back surface and fixed. To create a planar coil. Various methods for producing a planar coil have been disclosed so far, but any method may be used as long as a planar coil can be formed.
Thereafter, the planar coil can be pressed against a mold or the like formed in the same shape as the coil vibrating body 30 shown in FIG.
This method of forming the coil vibrating body 30 once by forming a planar coil once is easy to manufacture, but the inclination angle of the vibration surface 33 is limited to some extent. In order to make the coil vibrating body 30 in an ideal shape, after determining a shape that has the highest effective magnetic field strength and that facilitates sound emission, the shape is obtained by means such as winding, vapor deposition, or plating. It is advisable to adopt a method that directly builds them together.

The structure of the electroacoustic transducer 10 using the magnet plate 20 and the coil vibrating body 30 configured as described above will be described.
In FIG. 1, reference numeral 40 denotes a non-magnetic cylindrical frame surrounding the outer periphery of the coil vibrating body 30, and reference numeral 40 a denotes a nonmagnetic disk-shaped opening 40 b that matches the shape of the outer periphery of the coil vibrating body 30. A front support frame that supports the outer peripheral side of the coil vibrating body 30 together with the

cylindrical frame

40, and 41 is a silicone resin made of a silicone resin that seals between the irregularities on the inner peripheral side of the coil vibrating body 30 and the central region magnet 21. An inner peripheral side support portion for elastically supporting the inner peripheral side of the

body

30, 42 is filled so as to seal between the irregularities on the outer peripheral side of the coil vibrating body 30 and the cylindrical frame 40 and the front support frame 40 a. An outer peripheral side support portion that elastically supports the outer peripheral side of the coil vibrating body 30 with silicone resin, 45 is filled in a space surrounded by the rear surface of the coil vibrating body 30, the inner peripheral surface of the cylindrical frame 40, and the magnet plate 20. glass A sound absorbing material using a tool or the like, 51 is an outer peripheral frame formed of a non-magnetic material in a cylindrical shape and installed on the outer peripheral side of the

basic region magnet

22, and 52 is a non-magnetic material formed in a ring shape to form the basic region magnet 22. An intermediate frame of the electroacoustic transducer 10 supported at the front, 53 is a non-magnetic ring-shaped central frame installed in front of the

central area magnet

21, and 53 a is a bolt insertion hole provided at the center of the central frame 53. , 54 is a non-magnetic body formed in a ring shape and supports the magnet plate 20 at the rear, the rear frame of the

electroacoustic transducer

10, 54a is a bolt insertion hole provided in the center of the

rear frame

54, and 54b is opened in the rear frame 54 A plurality of sound passage holes 56 formed so as to form a portion are non-magnetic through the central frame 53, the bolt insertion hole 21a of the central area magnet 21, and the bolt insertion hole 54a of the rear frame 54. Ltd. bolts 57 center frame 53 is screwed to the bolt 56 in the rear surface of the rear frame 54, the magnet plate 20, which is a non-magnetic material made of a nut fixedly connecting the rear frame 54.
The arrow represents the direction of the magnetic field formed by the magnet plate 20.

In FIG. 1, since the magnetic force pushed forward by the basic region magnet 22 acts on the center region magnet 21, there is a possibility that it will come off only with an adhesive when fixed to the rear frame 54. Therefore, the center region magnet 21 is fixed by being sandwiched between the center frame 53 and the rear frame 54 using the bolt 56 and the nut 57. In addition, since the magnetic force acts on the basic region magnet 22 in the direction in which it is pressed against the rear frame 54 by the central region magnet 21, it is difficult to come off just by bonding, but it is difficult to disassemble the combined small magnets 22b. A cylindrical outer peripheral frame 51 is provided.

