WO2010084575A1

WO2010084575A1 - Speaker device and electronic device

Info

Publication number: WO2010084575A1
Application number: PCT/JP2009/050776
Authority: WO
Inventors: 健一廣田
Original assignee: パイオニア株式会社; 東北パイオニア株式会社
Priority date: 2009-01-20
Filing date: 2009-01-20
Publication date: 2010-07-29

Abstract

Provided is a speaker device wherein a desired space can be secured on the lower side of a diaphragm. The device is provided with a magnetic circuit unit (20) which comprises a plate (22) wherein the outer circumference is shaped nearly circularly and the inner circumference is shaped to have a long axis (L) and a short axis (S), and a yoke (24) disposed inside the plate (22); a frame (30) which supports the magnetic circuit unit (20) and has a planar shape having the long axis (L) and the short axis (S), and the diaphragm (2) supported by the frame (30). The plate (22) is provided with a magnet (26), and the distance between the frame (30) and the magnetic circuit unit (20) in the direction of the long axis (L) is longer than in the direction of the short axis (S).

Description

Speaker device, electronic equipment

The present invention relates to a speaker device and an electronic apparatus including the speaker device.

For example, portable electronic devices such as a mobile phone, a portable radio, and a PDA are required to be downsized for the entire device for the purpose of carrying. In addition, for example, display electronic devices such as flat-screen televisions are similarly required to reduce the size of the entire device. Therefore, the speaker device mounted on the electronic device exemplified above needs to have a substantially rectangular shape so that it can be accommodated in a specified space, and further thinning and miniaturization are required. . The speaker apparatus, generally, in order to obtain a less distortion acoustic characteristics over a wide frequency band is required to lower the lowest resonance frequency f ₀

A conventional speaker device for miniaturization has a magnetic circuit unit in which two bar-shaped magnets are sandwiched between a rectangular upper plate and a rectangular lower plate, and the magnetic circuit unit is provided on the lower plate. Some magnets are placed parallel to each other across a bar-shaped center pole. A frame is coupled to the magnetic circuit unit, and a diaphragm is coupled to the outer periphery of the frame. A part of the voice coil coupled to the diaphragm is disposed in a gap (magnetic gap) between the center pole portion and the magnet (see, for example, Patent Document 1).

JP 2004-266337 A (Claim 1, [0027], [0028], [0043], FIGS. 1 and 6)

In some cases, a speaker device mounted on an electronic device such as a mobile phone or a display device has a rectangular planar shape so that it can be stored in a specified space. Therefore, in order to make the magnetic flux density in the magnetic gap relatively large, it is conceivable to make the outer shape of the magnet rectangular and make it relatively large, or to use two bar-shaped magnets as shown in Patent Document 1. . However, in the former case, since the outer shape of the magnet is rectangular, there is a problem that the cost of the magnet becomes relatively large. In the latter case, two rod-shaped magnets are used, and the width of both end portions in the longitudinal direction of the upper plate is formed to be relatively narrow, so that magnetic saturation is positively generated and the space between the upper plate and the center pole portion is increased. A magnetic gap is formed. For this reason, there is a problem that the magnetic flux density in the magnetic gap in the vicinity of the longitudinal end of the upper plate is relatively small.

The present invention has been made in view of the above-described circumstances, and an example of an object is to solve the above-described problems. A speaker device and a speaker apparatus that can solve these problems are provided. It is an object of the present invention to provide an equipped electronic device.

In order to achieve such an object, the present invention comprises at least the configurations according to the following independent claims.
According to a first aspect of the present invention, there is provided a speaker device including a first magnetic pole portion having an outer periphery formed in a substantially circular shape and an inner periphery formed in a shape having a major axis and a minor axis; A magnetic circuit portion having a second magnetic pole portion disposed inside the magnetic pole portion; a stationary portion that supports the magnetic circuit portion and whose planar shape has a major axis and a minor axis; and the stationary portion And the first magnetic pole portion includes a magnet, and the distance between the stationary portion and the magnetic circuit portion in the major axis direction is the distance between the stationary portion and the magnetism in the minor axis direction. It is characterized by being larger than the distance between the circuit portions.

1 is a plan view of a speaker device according to Embodiment 1. FIG. 1 is a perspective view of a speaker device according to Embodiment 1. FIG. FIGS. 2A and 2B are cross-sectional views taken along line AA in FIG. 1, in which FIG. 1A is an example in which the cross-sectional shape of the first reinforcing portion has a substantially triangular shape, and FIG. It is an example in the case of exhibiting a shape. FIG. 3 is a perspective view when a vibrating body is removed from the speaker device according to the first embodiment. 2 is a rear perspective view of the speaker device according to Embodiment 1. FIG. 3 is a partial cross-sectional perspective view when a vibrating body is removed from the speaker device according to Embodiment 1. FIG. It is a top view of the rear surface when only a plate is attached to the flame | frame of the speaker apparatus by Embodiment 1. FIG. It is sectional drawing in the short axis of the speaker apparatus of FIG. It is sectional drawing in the long axis of the speaker apparatus of FIG. 6 is a cross-sectional view of a speaker device according to Embodiment 2. FIG. 6 is a schematic plan view of a speaker device (without a vibrating body) according to Embodiment 2. FIG. It is a top view which shows the structure of the mobile telephone which attached the speaker apparatus based on this invention.

Embodiment 1 FIG.
Embodiments of the present invention will be described below with reference to the drawings. For convenience, the same reference numerals are given to the overlapping parts unless otherwise specified, and detailed description thereof is omitted. The speaker device 1 according to the present embodiment is configured such that a vibrating body 2 and a magnetic circuit unit 20 (see FIG. 8) are supported by a frame 30.

