JP2008182394A - Electroacoustic transducer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electroacoustic transducer which is configured to be thin, sufficiently secures strength and does not adversely affect an antenna which is other electronic component to be loaded on an external apparatus, in the electroacoustic transducer configured so as to be loaded on the external apparatus. <P>SOLUTION: The electroacoustic transducer 10 is configured so as to be loaded on the external apparatus, the cover member 24 is formed of a resin, and further a rib 25 is formed on the surface facing the edge part 12B of a diaphragm 12 of the cover member 24. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electroacoustic transducer configured to be mounted on an external device.

  Generally, an electroacoustic transducer such as a small microphone or a speaker (receiver) is configured to be mounted on an external device. At that time, more and more devices are mounted and used in the housing of external devices. An example of the external device is a mobile phone. In the mobile phone, in addition to the electroacoustic transducer, various electronic components such as a liquid crystal panel, an antenna, and a battery are incorporated. In recent mobile phones, the thickness has been reduced, and the electronic components that are installed in accordance with the reduction in thickness have been demanded. The electroacoustic transducer is also in a situation where there is a growing demand for thinning. Moreover, even if the electroacoustic transducer is made thin, its durability, impact strength, and acoustic characteristics still require the same quality as before. In the case of an electroacoustic transducer, a diaphragm is an example of a weak portion. In order to protect the diaphragm, a cover member on the surface of the diaphragm is essential.

  For example, “Patent Document 1” describes a stainless steel cover member as a cover member on the surface of the diaphragm. In this way, the diaphragm is protected by the sturdy stainless steel cover member, and damage to the diaphragm is prevented.

  The speaker described in “Patent Document 2” is a large speaker, but a speaker that is reinforced with a thick resin grille to cover the entire surface of the diaphragm is disclosed.

JP 2002-354582 A Japanese Patent Laid-Open No. 8-23592

  The speaker described in the above-mentioned “Patent Document 1” is excellent in strength because it has a stainless steel cover member, and has conventionally been used as an electroacoustic transducer installed in a mobile phone.

  However, in recent mobile phones, the antenna is also reduced in size and thickness due to the reduction in thickness, and accordingly, the stainless steel cover member of the speaker, which has not been affected in the past, has a negative effect that the radio wave reception sensitivity is lowered. It has come to come out.

  Along with this, it has become necessary to change the stainless steel cover member of the speaker to a resin cover member. However, if the resin cover member is thinned, the strength may be reduced. Further, it is possible to reinforce and increase the strength as in the speaker described in the above-mentioned “Patent Document 2”, but in the case of a small speaker, unlike the large-sized speaker described in “Patent Document 2”, Since there is only a minute gap between the diaphragm and the cover member, it is difficult to reinforce the entire surface of the diaphragm to be thick.

  The present invention has been made in view of such circumstances, and in an electroacoustic transducer configured to be mounted on an external device, the external device can be configured to be thin and have sufficient strength. It is an object of the present invention to provide an electroacoustic transducer that does not adversely affect an antenna which is another electronic component mounted on the antenna.

  In the present invention, the above object is achieved by devising the structure of the cover member.

  That is, the electroacoustic transducer according to the present invention includes a flat portion at the center, a diaphragm having an edge portion around the flat portion, an additional plate placed on the flat portion at one end of the diaphragm, One end is fixed to the other end of the diaphragm, and a voice coil configured by winding a conducting wire; a magnetic circuit unit in which a magnetic gap for accommodating the other end of the voice coil is formed; A speaker comprising: a housing for protecting a magnetic circuit unit; and a cover member attached to the housing and covering a part of the magnetic circuit unit; wherein the cover member is formed of a resin, and the cover The electroacoustic transducer is characterized in that a beam portion is formed on at least a surface of the member facing the edge portion of the diaphragm.

  The edge portion is curved so as to protrude toward the other end portion of the diaphragm.

  Further, the beam portion is formed on the upper surface side of the diaphragm on the outer periphery of the additional plate mounting portion.

  The beam portion includes at least an annular ring rib surrounding the outer peripheral portion of the additional plate.