In the electroacoustic transducer 10 of the present embodiment, the direction of the magnetic field formed by the magnet plate 20 is as shown by the arrow in FIG. 1, but when a current is passed through the conductor 31 of the coil vibrating body 30, the coil vibrating body 30. The electromagnetic force acts in a direction perpendicular to both the direction of the magnetic field and the direction of current flow. That is, an electromagnetic force works in a direction near the perpendicular to the vibration surface 33 of the coil vibrating body 30. As a result, the entire coil vibrating body 30 vibrates by operating alternately in the contracting direction and the expanding direction, and generates sound. Since the coil vibrating body 30 itself deforms and vibrates to generate sound, the inner circumferential side support portion 41 that supports the inner circumferential side of the coil vibrating body 30 and the outer circumferential side support that supports the outer circumferential side of the coil vibrating body 30. It is preferable to use an elastic material such as a silicone resin for the portion 42.
In addition, since the sound on the rear surface side of the coil vibrating body 30 interferes with the sound on the front surface side of the coil vibrating body 30, it is necessary to reduce leakage to the outside as much as possible. Therefore, in order to attenuate the sound on the rear surface side of the coil vibrating body 30, the sound absorbing material 45 is installed in the space surrounded by the rear surface of the coil vibrating body 30, the inner peripheral surface of the cylindrical frame 40, and the magnet plate 20.
The sound that has passed through the sound absorbing material 45 is allowed to reach the sound passage hole 22a (FIG. 2), and if more space behind the coil vibrating body 30 is required, the electric sound can be transmitted from the sound passage hole 54b (FIG. 1). It can be discharged to the outside of the converter 10. In that case, it is possible to select filling the sound passage hole 22a with a sound absorbing material or increasing the size of the sound passage hole 22a according to the situation. Further, a sound passage hole may be provided in the outer peripheral frame 51 and discharged to the outside of the electroacoustic transducer 10.
In addition, when the space behind the coil vibrating body 30 may be small, the space between the rear of the cylindrical frame 40 and the inner peripheral side support portion 41 is sealed so that the sound on the rear surface side of the coil vibrating body 30 is heard. You may interrupt | block in the step before reaching the sound passage hole 22a.

The use efficiency of the magnetic field formed by the magnet plate 20 increases as the vibration surface 33 of the coil vibration body 30 and the direction of the magnetic field are closer to parallel, and as the winding direction of the conductor 31 and the direction of the magnetic field are closer to perpendicular. .
Therefore, when the coil vibrating body 30 is formed, the vibrating surface 33 is close to parallel to the direction of the magnetic field in the widest possible area of the coil vibrating body 30, and the winding direction of the conductor 31 and the direction of the magnetic field. It is preferable to design the shape, number, arrangement, and the like of the mountain folds 33x and the valley folds 33y so that is close to vertical.
Lead wires (not shown) are drawn out from the inner circumference side and the outer circumference side of the conductor 31 wound in a spiral shape in the coil vibrating body 30 and connected to terminals (not shown). When the electroacoustic transducer 10 is used as a speaker, headphones, or the like, a drive current can be supplied from the outside from a terminal.
When the electroacoustic transducer 10 is used as a microphone or the like, the coil vibrating body 30 is vibrated by sound, and an electromotive force generated in the conductor 31 is taken out as an electrical signal from a terminal to which a lead wire is connected.

In the present embodiment, the magnet plate 20 is configured by combining two types of magnets, that is, the central region magnet 21 and the basic region magnet 22. However, the configuration of the magnet plate 20 is not limited to this, and is appropriately selected. be able to. For example, when the magnet plate is composed only of a cylindrical magnet magnetized in the axial direction, the output sound pressure level is reduced, but the amount of magnet used can be reduced, and the configuration of the magnet plate can be simplified to The acoustic transducer can be miniaturized.
Further, in the present embodiment, the case where the coil vibrating body 30 is used alone has been described. However, the high-frequency range speaker described in Embodiment 3 of (Patent Document 4) is replaced with the low-frequency range speaker. In the composite type speaker arranged coaxially in the center portion, the magnet portion for the high frequency range speaker provided exclusively is not required by adopting the coil vibrating body 30 as the high frequency range speaker. That is, a low-frequency speaker that is not coaxial is configured, and a high-performance coaxial composite speaker is configured simply by placing the coil vibrating body 30 surrounded by the cylindrical frame 40 in the center as a high-frequency speaker. it can. In that case, it may be better to change the size of the partial magnet at the center in order to increase the efficiency of the loudspeaker speaker, but it is not necessary to change the type or basic structure of the magnet.