(Vibrating body)
As shown in FIG. 1, the planar shape of the vibrator 2 has a substantially track shape in which a rectangle exists between two arc shapes. The vibrating body 2 is configured by integrally forming a first vibrating portion 2a having a substantially track-shaped planar shape and a second vibrating portion 2b having a circular track-shaped planar shape. The voice coil support portion 5 formed in a flat shape is disposed between the first vibrating portion 2a and the second vibrating portion 2b.

The planar shape of the vibrating body 2 is not limited to a track shape, and is not particularly limited as long as the shape is defined by a major axis and a minor axis, such as an ellipse, a rectangle, and a polygon. Further, the first vibrating portion 2a and the second vibrating portion 2b are not limited to being integrally formed, and the first vibrating portion 2a and the second vibrating portion 2b are formed as separate members. One of the first vibrating portion 2a and the second vibrating portion 2b may be joined to the other by thermocompression bonding or an adhesive. Furthermore, although the example in which the voice coil support portion 5 is formed in a flat shape is shown, the present invention is not limited to this, and for example, the voice coil support portion 5 may be formed in a downward convex shape (pocket shape). In addition, when the voice coil support part is formed in a pocket shape, the voice coil is arranged inside the voice coil support part.

Here, the annular track shape refers to a shape in which a planar shape connects two ends of two arc shapes having a predetermined width with two rectangles having the same width as the arc shape. The first vibrating portion 2a having a substantially track shape located substantially at the center of the vibrating body 2 is extracted. The first vibration part 2a has a curved shape in which a longitudinal cross-sectional shape (a cross section when the vibration body 2 is cut in the vibration direction) protrudes to the front surface (acoustic radiation direction), and has a dome shape. Yes. The second vibrating portion 2b connects two arc-shaped portions (first regions) 2ba and 2bb, and both ends of the arc-shaped portions 2ba and 2bb with the same width as the arc-shaped portions 2ba and 2bb. Two rectangular portions (second regions) 2bc and 2bd are integrally formed. The longitudinal cross-sectional shape of the 2nd vibration part 2b is exhibiting the substantially curvilinear shape protruded to the front surface (acoustic radiation direction) side.

In the present embodiment, the first vibrating portion 2a and the second vibrating portion 2b are both formed in a substantially curved shape in longitudinal section. Further, the top of the first vibrating portion 2a is formed lower than the top of the second vibrating portion 2b. Without being limited thereto, the top of the first vibrating portion 2a may be substantially the same height as the top of the second vibrating portion 2b, or may be changed as appropriate.

The upper end portion of the voice coil 15 is joined to the voice coil support portion 5 formed in a flat shape using an adhesive or the like. Therefore, the voice coil 15 has a track shape with an annular planar shape.

The outer periphery of the second vibrating portion 2b is formed with a folded portion 2c (see FIG. 9) that is folded substantially perpendicularly to the front surface (acoustic radiation direction) side. Since the folded portion 2c is formed, the vibrating body 2 can be easily and accurately assembled to the frame 30 when the speaker device 1 is assembled using the vibrating body 2. That is, the folded portion 2c plays a role of positioning. In addition, since the vibrating body 2 is supported by the frame 30 by the folded portion 2c of the second vibrating section 2b, the second vibrating section 2b also functions as an edge of the vibrating body 2. Moreover, as shown in FIG.8 and FIG.9, the top part 9 of the 2nd vibration part 2b is formed so that it may be located in the outer peripheral part side rather than the center 10 of the inner peripheral part and outer peripheral part. With this configuration, the effective vibration area of the vibrating body 2 can be made relatively large, and the sound pressure can be made relatively large.

By the way, in order to meet the demands for thinning and miniaturization of the above-described speaker device, from the viewpoint of the vibrating body, vibration that vibrates by an electric signal applied to the voice coil and emits a sound wave (hereinafter referred to as “acoustic”). It is conceivable to reduce the weight of the plate, the edge attached to the periphery of the diaphragm and supporting the diaphragm. For example, if the thickness of the diaphragm or the edge is reduced, the weight of the diaphragm or the edge can be reduced.

However, when the thickness of the diaphragm or the edge is reduced, it becomes easy to deform, and naturally the rigidity is reduced. Here, rigidity refers to a physical quantity related to the difficulty of deformation of the structure. If the rigidity of the diaphragm or the edge is reduced, rolling phenomenon and split vibration (split resonance) are likely to occur. As a result, incidental sound increases, abnormal sound is generated, or sound is distorted. , Good sound quality may not be obtained.

Here, the rolling phenomenon means that the vibration system of the speaker device does not move up and down linearly in the sound radiation direction (vibration direction of the voice coil) according to the electrical signal applied to the voice coil, and the sound radiation direction. On the other hand, it means a phenomenon that vibrates in a substantially vertical direction or an oblique direction. The divided vibration (divided resonance) is a phenomenon in which each part of the diaphragm vibrates separately when the diaphragm is bent. Split resonance means that the vibration due to the amplitude motion of the voice coil bobbin spreads concentrically from the center to the periphery of the diaphragm and is reflected by the edge, and then the diaphragm is reversed from the periphery to the center. When transmitting in the direction, it means a phenomenon in which the vibration reflected by this edge interferes with the vibration newly transmitted from the voice coil bobbin to cause resonance.

Therefore, conventionally, in order to improve the rigidity of the edge constituting the vibrating body, a vibrating body having the following structure has been proposed. That is, this vibrating body is formed by integrally forming a diaphragm having a dome shape and an outer peripheral edge, and groove-shaped ribs are integrally formed on the edge. An adjustment member that partially improves the bending strength of the edge is provided on a part of the front surface or the back surface of the edge (for example, Japanese Patent Application Laid-Open No. 2004-048494). Hereinafter, this technique is referred to as a first technical example.