  Furthermore, the cover member is formed in a substantially quadrangular shape, and the beam portion includes radiation ribs that extend from the center and corner portions of the cover member to the annular rib. .

Further, the cover member is made of a resin having a thickness of 0.2 mm or less.

  As shown in the above configuration, the electroacoustic transducer according to the present invention has a configuration that can be mounted on an external device, but the cover member is formed of resin and further faces the edge portion of the diaphragm of the cover member. Since the beam portion is formed on the surface to be performed, the following effects can be obtained.

  That is, by forming the cover member from resin, it is possible to prevent the adverse effect on the antenna, which is another electronic component, when it is placed on a mobile phone or the like, and to further improve the strength of the cover member by forming a beam portion. Thus, the resin cover member can be formed thin.

  As described above, according to the present invention, in an electroacoustic transducer configured to be mounted on an external device, a product that does not adversely affect other electronic components and has sufficient durability is provided. be able to.

  In addition, since the edge portion of the diaphragm is curved so as to protrude to the other end side, that is, the lower surface side of the diaphragm, even if a beam portion is formed on the edge portion, it is caused by vertical movement accompanying the ringing of the diaphragm. The possibility that the edge portion interferes with the beam portion can be reduced, and stable acoustic vibration can be obtained.

  Furthermore, since the beam part is formed on the upper surface side of the diaphragm on the outer periphery of the additional plate mounting part, the additional plate protrudes to the cover member side from the diaphragm, but it is added by the vertical movement accompanying the ringing of the diaphragm. Stable acoustic vibration can be obtained without worrying that the plate contacts the beam.

  In addition, since the beam portion has an annular ring rib so as to surround at least the outer peripheral portion of the additional plate, the strength near the center of the cover member on the upper surface side of the additional plate without the beam portion can be improved.

  Furthermore, the cover member of the present invention can be applied to an electroacoustic transducer formed in a substantially square shape. At that time, the beam portion is configured to extend to the annular rib at least from the side center and corner portion of the cover member, so that the strength of the cover member can be improved efficiently only by forming a small number of beams. it can.

Moreover, the effect of said beam part becomes large by applying this invention to the cover member formed with resin whose thickness is 0.2 mm or less.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is an exploded perspective view showing an electroacoustic transducer 10 according to an embodiment of the present invention. Moreover, FIG. 2 is sectional drawing of the electroacoustic transducer 10 which concerns on one Embodiment of this invention.

  As shown in these drawings, the electroacoustic transducer 10 according to the present embodiment is a small electrodynamic speaker, and is used by being incorporated in a housing of an external device (for example, a mobile phone or an IC recorder). It is configured.

  This electroacoustic transducer 10 is a substantially rectangular electroacoustic transducer having a rectangular outer shape with a long side of about 11 mm and a short side of about 7 mm, and a diaphragm 12 that is slightly smaller than the outer shape, and this vibration. A voice coil 14 fixed to the lower surface of the plate 12, a magnetic circuit unit 16 in which an annular magnetic gap for accommodating the lower end of the voice coil 14 is formed, and the magnetic circuit unit 16 is contained and fixedly supported; A frame 20 that fixes and supports the outer peripheral edge of the diaphragm 12 on the upper surface, a pair of terminal plates 18 attached to the frame 20, and a frame 1 that is supported by the frame so as to be exposed from the lower end of the frame 20. It consists of a pair of external connection terminals 22 and a cover member 24 fixed to the frame 20 from the upper surface side of the diaphragm 12.

  In the electroacoustic transducer 10, the voice coil 14 and the magnetic circuit unit 16 constitute a conversion unit for performing electroacoustic conversion via the vibration of the diaphragm 12.

  The frame 20 is an injection-molded product made of a synthetic resin, and has a substantially rectangular outer peripheral surface shape. A circular opening 20D having a slightly larger diameter than the voice coil 14 is formed at the center thereof. ing. The frame 20 includes a frame bottom surface portion 20A positioned around the circular opening 20D, an upper flange portion 20B extending to the upper surface side of the frame bottom surface portion 20A, and a lower flange portion 20C extending to the lower surface side.