According to the electroacoustic transducer in Embodiment 1 configured as described above, the following operation is obtained.
(1) The coil vibrating body has a vibrating surface inclined with respect to the front surface of the magnet plate, and the vibrating surface is formed in a loop shape so that the vibrating surface of the coil vibrating body is perpendicular to the front surface of the magnet plate. In addition to the direction (axial direction), it can vibrate so as to expand and contract in a direction parallel to the front surface of the magnet plate (radial direction = inward direction and outward direction of the loop). Therefore, the magnetic field formed by the magnet plate can effectively use not only a parallel magnetic field component parallel to the front surface of the magnet plate but also a vertical magnetic field component perpendicular to the front surface of the magnet plate. In this way, the effective magnetic field strength can be increased and the utilization efficiency of the magnet can be improved.
(2) Since the vertical magnetic field component perpendicular to the front surface of the magnet plate can be used, the vertical magnetic field component can generate a vibration component parallel to the front surface of the magnet plate in the vibration of the coil vibrating body. It was. Since this vibration component is in the direction parallel to the front surface of the magnet plate, the sound pressure drop in the direction away from the central axis direction of the speaker can be reduced and the directivity can be greatly improved. Higher performance can be realized. In addition, since the vibration surface of the coil vibrating body is formed in a loop shape with repeated irregularities, the outer diameter can be reduced with an area equivalent to that of a conventional flat voice coil diaphragm. The directivity is improved. As described above, according to the coil vibrating body of the present invention, it is possible to realize an excellent speaker with greatly improved directivity characteristics.
(3) When the coil vibrating body is employed as a high-frequency speaker for a coaxial composite speaker, a magnet section dedicated to the high-frequency speaker is not required. Since there is no need for a magnet space for high-frequency speakers, a coaxial composite speaker can be constructed even with a small-diameter speaker, and the structure of the magnet is simplified, making it very easy to manufacture. Become. A coaxial speaker is considered to be an ideal multiway speaker. In this way, a high-performance composite speaker that can be miniaturized and has excellent directivity can be constructed.
(4) Since a combination of the parallel magnetic field component and the vertical magnetic field component of the magnetic field formed by the magnet plate can be used as the effective magnetic field component, the effective magnetic field strength is low only with the conventional parallel magnetic field component, and the coil vibrator By combining with a vertical magnetic field component even in a region that could not be used for vibration, the effective magnetic field strength can be increased and the region that can be used for vibration of the coil vibrating body can be expanded. Furthermore, since the use range of the magnetic field distribution has expanded, the design range of the magnet plate can be expanded to simplify the structure of the magnet plate, and the design flexibility and mass productivity are excellent.
(5) Since the vibration surface of the coil vibrating body is formed in a loop shape with repeating irregularities, the vibration surfaces elastically support each other and expand and contract in and out of the loop (in the radial direction). It becomes easy to vibrate. As a result, the influence of each position's vibration on each other is reduced, and a uniform and stable vibration can be obtained, and an electroacoustic transducer having uniform frequency characteristics and less likely to generate irregular vibrations is provided. Will be able to.

(Embodiment 2)
The electroacoustic transducer in Embodiment 2 is demonstrated. In addition, the same code | symbol is attached | subjected to the thing similar to Embodiment 1, and description is abbreviate | omitted.
4 is a schematic cross-sectional end view of the main part of the electroacoustic transducer in the second embodiment, and FIG. 5 is a schematic plan view of the main part of the electroacoustic transducer in the second embodiment.
4 and 5, the electroacoustic transducer 10A according to the second embodiment is different from the first embodiment in that three coil vibrating bodies 30A to 30C are arranged concentrically in front of the magnet plate 20. And the outer peripheral side of the coil vibrating body 30C and the basic region magnet 22 is surrounded by a common cylindrical frame 40A.
4 and 5, reference numerals 33A to 33C denote vibration surfaces of the coil vibrating bodies 30A to 30C inclined with respect to the front surface of the magnet plate 20. The coil vibrating bodies 30A to 30C can be formed in the same manner as the coil vibrating body 30 of the first embodiment, except that the dimensions are different. However, the

coil vibration bodies

30B and 30C on the intermediate part and the outer peripheral side have the vibration surfaces 33B and 33C expanded in diameter toward the front of the magnet plate 20 as in the coil vibration body 30 of the first embodiment. The side (center side) coil vibrating body 30 A has a vibrating surface 33 A reduced in diameter toward the front of the magnet plate 20.
4 and 5, reference numeral 41A denotes an inner periphery formed of a silicone resin in a sheet shape and elastically supporting the inner peripheral side of the coil vibrating body 30A while sealing the uneven portion on the inner peripheral edge side of the coil vibrating body 30A. The side support portion 42A is formed of a silicone resin into a sheet shape, and the outer peripheral side elastically supports the outer peripheral side of the coil vibrating body 30C while sealing between the irregularities on the outer peripheral side of the coil vibrating body 30C and the cylindrical frame 40A. The support portion 43A is made of silicone resin, and seals the concavo-convex portions between the outer peripheral side of the coil vibrating body 30A and the inner peripheral side of the coil vibrating body 30B, and the outer peripheral side of the coil vibrating body 30A and the inner peripheral side of the coil vibrating body 30B. The intermediate support portion 44A joined to the center region magnet 21 of the magnet plate 20 is formed into a sheet shape with silicone resin, and the outer peripheral side of the coil vibrating body 30B and the coil vibrating body Intermediate support joined elastically to the outer peripheral side of the coil vibrating body 30B and the inner peripheral side of the coil vibrating body 30C and sealed to the basic region magnet 22 of the magnet plate 20 while sealing the uneven part between the inner peripheral side of 0C. Part.