Conventionally, in order to provide a speaker device in which the minimum resonance frequency f ₀ does not increase even if the size is reduced, a vibrator having the following structure has been proposed. That is, in this vibrating body, a first vibrating portion that functions as a diaphragm at the center, a coupling portion to which a voice coil is coupled to the outer periphery, and an edge are integrally provided on the outer periphery. Further, a second vibration part functioning as a diaphragm is provided on the outer peripheral side of the coupling part so as to be connected to the edge (for example, Japanese Patent Laid-Open No. 2006-166070). Hereinafter, this technique is referred to as a second technical example.

Conventionally, even when the area of the dome is large, high-quality sound reproduction is achieved by ensuring sufficient rigidity over the entire area of the dome-shaped diaphragm and reducing disturbances in the high frequency characteristics due to harmonic distortion. In order to make this possible, a vibrator having the following structure has been proposed. That is, this vibrating body is supported by the frame via an edge in which a diaphragm having a dome shape is integrated on the outer periphery thereof. At the edge, reinforcing ribs having a concavo-convex structure are formed on the outer periphery. On the other hand, a reinforcing rib formed by a groove or a bulge extending from the vicinity of the center of the dome toward the outer periphery of the dome is formed radially on the diaphragm (for example, JP-A-2006-287418). Hereinafter, this technique is referred to as a third technical example.

In the first to third technical examples described above, the sound wave propagating from the center of the diaphragm toward the edge due to the vibration of the voice coil and the center of the diaphragm from the edge between the dome-shaped diaphragm and the edge. There is a problem in that reverse resonance (edge hole) caused by the sound wave returning to the portion occurs. This reverse resonance may appear as a high-frequency resonance frequency in the audible range in the acoustic characteristics (sound pressure level-frequency characteristics) of the speaker. As a result, there is a problem in that the acoustic characteristics of the speaker device are reduced, such as distortion in the high sound range and unclear sound quality in the high sound range.

By providing the first reinforcing portion 2a or the second reinforcing portion 2b on the vibrating body 2, which will be described later, taking the above problem as an example, a speaker device having a favorable vibrating body 2 and the vibrating body 2 is provided. Make it possible.

(First reinforcement part)
The first reinforcing portions 6a to 6c that are convex on the front surface (sound radiating direction) side across the first vibrating portion 2a and the second vibrating portion 2b (when collectively referred to as "first reinforcing portion 6") Are formed. In the present embodiment, a total of ten first reinforcing portions 6 are formed, including four first reinforcing portions 6a, four first reinforcing portions 6b, and two first reinforcing portions 6c. . Two first reinforcing portions 6a are arranged in the radial direction from the first vibrating portion 2a to two second regions (rectangular portions 2bc and 2bd) in the vibrating portion 2b, with two short axes S therebetween. Extend. The first reinforcing portion 6b extends in the radial direction from the first vibrating portion 2a toward each corner of the track shape in the second vibrating portion 2b. Further, the first reinforcing portion 6c extends in the radial direction on the long axis L from the first vibrating portion 2a toward the second vibrating portion 2b. These ten first reinforcing portions 6 are arranged substantially evenly in the circumferential direction, and are all formed radially so that the width increases toward the outside. The first reinforcing portions 6 a to 6 c are arranged at positions that are substantially symmetric with respect to the short axis S or the long axis L.

Thus, the first reinforcing portion 6 is formed from the first vibrating portion 2a to the second vibrating portion 2b. Thereby, it becomes possible to make the high frequency resonance frequency accompanying division resonance (including division vibration) out of the audible range, and the acoustic characteristics of the speaker device 1 having the vibration body 2 can be improved. Further, since the first reinforcing portion 6 extends in the track-shaped radial direction, the rigidity at the boundary between the first vibrating portion 2a and the second vibrating portion 2b becomes relatively large, and the entire vibrating body 2 is formed. Can be vibrated in substantially the same phase. As a result, the frequency characteristic of the speaker device having the vibrating body 2 can be made flat. In addition, since the first reinforcing portions 6a to 6c are disposed at positions that are substantially symmetric with respect to the short axis S or the long axis L, it is possible to suppress the occurrence of unnecessary vibration (such as a rolling phenomenon). The entire vibrating body 2 can be vibrated with substantially the same phase.

The planar shape of the first reinforcing portion 6 has a polygonal shape. The planar shape of the first reinforcing portion 6 is not limited to a polygonal shape, and the shape is not particularly limited as long as the rigidity of the vibrating body 2 can be increased, and may be an elliptical shape or a rectangular shape. .

In the present embodiment, the planar shape of each first reinforcing portion 6 has a substantially bowl-like shape (a quadrilateral having two sets with two adjacent sides having the same length). By making the planar shape of each first reinforcing portion 6 polygonal, the first reinforcing portion 6 can be bent in the circumferential direction of the arc-shaped portions 2ba and 2bb, so unnecessary vibration (for example, Occurrence of split resonance, rolling phenomenon, etc. can be suppressed. Further, when the vibrating body 2 vibrates, the first reinforcing portion 6 bends so that the second vibrating portion 2b can follow the vibration of the first vibrating portion 2a.

The cross-sectional shape of the first reinforcing portion 6 may be any of a substantially inverted V shape, a substantially inverted U shape, a substantially rectangular shape, a substantially serrated shape, or a substantially sinusoidal shape. In other words, there is no particular limitation as long as it has a top portion. The top portion may be any shape that can be refracted or bent.