  The upper flange portion 20B has a stepped upper surface. That is, on the upper surface of the upper flange portion 20B, approximately half of the upper portion near the inner periphery is the lower step portion 20E, and approximately one-quarter portion adjacent to the outer periphery side is the upper step portion 20F, and the remaining approximately four adjacent to the outer periphery side. The one-half portion is configured as a middle step portion 20G, and the diaphragm 12 is bonded and supported at the lower step portion 20E.

  The outer peripheral surface of the upper flange portion 20B is formed in a substantially rectangular shape. In addition, notches 20H that are notched to the upper surface of the frame bottom surface 20A are formed at the center of both the left and right sides of the upper flange portion 20B. Each notch 20H has a cover member 24 described later. The case fitting portion 24C is adhered.

  The outer peripheral surface of the lower flange portion 20C is formed in a substantially rectangular shape. Further, the magnetic circuit unit 16 is disposed inside the lower flange portion 20C, and the magnet 30 is brought into contact therewith.

  The diaphragm 12 is formed by subjecting a synthetic resin film such as polyimide to hot press molding. A substantially rectangular annular outer peripheral plane portion 12A is formed on the outer peripheral portion of the diaphragm 12, and an edge portion 12B is formed on the inner peripheral side of the outer peripheral plane portion 12A. And this edge part 12B is formed so that it may bulge in the shape of an annular surface toward the lower surface side. Furthermore, a substantially track-shaped central plane portion 12C is formed on the inner peripheral side of the edge portion 12B.

  The diaphragm 12 is bonded to the lower step portion 20E of the upper flange portion 20B of the frame 20 at the outer peripheral plane portion 12A, and is bonded to the upper end of the voice coil 14 at the center plane portion 12C.

  Each of the pair of terminal plates 18 is configured as a processed product of a metal plate, and is integrally formed with the frame 20 by insert molding. Each terminal plate 18 is a land portion that is exposed flush with the upper surface of the frame bottom surface portion 20A at a position adjacent to the short side of the frame bottom surface portion 20A of the frame 20, and the terminal flange 18 of the upper flange portion 20B. It is configured integrally with the external connection terminal 22 exposed on the side surface.

  The voice coil 14 is wound in a cylindrical shape, and is disposed in the circular opening 20 </ b> D of the frame 20. The pair of coil terminals extending from the upper end portion of the voice coil 14 are conductively fixed to the pair of terminal plates 18 by thermocompression bonding.

  Each of the pair of external connection terminals 22 is a metal plate-like terminal member, and is disposed in the vicinity of the pair of terminal plates 18.

  The magnetic circuit unit 16 includes a base 28 made of a magnetic material such as iron, a magnet 30, and a yoke 32 made of a magnetic material such as iron.

  The base 28 is formed in a short bottomed cylindrical shape. The magnet 30 and the yoke 32 are both formed in a disk shape, and are placed on the bottom surface of the base 28 so as to be concentric with each other in this order, and are sequentially bonded together. Thus, a cylindrical magnetic gap for accommodating the lower end portion of the voice coil 14 is formed between the outer peripheral surface of the yoke 32 and the inner peripheral surface of the base 28 with the same width on the entire circumference.

  On the bottom surface of the base 28, a plurality of through holes 28A penetrating the bottom surface of the base 28 in the vertical direction are formed at predetermined intervals in the circumferential direction.

  The magnetic circuit unit 16 is attached to the frame 20 by adhering the upper end of the base 28 to the circular opening 20D of the frame 20 from the lower surface side.

  FIG. 3 is a perspective view of the cover member 24 as seen from the lower surface side. FIG. 4 is an exploded perspective view showing a part of the electroacoustic transducer 10 according to an embodiment of the present invention. 3 and 4 are views from the lower surface side, the upper side of the drawing is the lower surface side and the lower side is the upper surface side.

  As shown in FIGS. 3 and 4, the cover member 24 is an injection molded product made of synthetic resin, and includes a cover body 24 </ b> A, a sound emitting hole 24 </ b> B, a case fitting portion 24 </ b> C, an outer peripheral surface 24 </ b> D, and a rib 25. ing.