In the electroacoustic transducer 10A of the present embodiment, the direction of the magnetic field formed by the magnet plate 20 is as shown by the arrow in FIG. 4, but when an electric current is passed through the conductors 31 of the coil vibrating bodies 30A to 30C, the coil vibrations Electromagnetic force acts on the bodies 30A to 30C in a direction perpendicular to both the direction of the magnetic field and the direction of current flow. In general, the use efficiency of the magnetic field is the highest when the electromagnetic force acts and vibrates in the direction perpendicular to the vibration surfaces 33A to 33C of the coil vibrating bodies 30A to 30C.
In the magnet plate used in the first or second embodiment, if the outer diameter of the magnet plate 20 is reduced or the magnet plate 20 is formed thin as in the present embodiment, the distance from the front surface of the magnet plate 20 is reduced. However, the decrease rate of the magnetic field strength tends to increase. Therefore, in the present embodiment, the coil vibrating body is divided into three types of coil vibrating bodies 30A to 30C so that the height of each of the coil vibrating bodies 30A to 30C does not become higher than the front direction of the magnet plate 20. Thus, the conductor 31 is disposed in a region having a high magnetic field strength.

The coil vibrating body vibrates by moving alternately in the direction of contraction and the direction of expansion, and generates sound, so that it functions effectively regardless of whether the shape is expanded or contracted.
When installing a coil vibrating body having an enlarged or reduced diameter, the side facing the front surface of the magnet plate 20 is used as the back surface because sound is hardly emitted to the outside, and the opposite surface is used as the surface. Therefore, in the case of the

coil vibrating bodies

30B and 30C whose diameter is increased toward the front of the magnet plate 20, sound is emitted from the surface of the

coil vibrating bodies

30B and 30C toward the inside of the loop, and the diameter is reduced. In the case of the coil vibrating body 30A, sound is radiated from the surface of the coil vibrating body toward the outside of the loop.

When the plurality of coil vibrating bodies 30A to 30C are arranged concentrically as in the present embodiment, the coil vibrating bodies 30A to 30C can generate sound regardless of which diameter is expanded or reduced. However, in the present embodiment, the use efficiency of the magnetic field is enhanced by making use of each feature.
In order to prevent the expanded coil vibrator from emitting sound toward the inside of the loop and making it difficult for the sound to be emitted to the outside, it is better to lower the height of the coil vibrator. The inclination angle of the coil vibrating body with respect to the magnet plate 20 should be reduced. In the present embodiment, the direction of the magnetic field formed by the magnet plate 20 is such that the tilt angle with respect to the front surface of the magnet plate 20 decreases as the distance from the center of the magnet plate 20 decreases. However, the use efficiency of the magnetic field becomes higher when the angle is reduced in accordance with the angle. Since the mutual conditions are met in this way, the

coil vibration bodies

30B and 30C on the intermediate portion and the outer peripheral side are used in a shape in which the diameter is increased.
Further, the inclination angle of the vibration surface 33C with respect to the front surface of the magnet plate 20 is smaller than the inclination angle of the vibration surface 33B of the coil vibration body 30B at the intermediate portion. This is done in order to increase the effective magnetic field intensity by bringing the inclination of the vibration surface closer to the direction of the magnetic field and to make it easier to emit sound to the outside.

The coil vibrating body with a reduced diameter emits sound from the surface of the coil vibrating body toward the outside of the loop, so there is no limitation as with the coil vibrating body with an enlarged diameter, but the inclination is such that the diameter is reduced. It is difficult to distribute the magnetic field of the magnet plate 20 so as to be parallel to the vibration surface in the direction. Accordingly, the reduced-diameter coil vibrating body is a coil vibrating body whose diameter is increased, such as a region where the angle with respect to the magnet plate 20 in the magnetic field direction is large or a region where the magnetic field strength is high up to a position away from the magnet plate 20. It is good to adopt it in an unsuitable area.
The coil vibrating body 30A on the inner peripheral side is used with a reduced diameter so that the distribution of the magnetic field in the installed area meets these conditions. As shown in FIG. This is because it is difficult to make the direction of the magnetic field of the magnet plate 20 coincide with the inclination direction of the vibration surface 33A of the coil vibrating body 30A.
Here, although the coil vibrating body 30A is used with a reduced diameter, the vibrating surface 33A is brought close to the direction of the magnetic field by making the vibrating surface 33A 90 degrees with respect to the front surface of the magnet plate 20, that is, perpendicular to the magnetic field. Can improve the efficiency of use. Further, as the angle of the magnetic field with respect to the front surface of the magnet plate 20 approaches 90 degrees, the vibration of the coil vibrating body increases in the parallel direction component with respect to the surface of the magnet plate 20, so Improvement can be expected.
However, the reduced-diameter coil vibrating body can also serve as a diffuser because the shape of the vibrating body itself becomes a shape that diffuses sound like the coil vibrating body 30A. Therefore, in this embodiment, the angle is set such that the sound generated by the coil vibrating body 30B is reflected and diffused by using this function.