FIG. 3 is a cross-sectional view taken along the line AA in FIG. FIG. 3A shows an example in which the cross-sectional shape of the first reinforcing portion 6 has a substantially inverted V shape, and FIG. 3B shows the cross-sectional shape of the first reinforcing portion 6 having an inverted substantially U shape. It is an example in the case of presenting. In the example of FIG. 3A, the first reinforcing portion 6 has a top portion 43 in contact with a slope 41 and a slope 42 both having a linear shape. On the other hand, in the example of FIG. 3B, the first reinforcing portion 6 has a top portion 46 in contact with the slope 44 and the slope 45 both having a curved shape.

The first reinforcing portion 6 is a wall portion 4 of the second vibrating portion 2b formed in the vicinity of the voice coil support portion formed in a flat plate shape from the front surface (surface on the acoustic emission side) of the first vibrating portion 2a. It extends to. Of the both ends of the first reinforcing part 6, one end is arranged in front of the first vibrating part 2a (surface on the acoustic radiation side), more specifically, near the center position of the first vibrating part 2a. Has been. The other end of the first vibrating portion 6 is disposed on the wall portion 4 of the second vibrating portion 2b. Further, the other end portion of the first vibrating portion 6 may extend outside the wall portion 4 of the second vibrating portion, and is particularly limited as long as the rigidity of the vibrating body 2 can be increased. Not done. Further, the width (circumferential direction) of the first reinforcing portion 6 is gradually reduced from the other end portion of the first reinforcing portion 6 to the one end portion. That is, by reducing the width (circumferential direction) of the first vibrating portion 6 from the outer periphery to the inner periphery of the vibrating body 2, the circumferential vibration (unnecessary vibration) is reduced to the outer peripheral side (first 2 is actively mitigated by the second vibration part 2b), thereby maintaining a constant position on the inner peripheral side (first vibration part 2a) of the vibration body 2 and suppressing the occurrence of unnecessary vibration such as a rolling phenomenon. Can do.

The upper end portion of the first reinforcing portion 6 extends linearly, and the lower end portion thereof has an uneven shape along the shapes of the first vibrating portion 2a, the voice coil support portion 5, and the second vibrating portion 2b. Is formed. Moreover, the cross-sectional shape of the 1st reinforcement part 6 on the wall part 4 of the 2nd vibration part 2b is formed in the substantially triangular shape.

Since both ends of the first reinforcing portion 6 are disposed on the wall portions 4 of the first vibrating portion 2a and the second vibrating portion 2b, the occurrence of vibration in the radial direction of the vibrating body 2 is suppressed, Generation of unnecessary vibration such as a rolling phenomenon can be suppressed.

Further, since a part of the first reinforcing portion 6 is disposed on the voice coil support portion 5, when the voice coil 15 supported by the voice coil support portion vibrates, the vibrating body 2 in the vibration direction. Can be vibrated integrally, and the vibrating body 2, in particular, the first vibrating portion 2a and the second vibrating portion 2b can vibrate at substantially the same phase.

(Second reinforcement part)
The second vibrating portion 2b has a plurality of second reinforcing portions 8a to 8c (collectively referred to as "second reinforcing portions 8") that are convex on the back side (side opposite to the acoustic radiation direction). Is formed. The cross-sectional shape of each second reinforcing portion 8 may be any of a substantially V shape, a substantially U shape, a substantially rectangular shape, a substantially sawtooth shape, or a substantially sinusoidal shape. In other words, there is no particular limitation as long as it has a top portion. The top portion may be any shape that can be refracted or bent.

In the present embodiment, a total of 34 second reinforcing portions 8 are formed, including two second reinforcing portions 8a, 16 second reinforcing portions 8b, and 16 second reinforcing portions 8c. . One second reinforcing portion 8a is provided between the adjacent first reinforcing

portions

6a, 6a, and extends in the radial direction toward the outer periphery. Four second reinforcing portions 8b are provided between the adjacent first reinforcing

portions

6a and 6b, and extend radially toward the outer peripheral side. Four second reinforcing portions 8c are provided between the adjacent first reinforcing

portions

6b, 6c, and extend radially toward the outer peripheral side. In the present embodiment, the first reinforcing portions 6 and the second reinforcing portions 8 are alternately arranged on the drawing. Further, the second reinforcing portion 8 is disposed at a position that is substantially symmetric with respect to the short axis S or the long axis L.

Thus, since the 1st reinforcement part 6 and the 2nd reinforcement part 8 are alternately arrange | positioned, the 1st reinforcement part 6 and the 2nd reinforcement part 8 complement a reinforcement location, and division resonance Generation of (including split vibration) can be suppressed.

Further, the length (in the radial direction) of each second reinforcing portion 8 is slightly shorter than the width of the second vibrating portion 2b. By providing each second reinforcing portion 8, it is possible to adjust the lowest resonance frequency f ₀ to a desired size. That is, if extremely short the length of each second reinforcing portion 8, it may be difficult to adjust the lowest resonance frequency f _0. On the other hand, if the length of each second reinforcing portion 8 is increased, it becomes difficult to bend at the second vibrating portion 2b, so that the vibration is suppressed and the followability to the vibration of the first vibrating portion 2a is impaired. There is. In this example, the minimum resonance frequency f ₀ can be adjusted to a desired size by making the length (radial direction) of each second reinforcing portion 8 slightly shorter than the width of the second vibrating portion 2b. It becomes possible.

Moreover, since the 1st reinforcement part 6 is formed in convex shape at the front surface (acoustic radiation direction) side, the 1st vibration part 2a and the 2nd vibration part 2b vibrate in the mutually opposite direction. The occurrence of split resonance (split vibration), particularly reverse resonance, can be suppressed. Further, since the second reinforcing portion 8 is formed in a convex shape on the back side (the side opposite to the acoustic radiation direction), the rigidity of the second vibrating portion 2b becomes relatively large, and the first vibrating portion 2a. It is possible to relatively increase the followability to the vibration. Moreover, you may form the 2nd reinforcement part 2a suitably in the convex shape in the acoustic radiation side as needed.