  The cover main body 24 </ b> A is formed in a substantially rectangular shape in plan view, and has an outer peripheral surface 24 </ b> D having substantially the same outer shape as the frame 20. The cover main body 24A is formed in a horizontal plane on the upper surface side of the cover main body 24A, and two sound emitting holes 24B are formed in the vicinity of the substantially central portion thereof.

  A plurality of beam-like ribs 25 having a thickness of about 0.15 mm are formed on the lower surface side of the cover main body 24A, and an outer peripheral rib 25A adjacent to the outer peripheral side, and extends from the outer peripheral rib 25A to the central portion. The plurality of radiating ribs 25B and an annular rib 25C formed further on the inner peripheral side of the radiating ribs 25B.

  Further, on the outer peripheral side of the outer peripheral rib 25A, an outer peripheral surface 24D for ultrasonic welding with the upper step portion 20F of the frame 20 is formed in an annular shape. In assembling the electroacoustic transducer 10, when the frame 20 and the cover member 24 are ultrasonically welded, the upper step portion 20F is welded to the outer peripheral surface 24D, and the cover member 24 is fixed to the frame 20.

  Further, a case fitting portion 24C for positioning with the frame 20 is provided in a part of the outer peripheral surface 24D. The case fitting portion 24 </ b> C is a substantially quadrangular protruding member that protrudes from the cover main body 24 </ b> A, and is fitted into a notch portion 20 </ b> H formed in the frame 20.

  Note that portions where the ribs 25 such as the outer peripheral surface 24D of the cover main body 24A are not formed are set to a thickness of about 0.2 mm.

  The plurality of beam-like ribs 25 that are beam portions will be described. First, the outer peripheral rib 25A is provided on the upper surface side of the lower step portion 20E that is the movable outside of the diaphragm 12. Thereby, even if the diaphragm 12 operates, it does not interfere with the outer peripheral rib 25A.

  Next, the radiating ribs 25B are extended from a total of eight locations toward the center of the cover main body 24A from the four corners of the cover main body 24A having a substantially rectangular shape and the vicinity of the center of the four sides. An edge portion 12B is formed on the lower surface side of the radiation rib 25B. Since the edge portion 12B bulges in an annular shape toward the lower surface side, the radiating rib 25B and the diaphragm 12 are configured not to interfere with each other even when the diaphragm 12 is operated. Yes.

The annular rib 25C is a track-like rib member disposed slightly outside the upper surface on the outer peripheral side of the additional plate 12D. An edge portion 12B is disposed on the lower surface side of the annular rib 25C, and is configured so as not to interfere with the diaphragm 12 like the radiation rib 25B. Since the annular rib 25C is arranged slightly outside the additional plate 12D bonded to the upper surface side of the diaphragm 12 as shown by the broken line in FIG. 4, it does not interfere with the additional plate 12D. Further, the annular rib 25C is formed in an annular shape, and the strength of the central portion of the cover body 24A having no beam can be ensured.

  As described above in detail, the electroacoustic transducer 10 according to the present embodiment is configured to be mounted on an external device. However, the cover member 24 is formed of a resin, and the diaphragm 12 of the cover member 24 is further formed. Since the rib 25 is formed on the surface facing the edge portion 12B, the following effects can be obtained.

  That is, by forming the cover member 24 from a resin, when the cover member 24 is disposed on a mobile phone or the like, it is possible to prevent adverse effects on the antenna, which is another electronic component, and further, the rib 25 is formed to increase the strength of the cover member 24. By improving, the resin cover member 24 can be formed thin.

  As described above, according to the present invention, in an electroacoustic transducer configured to be mounted on an external device, a product that does not adversely affect other electronic components and has sufficient durability is provided. be able to.