When arranging a plurality of coil vibrating bodies as in the present embodiment, it is necessary to consider the phase of the sound generated by each coil vibrating body.
When the phases of the sounds generated by the

coil vibrating bodies

30A, 30B, and 30C according to the present embodiment are matched, acoustic signal currents are supplied in the same phase between the expanded coil vibrating body 30B and the coil vibrating body 30C. The acoustic signal current is supplied to the coil vibrating body 30A having a reduced diameter so as to have an opposite phase to the

coil vibrating bodies

30B and 30C having the increased diameter.
The joining between the conductors 31 is preferably performed on the back surface side of the coil vibrating body regardless of whether the coil vibrating bodies 30A to 30C have a reduced diameter or an enlarged diameter. This is because sound is directly emitted from the conductor 31 without going through an adhesive or the like, which is advantageous in terms of sound quality.

The electroacoustic transducer 10A of the second embodiment configured as described above can be used as a speaker, a headphone, etc., or a microphone, etc., like the electroacoustic transducer 10 of the first embodiment. The sound quality of the electroacoustic transducer using the voice coil diaphragm can be improved.
In the present embodiment, since the outer diameter of the basic region magnet 22 is reduced to reduce the size of the magnet plate 20, the rate of decrease in magnetic field strength tends to increase with respect to the distance from the front surface of the magnet plate 20. is there. Therefore, the plurality of coil vibrating bodies 30A to 30C are arranged concentrically with a narrow width, and are arranged in a region having a high magnetic field strength close to the magnet plate 20, thereby preventing the efficiency from being reduced even with a small size. 10A can be configured.

According to the electroacoustic transducer in the second embodiment configured as described above, the following operation is obtained in addition to the same operation as in the first embodiment.
(1) In order to arrange a plurality of coil vibrators having different sizes and characteristics concentrically (coaxially), a coil vibrator whose diameter is enlarged toward the front of the magnet plate and a coil vibrator whose diameter is reduced are combined. Can do. Therefore, the shape and inclination of the vibration surface can be finely adjusted for each coil vibrating body in accordance with the distribution state of the magnetic field, and the use efficiency of the magnetic field can be increased.
(2) Further, by combining the coil vibrating bodies with different characteristics from each other, a composite electroacoustic transducer having excellent acoustic characteristics as a whole can be obtained. For example, frequency characteristics, directivity characteristics, efficiency, etc. can be finely adjusted by properly using the size and shape of the diaphragm and the inclination of the vibration surface for each coil vibrator.
(3) Since the coil vibrating body is divided into a plurality of parts, the loop of the coil vibrating body is unlikely to be higher than the front direction of the magnet plate. Therefore, the conductor of the coil vibrating body is distributed at a position close to the magnet plate, that is, at a position where the magnetic field strength is high, and the use efficiency of the magnet is increased. Further, even when the diameter of the coil vibrating body is increased toward the front of the magnet plate, sound is easily emitted to the outside.

(Embodiment 3)
The electroacoustic transducer in Embodiment 3 is demonstrated. In addition, the same code | symbol is attached | subjected to the thing similar to Embodiment 1 or 2, and description is abbreviate | omitted.
FIG. 6 is a cross-sectional schematic end view of the main part of the intermediate portion in the height direction of the coil vibrating body of the electroacoustic transducer in the third embodiment.
In FIG. 6, the electroacoustic transducer 10B according to the third embodiment is different from the first embodiment in that the conductor 31 is wound so that the coil vibrating body 30D has an elliptical shape.
An acoustic signal current flows through the conductor 31 wound in an elliptical shape, and electromagnetic force is generated alternately in the inner direction and the outer direction, whereby the oblateness of the ellipse changes alternately in magnitude and generates sound.
The shape of the coil vibrating body 30 D may be increased or decreased toward the front of the magnet plate as in the first or second embodiment, and effectively functions as a cylindrical shape. When the diameter is reduced, the valley fold 33y in FIG. 6 becomes the mountain fold 33x.
Since the structure of the coil vibrating body 30D is not complicated, the electroacoustic transducer 10B is easy to design and manufacture and has excellent versatility.
When a coil vibrating body having an enlarged diameter or a reduced diameter is installed, the surface on the magnet plate side is used as the back surface because sound is hardly emitted to the outside, and the surface on the opposite side is used as the surface. In any case, the greater the inclination angle of the magnetic field with respect to the front surface of the magnet plate, the greater the component in the direction parallel to the surface of the magnet plate. When the parallel component increases, good directivity can be obtained. However, since the vibration of the vertical component decreases and the efficiency in the central axis direction decreases, it is preferable to use these features depending on the use situation.
Note that the coil vibrating body 30D having an elliptical shape is easily expanded and contracted in the inner and outer directions of the loop by elastic deformation by forming a loop shape while repeatedly providing smaller irregularities on the vibration surface. If the coil vibrating body 30D is easily expanded and contracted in the inner direction and the outer direction of the loop, the influence of vibrations at the respective positions of the coil vibrating body is reduced, and a uniform frequency characteristic can be easily obtained.