The vibrator 2 described above can be integrally formed by, for example, press molding. Examples of the material of the vibrator 2 include paper, a woven fabric using fibers, a knitted fabric using fibers, a nonwoven fabric, a woven fabric using fibers impregnated with a binding resin made of a silicone resin, a metal material, There are synthetic resins, acrylic foams, hybrid materials made of synthetic resins and metals, and the like. Examples of the synthetic resin include polypropylene, polyethylene, polystyrene, polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polycarbonate, polyarylate, epoxy resin, polysulfone, polyurethane having a urethane bond, rubber, and the like. Examples of the metal material include aluminum, titanium, duralumin, beryllium, magnesium, and alloys thereof. The acrylic foam, which is a foamed resin, is formed using, for example, methyl methacrylate, methacrylic acid, styrene, maleic anhydride, and methacrylamide as raw materials. Can be used. The hybrid material is made of, for example, a synthetic resin such as polypropylene and a metal such as tungsten.

Moreover, the vibrating body 2 may have a laminated structure composed of a plurality of layers, for example, a resin film layer composed of polyarylate on a resin film layer composed of polyethylene naphthalate. You may form by stacking.

Further, when the first vibrating portion 2a and the second vibrating portion 2b of the vibrating body 2 are formed of different materials, for example, the first vibrating portion 2a is made of polyethylene naphthalate, and the second vibrating portion 2b is turned on. You may form with rubber | gum etc.

(Voice coil)
The voice coil 15 is joined to the voice coil support portion 5 formed between the first vibrating portion 2a and the second vibrating portion 2b with an adhesive or the like. In this embodiment, the voice coil support portion 5 is formed in a flat shape, but a convex portion extending in the opposite direction to the acoustic radiation direction may be formed as the voice coil support portion 5. The voice coil 5 is joined to the tip of the convex portion with an adhesive or the like.

(Magnetic circuit)
In the present embodiment, the magnetic circuit unit 20 shown in FIGS. 4 to 9 is formed as an outer magnet type configured by combining a plate 22, a yoke 24 and a magnet 26. The magnetic circuit unit 20 is an outer magnet type, but is not particularly limited, and may be an inner magnet type or a magnetic circuit unit using both an outer magnet type and an inner magnet type, and can be appropriately changed. The inner-magnet-type magnetic circuit section here refers to a magnetic circuit section in which a magnet is disposed on the inner side of the voice coil 15, and the outer-magnet-type magnetic circuit section similarly refers to the voice coil 15. Is a magnetic circuit part in which a magnet is arranged outside. The combined use of the inner magnet type and the outer magnet type refers to a magnetic circuit unit in which magnets are arranged inside and outside the voice coil.

The planar shape of the plate 22 is an annular plate shape having a substantially circular outer periphery and a track shape on the inner periphery (see FIG. 7). In other words, the inner periphery of the plate 22 has a shape defined by the major axis and the minor axis. The plate 22 is made of a magnetic material such as pure iron, oxygen-free steel, or silicon steel.

As with the plate 22, the magnet 26 has an annular plate shape with a substantially circular outer periphery and a substantially track inner periphery. The outer diameter and inner diameter of the magnet 26 are formed larger than the plate 22 and are larger than the whole (see FIGS. 8 and 9). The magnet 26 is made of, for example, a permanent magnet such as neodymium-based, samarium-cobalt-based, alnico-based, or ferrite-based magnet.

8 is a cross-sectional view of the speaker device 1 along the short axis S, and FIG. 9 is a cross-sectional view of the speaker device 1 along the long axis L. The yoke 24 includes an annular plate-shaped bottom portion 24a having a substantially circular outer periphery and a substantially track-shaped inner periphery, and a pole portion 25 protruding from the inner peripheral edge of the bottom portion 24a toward the front surface (acoustic radiation direction). The pole portion 25 includes a cylindrical portion 24b extending right above the inner peripheral edge of the bottom surface by the height of the magnet 26 and the plate 22, and an upper surface portion 24c covering the upper edge of the cylindrical portion 24b. A vent hole 24d is provided at the center of the portion 24c. The planar shape of the upper surface portion 24 c is a track shape that is slightly smaller than the inner periphery of the plate 22. The magnet 26 and the plate 22 are formed such that a width 22L (see FIG. 9) from the outer circumference to the inner circumference in the major axis direction L is smaller than a width 22S (see FIG. 8) from the outer circumference to the inner circumference in the minor axis direction S. Has been. On the other hand, the upper surface portion 24c of the yoke 24 is formed such that the width 24L from the outer periphery to the inner periphery in the major axis direction L is larger than the width 24S from the outer periphery to the inner periphery in the minor axis direction S. The width 24S from the outer circumference to the inner circumference in the minor axis direction S of the upper surface portion 24c of the yoke 24 is formed to be larger than the width 22S from the outer circumference to the inner circumference in the minor axis direction S of the plate 22. The width 24L from the outer circumference to the inner circumference in the major axis direction L of the upper surface portion 24c of the yoke 24 is formed to be twice or more larger than the width 22L from the outer circumference to the inner circumference in the major axis direction L of the plate 22. The The yoke 24 is made of a magnetic material such as pure iron, oxygen-free steel, or silicon steel.