  Further, since the edge portion 12B of the diaphragm 12 is curved so as to protrude toward the other end side, that is, the lower surface side of the diaphragm 12, the radiating rib 25B, the annular rib 25C, and the like are formed on the upper surface side of the edge portion 12B. Even if the rib 25 is formed, the vertical movement accompanying the ringing of the diaphragm 12 can reduce the possibility that the edge portion 12B interferes with the rib 25, and stable acoustic vibration can be obtained.

  Furthermore, since the rib 25 is formed on the outer peripheral diaphragm 12 on which the additional plate 12D is placed, the additional plate 12D protrudes from the diaphragm 12 to the cover member 24 side. Due to the up-and-down movement accompanying the ringing, there is no fear that the additional plate 12D contacts the rib 25, and stable acoustic vibration can be obtained.

  Further, since the rib 25 has an annular ring rib 25C so as to surround the outer peripheral portion of the additional plate 12D, the rib 25 is particularly free in the vicinity of the center of the cover member 24 on the upper surface side of the additional plate 12D where the rib 25 is not formed. The strength around the sound hole 24B can be improved.

  Furthermore, it is also possible to apply the cover member 24 of the present invention to the electroacoustic transducer 10 formed in a substantially square shape. At that time, by configuring the radiating rib 25B to extend to the annular rib 25C from the side center and corners of the cover member 24, the strength of the cover member 24 can be efficiently increased only by forming a small number of radiating ribs 25B. Can be improved.

  Moreover, in the said embodiment, although demonstrated as what the electroacoustic transducer 10 is an electrodynamic type speaker, also when it is other electroacoustic transducers (for example, receiver etc.), it is the same as that of the said embodiment. By adopting the configuration, it is possible to obtain the same effects as the above-described embodiment.

  In addition, the numerical value shown as a specification in the said embodiment is only an example, and of course, you may set these to a different value suitably.

The disassembled perspective view which shows the electroacoustic transducer 10 which concerns on one Embodiment of this invention. Sectional drawing of the electroacoustic transducer 10 which concerns on one Embodiment of this invention. The perspective view which looked at the cover member 24 from the lower surface side The disassembled perspective view which shows a part of electroacoustic transducer 10 which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electroacoustic transducer 12 Diaphragm 12A Outer peripheral plane part 12B Edge part 12C Central plane part 12D Additional plate 14 Voice coil 16 Magnetic circuit unit 18 Terminal plate 20 Frame 20A Frame bottom face part 20B Upper flange part 20C Lower flange part 20D Circular opening Part 20E Lower part 20F Upper part 20G Middle part 20H Notch part 22 External connection terminal 24 Cover member 24A Cover body 24B Sound emitting hole 24C Case fitting part 24D Outer peripheral surface 25 Rib 25A Outer peripheral rib 25B Radiating rib 25C Annular rib 28 Base 28A Through hole 30 Magnet 32 York

Claims (6)

A plane part in the center, and a diaphragm having an edge part around the plane part;
An additional plate placed on a flat surface at one end of the diaphragm;
One end is fixed to the other end of the diaphragm, and a voice coil configured by winding a conducting wire;
A magnetic circuit unit formed with a magnetic gap for accommodating the other end of the voice coil;
A housing for protecting the magnetic circuit unit;
A cover member attached to the housing and covering a part of the magnetic circuit unit;
In a speaker with
The cover member is formed of resin,
An electroacoustic transducer, wherein a beam portion is formed on at least a surface of the cover member facing the edge portion of the diaphragm.
The electroacoustic transducer according to claim 1, wherein the edge portion is curved so as to protrude toward the other end portion of the diaphragm.
The electroacoustic transducer according to claim 1, wherein the beam portion is formed on an upper surface side of the diaphragm on the outer periphery of the additional plate mounting portion.
The electroacoustic transducer according to any one of claims 1 to 3, wherein the beam portion includes an annular ring rib that surrounds at least an outer peripheral portion of the additional plate.
The cover member is formed in a substantially square shape,
The electroacoustic transducer according to claim 4, wherein the beam portion includes a radiation rib extending from at least a center and a corner portion of the cover member to the annular rib.
The electroacoustic transducer according to claim 1, wherein the cover member is made of a resin having a thickness of 0.2 mm or less.

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