Next, a first modification of the electroacoustic transducer according to Embodiment 3 will be described.
FIG. 7 is a cross-sectional schematic end view of the main part of the intermediate portion in the height direction of the coil vibrating body showing a first modification of the electroacoustic transducer in the third embodiment.
In FIG. 7, the electroacoustic transducer 10 C in the first modification of the third embodiment is different from the third embodiment in that a plurality of coil vibrating bodies 30 D whose size is smaller than that of the third embodiment are arranged radially. It is a point.
The shape of the coil vibrating body 30D may be increased or decreased toward the front of the magnet plate, and effectively functions as a cylindrical shape. When the diameter is reduced, the valley fold 33y in FIG. 7 becomes the mountain fold 33x.
The plurality of coil vibrating bodies 30D do not need to have the same expanded diameter, reduced diameter, and cylindrical shape as a whole, and can be selected from various combinations of shapes according to required characteristics. Become.
Compared to the electroacoustic transducer 10B of the third embodiment, the electroacoustic transducer 10C can increase the occupation ratio of the conductor 31 and is effective as a means for increasing the utilization efficiency of the magnet.

Next, a second modification of the electroacoustic transducer according to Embodiment 3 will be described.
FIG. 8 is a schematic cross-sectional end view of a main part of the intermediate portion in the height direction of the coil vibrating body showing a second modification of the electroacoustic transducer in the third embodiment.
In FIG. 8, the electroacoustic transducer 10D in the second modification of the third embodiment is different from the third embodiment in that the conductors 31 of the coil vibrating body 30E and the coil vibrating body 30F are bow-shaped or crescent-shaped. It is the point by which the two large and small

coil vibrating bodies

30E and 30F which were deform | transformed by providing the two valley fold parts 33y by the point wound in this way are opposingly arranged so that two may be followed along a circumference. is there.
The shapes of the coil vibrating body 30E and the coil vibrating body 30F may be increased or decreased in diameter toward the front of the magnet plate, and effectively function as a cylindrical shape. When the diameter is reduced, the valley fold 33y in FIG. 8 becomes the mountain fold 33x. Note that the coil vibrating body 30E and the coil vibrating body 30F do not have to have the same expanded diameter, reduced diameter, and cylindrical shape as a whole.
Similarly to the electroacoustic transducer 10C of the first modification, the electroacoustic transducer 10D can increase the occupation ratio of the conductor 31 and is effective as a means for increasing the utilization efficiency of the magnet.

Next, a third modification of the electroacoustic transducer according to Embodiment 3 will be described.
FIG. 9 is a cross-sectional schematic end view of the main part of the middle portion in the height direction of the coil vibrating body showing a third modification of the electroacoustic transducer in the third embodiment.
In FIG. 9, the electroacoustic transducer 10E in the third modification of the third embodiment is different from the third embodiment in that the conductor 31 is wound so that the entire shape of the coil vibrating body 30G is spiral. It is a point that has been turned.
The shape of the coil vibrating body 30G may be increased or decreased toward the front of the magnet plate, and effectively functions as a cylindrical shape. When the diameter is reduced, the valley fold 33y in FIG. 9 becomes the mountain fold 33x.
In one coil vibrating body 30D such as the electroacoustic transducer 10B of the third embodiment, the occupation ratio of the conductor 31 is reduced, and the utilization efficiency of the magnet is reduced. Therefore, the electroacoustic transducer 10C of the first modification example. Alternatively, in the electroacoustic transducer 10D of the second modification, a plurality of

coil vibrating bodies

30D or 30E, 30F are arranged to increase the occupation ratio of the conductor 31. In the electroacoustic transducer 10E of the third modified example, the electroacoustic transducer 10C of the first modified example is formed by stretching the conductor 31 so that the entire shape of the coil vibrating body 30G is spiral. Similarly to the electroacoustic transducer 10D of the second modification, the occupation ratio of the conductor 31 can be increased, which is effective as a means for increasing the utilization efficiency of the magnet.
In addition, the coil vibrating body 30G having a spiral shape can be easily expanded and contracted in an inner direction and an outer direction of the loop by elastic deformation by forming a loop shape while repeatedly providing smaller irregularities on the vibration surface. When the coil vibrating body 30G is easily expanded and contracted in the inner direction and the outer direction of the loop, the influence of the vibrations at the respective positions of the coil vibrating body is reduced, and a uniform frequency characteristic is easily obtained.