As shown in FIGS. 8 and 9, the bottom 24 a of the yoke 24 is provided with a recess 24 e along the shape of the inner peripheral portion of the magnet 26, for positioning the magnet 26 at a predetermined position of the yoke 24. It is formed as a positioning part. The shape of the recess 24e is substantially the same as the track shape of the inner periphery of the magnet 26, and the short axis and the long axis of the track shape of the pole portion 25 of the yoke 24 and the track shape of the recess 24e overlap each other. The magnet 26 is joined to the bottom 24a of the yoke 24 by an adhesive or the like, and the plate 22 is joined to the upper surface of the magnet 26 by an adhesive or the like, whereby the magnetic circuit part 20 is configured. At this time, the short axis and the long axis of the track shape of the pole portion 25 of the yoke 24, the track shape of the inner periphery of the magnet 26, and the track shape of the inner periphery of the plate 22 are arranged so as to all overlap. In the magnetic circuit unit 20 configured as described above, the planar shape of the upper surface portion 24c of the yoke 24 (pole portion 25) is a track shape that is slightly smaller along the inner periphery of the plate 22, so that the upper surface portion A constant gap is formed between 24 c and the plate 22, and this gap becomes a magnetic gap G.

Of the magnetic pole portions constituting the magnetic gap G, the magnetic pole portion disposed outside the magnetic gap G is referred to as a first magnetic pole portion, and the magnetic pole portion disposed inside is referred to as a second magnetic pole portion. In the present embodiment, for example, the plate 22 constituting the magnetic gap G is the first magnetic pole part, and the upper surface part 24c of the pole part 25 is the second magnetic pole part.

Thus, by providing the annular plate-like magnet 26 that continuously forms the first magnetic pole portion in a circumferential shape, the magnetic gap is generated without causing magnetic saturation in the minor axis direction of the first magnetic pole portion. The magnetic flux density in G can be made relatively large. Further, by using a magnet having a circular outer shape, the cost can be made relatively smaller than when a magnet having a rectangular outer shape is used, and the cost of the speaker device can be reduced.

(flame)
As shown in FIGS. 8 and 9, the magnetic circuit unit 20 is supported by a frame 30 that surrounds the periphery of the magnetic circuit unit 20. The frame 30 includes a cylindrical portion 31 that surrounds and supports the periphery of the magnetic circuit portion 20, a support portion 33 that supports the diaphragm 2, and a bottom surface portion 32 provided between the cylindrical portion 31 and the support portion 33. It has a shape with. The cylindrical portion 31 of the frame 30 includes a step portion 34 to which the outer peripheral edge of the magnet 26 is fixed, and a step portion 36 to which the outer peripheral edge of the plate 22 is fixed. The support portion 33 of the frame 30 includes a step portion 38 to which the folded portion 2 c of the second vibration portion 2 b constituting the vibrating body 2 is attached, and the outer periphery of the step portion 38 is surrounded by the side surface portion 37. The step portion 38 is formed with a fitting portion 38a on the inner side for fitting and fixing the folded portion 2c. With such a configuration, the magnet 26 and the plate 22 constituting the magnetic circuit unit 20 are fixed to the frame 30, and the vibrating body 2 is fixed to the frame 30. At this time, the voice coil 15 joined to the vibrating body 2 is inserted into the magnetic gap G.

When the magnetic circuit unit 20 is fixed to the frame 30, the short axis and the long axis of the track shape of the magnetic circuit unit 20 (for example, the inner periphery of the plate 22) and the track shape of the frame 30 are all overlapped. Here, as shown in FIG. 7, linear notches 22a are formed at both ends of the plate 22 in the short axis direction, and linear guides are similarly formed at both ends of the step portion 36 of the frame 30 in the short axis direction. 36a is formed. Accordingly, the planar shape of the plate 22 and the planar shape of the stepped portion 36 are substantially matched, so that when the magnetic circuit portion 20 is fixed to the frame 30, the notch portion 22a and the guide 36a are combined, and the plate 22 is fitted to the frame 30. Accordingly, it is easy to position the magnetic circuit portion 20 and the frame 30 so that the long axis and the short axis of the track shape overlap each other. In addition, although the example which is linear about the notch part 22a and the guide 36a was shown, as long as it is effective as a guide, it may be any shape such as a curved shape or a wave shape.

Since the outer diameter of the cylindrical portion 31 of the frame 30 and the length of the support portion 33 in the minor axis direction are substantially equal, as shown in FIGS. The distance 30L to the circuit unit 20 is longer than the distance 30S from the outer periphery of the frame 30 to the magnetic circuit unit 20 in the minor axis direction S. Therefore, the bottom surface portion 32 of the frame 30 is formed to be wide in the major axis direction of the track shape and narrow in the minor axis direction. Thereby, the bottom face part 32 can be provided widely in the major axis direction. The bottom surface portion 32 can be provided with a speaker terminal portion (not shown) and the like. The bottom surface portion 32 can be provided with a vent hole 39 communicating with the outside. For example, four vent holes 39 having a shape that expands from the outer peripheral side toward the inner side can be provided in the corner portion of the track, whereby the lowest resonance frequency f ₀ can be lowered.

The outer periphery of the frame 30 is provided with a terminal portion 35 for attachment to a device or the like on one end side in the long axis direction.

The frame 30 is made of, for example, a ferrous metal, a non-ferrous metal, an alloy thereof, a synthetic resin, or the like. Examples of the iron-based metal include pure iron, oxygen-free steel, and silicon steel. Examples of the non-ferrous metal include aluminum, magnesium, and zinc. Examples of the synthetic resin include thermoplastic resins such as olefins such as polypropylene, ABS (acrylonitrile / budadiene / styrene), and polyethylene terephthalate. The frame is formed by, for example, drawing a ferrous metal, die casting a non-ferrous metal or an alloy thereof, or injection molding a synthetic resin.

Note that the frame 30 is also a stationary part arranged in a stationary state with respect to the voice coil support part 5. The stationary portion is not intended to be completely stationary. For example, the stationary portion may be stationary so that the diaphragm 2 can be supported, and vibration generated when the speaker device 1 is driven propagates. Vibrations may occur throughout the stationary part. In addition to the frame 30, the stationary portion referred to here corresponds to a part of the magnetic circuit unit 20, a place where the speaker device 1 is attached, and the like.

Further, the stationary part only needs to be mechanically integrated with the magnetic circuit unit 20 described later, and the frame 30 can be said to be supported by the magnetic circuit unit 20, so that it becomes a stationary unit. Therefore, for example, a constituent member constituting the magnetic circuit unit 20 or a member supported by the magnetic circuit unit 20 can be a stationary portion.

Embodiment 2. FIG.
FIG. 10 shows a cross-sectional view of the speaker device 101 according to the second embodiment. FIG. 11 is a plan view schematically showing the relationship between the magnetic circuit unit 120 and the frame 30. Note that the same or corresponding parts as those in the first embodiment are denoted by the same reference numerals as those in FIGS. 1 to 9, and only the configuration different from that in the first embodiment will be described.

(Vibrating body)
The vibrating body 102 is different from the vibrating body 2 in the longitudinal cross-sectional shape of the second vibrating portion 102b provided on the outer periphery, and the other configuration is the same as that of the vibrating body 2. The vertical cross-sectional shape of the second vibrating portion 102b has a substantially curved shape protruding toward the front surface (acoustic radiation direction), and the top portion 109 is the center 10 between the inner peripheral portion and the outer peripheral portion of the second vibrating portion 102b. Located in.

(Magnetic circuit part)
The magnetic circuit unit 120 is configured by combining an outer plate 122, an inner plate 125, a yoke 124, an outer magnet 126 and an inner magnet 123. The outer plate 122 is the same as the plate 22 and has an annular plate shape whose outer periphery is substantially circular and whose inner periphery is substantially track-shaped. The inner plate 125 has a substantially track-shaped outer periphery and is provided with a vent hole 125a in the center and has the same planar shape as the upper surface portion 24c.

Note that a sound absorbing material 140 made of a porous material such as urethane foam or glass wool is provided above the vent hole 125a. As a result, standing waves in the space inside the diaphragm 102b can be reduced, and better acoustic characteristics can be obtained. The yoke 124 has a substantially circular outer periphery, and has an annular plate shape with a vent hole 124a provided at the center. The diameter of the air hole 124a is substantially the same as that of the air hole 125a. The outer magnet 126 is the same as the magnet 26, and has an annular plate shape whose outer periphery is substantially circular and whose inner periphery is substantially track-shaped. The outer diameter and inner diameter of the outer magnet 126 are larger than those of the outer plate 122, and are larger than the whole. The inner magnet 123 has substantially the same shape as the inner plate 125, the outer periphery has a substantially track shape, and a vent hole 123a is provided in the center. The outer diameter of the inner magnet 123 is smaller than the inner plate 125, and the vent hole 123a is smaller than the vent hole 125a.

The track shape of the outer periphery of the inner plate 125, the track shape of the outer periphery of the inner magnet 123, the track shape of the inner periphery of the outer plate 122, and the track shape of the inner periphery of the outer magnet 126 are arranged so that the short axis and the long axis all overlap. In addition, the magnetic circuit unit 120 is configured by joining the center of the yoke 124 with the center of the yoke 124 by an adhesive or the like. In the magnetic circuit unit 120 configured as described above, the planar shape of the inner plate 125 is a track shape that is slightly smaller along the inner periphery of the outer plate 122. A certain gap is formed between them, and this gap becomes a magnetic gap G. Therefore, the outer plate 122 becomes the first magnetic pole part, and the inner plate 125 becomes the second magnetic pole part.

In the second embodiment, as shown in FIG. 10 and FIG. 11, an inner magnet 123 and an outer magnet 126 are provided as magnets, and an inner plate 125 and an outer plate 122 are provided as plates. The outer magnet 126 and the outer plate 122 are formed such that a width 122L from the outer periphery to the inner periphery in the major axis direction L is smaller than a width 122S from the outer periphery to the inner periphery in the minor axis direction S. In contrast, the inner magnet 123 and the inner plate 125 are formed such that a width 125L from the outer periphery to the inner periphery in the major axis direction L is larger than a width 125S from the outer periphery to the inner periphery in the minor axis direction S. Further, the width 125S from the outer circumference to the inner circumference in the minor axis direction S of the inner magnet 123 and the inner plate 125 is larger than the width 122S from the outer circumference to the inner circumference in the minor axis direction S of the outer magnet 126 and the outer plate 122. Formed. The width 125L from the outer circumference to the inner circumference in the major axis direction L of the inner magnet 123 and the inner plate 125 is twice or more than the width 122L from the outer circumference to the inner circumference in the major axis direction L of the outer magnet 126 and the outer plate 122. It is formed to be large. Further, the sum of the width 122L from the outer circumference to the inner circumference in the major axis direction L of the outer magnet 126 and the outer plate 122 and the width 125L from the outer circumference to the inner circumference in the major axis direction L of the inner magnet 123 and the inner plate 125 is The width 122S from the outer circumference to the inner circumference in the minor axis direction S of the outer magnet 126 and the outer plate 122 is substantially equal to the sum of the width 125S from the outer circumference to the inner circumference in the minor axis direction S of the inner magnet 123 and the inner plate 125. .