Next, a fourth modification of the electroacoustic transducer according to Embodiment 3 will be described.
FIG. 10 is a schematic cross-sectional end view of a main part of the middle part in the height direction of the coil vibrating body showing a fourth modification of the electroacoustic transducer in the third embodiment.
In FIG. 10, the electroacoustic transducer 10F according to the fourth modification of the third embodiment is different from that of the third embodiment in that the coil vibrating body 30H has an elliptical shape at the center and an arcuate or crescent shape on both sides. Is that the conductor 31 is wound so as to form a continuous loop.
The shape of the coil vibrating body 30H may be increased or decreased toward the front of the magnet plate, and effectively functions as a cylindrical shape. In the case of use with a reduced diameter, the valley fold 33y in FIG. 10 becomes a mountain fold 33x, and the mountain fold 33x becomes a valley fold 33y.
Even in one coil vibrating body 30H that is easy to install, the occupied volume of the conductor 31 can be increased by using a plurality of mountain folds 33x and valley folds 33y to deform the shape in a complicated manner, thereby using a magnet. Efficiency can be increased. Further, since the shape of each part of the coil vibrating body is changed as compared with the electroacoustic transducer 10E of the third modified example, the frequency characteristics, directivity characteristics, and efficiency can be improved by using the vibration surface inclination and shape separately for each part. Etc. can be finely adjusted.
Note that the coil vibrating body 30H having an elliptical shape or a bow shape can be easily expanded and contracted in the inner and outer directions of the loop by elastic deformation by forming a loop shape while repeatedly providing smaller irregularities on the vibration surface. When the coil vibrating body 30H is easily expanded and contracted in the inner direction and the outer direction of the loop, the influence of vibrations at the respective positions of the coil vibrating body is reduced, and a uniform frequency characteristic is easily obtained.

According to the electroacoustic transducer in the third embodiment configured as described above, the same operation as in the first embodiment can be obtained.
As described above, the coil vibrator used in the present invention can operate in various shapes and sizes, and can be used in various combinations to constitute an electroacoustic transducer.
Basically, the coil vibrating body easily generates sound if the conductor is wound in a shape other than a circle. Even if it is circular, by forming it in a loop shape while repeatedly providing small irregularities on the vibration surface, it is possible to easily generate sound by expanding and contracting inward and outward of the loop by elastic deformation of the irregularities.

Hereinafter, the present invention will be specifically described by way of examples. The present invention is not limited to these examples.
Example 1
An electroacoustic transducer 10 having the same configuration as that of the first embodiment was created.
<Configuration of magnet plate>
The center region magnet 21 is magnetized in the axial direction by a cylindrical neodymium magnet having an outer diameter of 18 mm, an inner diameter of 5 mm, and a height of 8 mm. The basic area magnet 22 has a cylindrical shape with an outer diameter of 36 mm, an inner diameter of 18 mm, and a height of 8 mm, and an upper base of 2.8 mm, a lower base of 5.6 mm, and a height of 8. Sixteen 7 mm trapezoidal neodymium magnets (small magnets 22b) are combined. The magnet plate 20 was configured by combining the two types of central region magnets 21 and basic region magnets 22.
<Creation of coil vibrator>
First, three conductors 31 made of insulated copper clad aluminum wires having an outer diameter of 80 μm were arranged in parallel and wound into a single ring to form a thin ring with an inner diameter of 20 mm and an outer diameter of 34 mm. Furthermore, an adhesive was applied and fixed on the back side to create a planar coil. Then, the coil vibrating body 30 was created by pressing against a mold formed in the same shape as the coil vibrating body 30 shown in FIG. The diameter of the minimum part of the coil vibrating body 30 was 10 mm, the diameter of the maximum part was 24 mm, the height of the lowest part of the outer peripheral edge part was 5 mm, and the height of the highest part was 8 mm.
<Characteristic>
The impedance of the electroacoustic transducer 10 using the magnet plate 20 and the coil vibrating body 30 configured as described above was 4Ω. The average output sound pressure level (2.83 V / 1 m) between 2.5 kHz and 20 kHz was 85 dB, and both the second and third harmonic distortions in this band were less than 0.3%. It was.
Further, the change of the output sound pressure level in the direction of 30 degrees with respect to the central axis direction was obtained as an average value of −2 dB around 10 kHz and −4 dB around 20 kHz.
In addition, in a speaker with an outer diameter of 24 mm of a voice coil diaphragm manufactured according to (Patent Document 4), the change of the output sound pressure level in the direction of 30 degrees as an average value is −5 dB around 10 kHz and −9 dB around 20 kHz. It was about. Therefore, in this embodiment, the change in the output sound pressure level in the direction of 30 degrees with respect to the central axis is improved by +3 dB around 10 kHz and +5 dB around 20 kHz. Although this embodiment is created as a simple general example of the present invention and is not intended to improve the directivity, the directivity is thus greatly improved.
As described above, the electroacoustic transducer 10 according to the present embodiment uses the vertical magnetic field component of the magnetic field formed by the magnet plate 20 to obtain sufficient results in the directional characteristics, harmonic distortion, output sound pressure level, and the like. It is possible to use a speaker using a high-quality voice coil diaphragm with higher performance.

(Example 2)
When the basic region magnet 22 in Example 1 was abolished and only the central region magnet 21 having an outer diameter of 20 mm was used as the magnet plate 20, a magnetic field distribution state similar to that in Example 1 was obtained in the coil vibrating body 30 part. .
Since the magnetic field intensity at each position of the coil vibrating body 30 is reduced to about half that of the first embodiment, the output sound pressure level is also reduced, but the amount of magnets used can be reduced to about one third.
Thus, the coil vibrating body of the present invention can be operated not only with respect to various magnetic field distributions but also with a very simple magnet plate of only one kind of cylindrical magnet.
In addition, since the entire electroacoustic transducer 10 can be downsized by reducing the size of the magnet plate 20, it can also be used for headphones with high sound quality. In addition, since the structure is simple, it can be suitably used for earphones, microphones, etc. that require precise work by advancing the miniaturization, and easily realize the high sound quality of electroacoustic transducers that employ a voice coil diaphragm. become able to.

The present invention realizes a new vibration form by using not only a parallel magnetic field component of a magnetic field formed by a magnet plate but also a vertical magnetic field component in an electroacoustic transducer adopting a voice coil diaphragm, thereby further increasing the height. It aims at performance and diversification. By using a vertical magnetic field component, we realized a speaker with excellent magnet utilization efficiency and extremely good directivity, and dedicated this high-frequency speaker to the coaxial speaker that is ideal for multiway speakers The magnetic circuit can be installed without providing the magnetic circuit, thereby reducing the overall size and adapting it to various usage forms. In this way, an electroacoustic transducer excellent in sound quality, versatility, mass productivity, and resource saving is provided, and conversion from electrical signals such as speakers, headphones, and earphones to sound, or a microphone, a sound wave sensor Thus, it is possible to contribute to efficiency in conversion from sound to electrical signals.

10, 10A, 10B, 10C, 10D, 10E, 10F Electroacoustic transducer 20 Magnet plate 21

Center area magnet

21a, 53a, 54a Bolt insertion hole 22

Basic area magnet

22a, 54b Sound passage hole

22b Small magnet

30, 30A, 30B , 30C, 30D, 30E, 30F, 30G, 30H Coil vibrator 31

Conductor

33, 33A, 33B, 33C Vibration surface 33x Mountain fold 33y

Valley fold

40, 40A Cylindrical frame 40a Front support frame 40b Opening 41, 41A Inner peripheral

side support part

42, 42A Outer peripheral

side support part

43A, 44A Intermediate support part 45 Sound absorbing material 51 Outer peripheral frame 52 Intermediate frame 53 Central frame 54 Rear frame 56 Bolt 57 Nut

Claims

A magnet plate, and a coil vibrating body formed by winding a conductor and disposed in front of the magnet plate, (a) a magnetic field formed by the magnet plate, and the coil vibrating body An electromagnetic force generated by an acoustic signal current flowing through the conductor causes the coil vibrating body to vibrate to generate sound, or (b) a magnetic field formed by the magnet plate and vibration of the coil vibrating body due to sound. And an electroacoustic transducer for generating an acoustic signal current in the conductor of the coil diaphragm,
The coil vibration body has a vibration surface inclined with respect to the front surface of the magnet plate or a vibration surface perpendicular to the front surface of the magnet plate, and the vibration surface is formed in a loop shape, The electroacoustic transducer is characterized in that the vibration of the above has a component parallel to at least the front surface of the magnet plate.
2. The electroacoustic transducer according to claim 1, wherein the vibration surface of the coil vibrating body is formed in a loop shape while repeating unevenness.
The electroacoustic transducer according to claim 1 or 2, comprising a plurality of the coil vibrating bodies.