In the first embodiment in which there is only one magnet, the magnetic flux density in the magnetic gap G is relatively small in the long axis direction in which the width of the magnet 26 is narrower than in the short axis direction in which the width of the magnet 26 is wide. However, in the second embodiment, the magnetic flux density in the magnetic gap G in the major axis direction can be made relatively high in the second embodiment, and the magnetic flux density in the magnetic gap G can be made substantially uniform in the circumferential direction. .

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, each of the above-described embodiments can divert each other's technology as long as there is no particular contradiction or problem in its purpose and configuration.
For example, although the example of the track shape is shown as the inner periphery of the first magnetic pole part and the outer periphery of the second magnetic pole part, it is not limited to this. For example, any material may be used as long as it has a major axis and a minor axis, such as an ellipse, a rhombus, and a rectangle.

The

speaker devices

1 and 101 according to the first and second embodiments are used by being mounted on a portable electronic device (display device) such as a mobile phone, a portable radio, or a PDA. For example, the mobile phone 200 has a plurality of operation buttons 202, a display unit 203, a mouthpiece 204 and a mouthpiece 205 provided on the front side of the case 201, and a function for sounding an incoming call alarm sound provided on the back side of the case 201. , And a transmission / reception antenna 207 provided on one side surface of the case 201. Here, the speaker device 1 (101) is provided in the case 201 at a position corresponding to the position of the earpiece 204 and the incoming call unit 206.

Claims

A first magnetic pole portion having an outer periphery formed in a substantially circular shape and an inner periphery formed in a shape having a major axis and a minor axis; and a second magnetic pole portion disposed inside the first magnetic pole portion; A magnetic circuit unit having
A stationary part that supports the magnetic circuit part and whose planar shape has a major axis and a minor axis;
A vibrating body supported by the stationary part,
The first magnetic pole portion includes a magnet,
The speaker device according to claim 1, wherein a distance between the stationary part and the magnetic circuit part in the major axis direction is larger than a distance between the stationary part and the magnetic circuit part in the minor axis direction.
2. The speaker according to claim 1, wherein the first magnetic pole portion has a distance from the outer circumference to the inner circumference in a major axis direction that is smaller than a distance from the outer circumference to the inner circumference in a minor axis direction. apparatus.
The outer periphery of the second magnetic pole part is formed along the inner periphery of the first magnetic pole part,
The speaker device according to claim 2, wherein a magnetic gap is formed between the first magnetic pole part and the second magnetic pole part.
The second magnetic pole portion includes a magnet;
The speaker device according to claim 3, wherein a width of the second magnetic pole portion in the major axis direction is larger than a width of the second magnetic pole portion in the minor axis direction.
5. The speaker device according to claim 4, wherein a width of the second magnetic pole portion in the minor axis direction is larger than a width of the first magnetic pole portion in the minor axis direction.
5. The speaker device according to claim 4, wherein a width of the second magnetic pole portion in the long axis direction is larger than twice a width of the first magnetic pole portion in the long axis direction.
The speaker device according to claim 6, wherein a vent hole communicating with the outside is formed in the stationary portion outside the magnetic circuit portion.
The stationary part includes a cylindrical part that supports the magnetic circuit part, and a bottom part that supports the vibrating body,
The vent hole extends inwardly from the outer peripheral portion of the bottom surface portion in the stationary portion, and the width of the vent hole on the inner side from the outer peripheral portion side of the bottom surface portion is formed smaller. The speaker device according to claim 7.
The vibrating body includes a first vibrating portion and a second vibrating portion that supports the first vibrating portion on the stationary portion,
A first reinforcing portion extending in the radial direction is formed from the first vibrating portion to the second vibrating portion,
The second vibrating portion is formed with a second reinforcing portion extending in the radial direction,
The first reinforcing portion is formed in a convex shape on the acoustic radiation direction side,
The speaker device according to claim 8, wherein the second reinforcing portion is formed in a convex shape on the side opposite to the acoustic radiation direction.
The vibrating body includes a first vibrating part and a second vibrating part that supports the first vibrating part on the stationary part,
A first reinforcing portion extending in the radial direction is formed from the first vibrating portion to the second vibrating portion,
The second vibrating portion is formed with a second reinforcing portion extending in the radial direction,
Each cross-sectional shape of the first vibrating portion and the second vibrating portion has a curved shape,
The speaker device according to claim 8, wherein a top portion of the first vibrating portion is lower than a top portion of the second vibrating portion.
The speaker device according to claim 9 or 10, wherein the vibrating body supports a voice coil between the first vibrating portion and the second vibrating portion.
The said vibrating body is formed with a voice coil support part for supporting the voice coil between the first vibrating part and the second vibrating part. Speaker device.
The voice coil support part is formed in a flat shape,
The speaker device according to claim 12, wherein an upper end portion of the voice coil is joined to the voice coil support portion.
The second vibrating section includes a first region in which the inner periphery and the outer periphery are linear, and a second region in which the inner periphery and the outer periphery are curved,
The speaker device according to claim 13, wherein a plurality of the second reinforcing portions are formed in the second region.
The second vibrating section includes a first region in which the inner periphery and the outer periphery are linear, and a second region in which the inner periphery and the outer periphery are curved,
The speaker device according to claim 13, wherein a part of the first reinforcing portion is formed in the second region.
The speaker device according to claim 13, wherein the first reinforcing portion and the second reinforcing portion are alternately arranged.
The speaker device according to claim 16, wherein the first reinforcing portion has a polygonal planar shape.
The speaker device according to claim 17, wherein a top portion of the second vibrating portion is located on an outer peripheral side with respect to an intermediate point between the inner periphery and the outer periphery.
The speaker device according to claim 17, wherein a folded portion is formed on an outer periphery of the second vibrating portion.
An electronic apparatus comprising the speaker device according to claim 1.