JP2013157735A - Speaker, video acoustic apparatus and portable information processing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker using a small size and wide band magnetic fluid having a reproduction band satisfying a long and stable operation and reproducing characteristics, and to establish a technique to manufacture a stable speaker device.SOLUTION: The speaker device includes: a magnetic circuit having a magnetic gap; a voice coil at least a part of which is disposed in the magnetic gap; a diaphragm to which the voice coil is fixed; plural supports supporting the diaphragm; and a magnetic fluid disposed on the inner periphery or the outer periphery of the voice coil. The shape of the diaphragm of the voice coil fixing portion has a flat portion in a disposing direction of the magnetic fluid, and the side where the magnetic fluid is not disposed is formed protruding to the magnetic circuit side from the fixing part.

Description

  The present invention relates to a speaker, an audiovisual apparatus including the speaker, and a portable information processing apparatus including the speaker. More specifically, the present invention relates to a small speaker capable of wide-band reproduction, and an audiovisual apparatus including the speaker. And a portable information processing apparatus including the speaker, a moving unit, and an inner phone.

  In recent years, miniaturization and high functionality of audiovisual apparatuses, so-called AV equipment, are rapidly progressing. This is particularly noticeable in mobile phones, smartphones, tablet PC (personal computer) terminals, etc., but since miniaturization and high functionality are progressing simultaneously, devices to be mounted are required to be smaller and thinner. The speaker mounted on each device is no exception, and it is required to be small and thin like other devices. However, downsizing of the speaker leads to deterioration in reproduction capability, particularly reproduction frequency band and reproduction efficiency, and thus there has been a limit in miniaturization and reproduction capability in the conventional technology.

  Thus, as a conventional technique, there has been a speaker in which a magnetic fluid is arranged in a magnetic circuit to improve a speaker reproduction band (see, for example, Patent Document 1). FIG. 9 shows a conventional speaker described in Patent Document 1 described above.

  In the speaker shown in FIG. 9, the voice coil 106 is disposed in the magnetic circuit 108 and the diaphragm 103 is driven. The magnetic fluid 107 is disposed between the outer periphery of the plate 102 of the magnetic circuit 108 and the inner periphery of the voice coil 106, and the sound generated from the front surface is separated by separating the space on the front surface of the diaphragm 103 from the space on the rear surface. In addition to preventing cancellation of sound generated from the back surface, rolling vibration of the diaphragm 103 is prevented, and Joule heat generated in the voice coil 106 is released to the magnetic circuit 108 portion. Further, by supporting the diaphragm 103 with a plurality of edge portions 104a, 104b, 104c, and 104d together with the magnetic fluid 107, a support system that works on the diaphragm compared to the case where the entire outer periphery of the diaphragm 103 is configured with edges. Compliance has been increased, and low frequency reproduction is possible even with a small aperture.

  As shown in FIG. 9, the shape of the diaphragm 103 at the joint with the voice coil 106 is concave with respect to the voice coil 106. This concave shape secures a sufficient bonding area with the voice coil 106, ensures adhesive strength, and when the diaphragm 103 and the voice coil 106 are joined with an adhesive, an adhesive is applied to the concave portion. Thus, it has two roles for preventing the adhesive from flowing out of the bonded portion.

Japanese Patent Application No. 2009-542463

  If the speaker configured as in Patent Document 1 is left for a while, the amount of magnetic fluid 107 disposed on the inner periphery of the voice coil 106 and the outer periphery of the plate 102 is significantly reduced, so that the front and rear surfaces of the diaphragm 103 are reduced. There is a problem in that the spaces are connected, the sounds on the front and back sides cancel each other, and the reproduction characteristics deteriorate.

  When the cause of the decrease in the magnetic fluid 107 was analyzed, the magnetic fluid 107 moved along the surface of the voice coil 106 and stayed in the gap between the voice coil 106 in the concave portion of the diaphragm 103 and the concave portion of the diaphragm 103. Since the voice coil 106 is generally formed by winding a thin conductor wire, there are fine irregularities on the surface. It is considered that the magnetic fluid 107 is gradually transferred due to the capillary phenomenon caused by the fine irregularities on the surface of the voice coil 106. As time elapses, the magnetic fluid 107 moves in the gap between the voice coil 106 and the concave portion of the diaphragm 103, and the magnetic fluid disposed in the magnetic gap between the inner periphery of the voice coil 106 and the outer periphery of the plate 102. The amount of 107 decreases. When the volume of the gap between the voice coil 106 and the diaphragm 103 is large, the magnetic fluid 107 in the magnetic gap decreases significantly as the space before and after the diaphragm 103 is connected.

  Patent Document 1 also discloses an example in which the shape of the diaphragm 103 at the joint portion of the voice coil 106 is flat as shown in FIG. Unlike FIG. 9, since the diaphragm 103 does not have a recess, there is no space for the magnetic fluid 107 to accumulate, and the movement of the magnetic fluid 107 can be suppressed. However, since there is no concave portion in the diaphragm 103, the adhesive cannot stay when the adhesive is applied for joining the voice coil 106 and the diaphragm 103, and flows out. The adhesive which has flowed out and hardened breaks the weight balance of the diaphragm 103 and causes asymmetric vibration, contact between the diaphragm 103 or the voice coil 106 and the magnetic circuit 108, and inhibits stable operation. In addition, since the bonding area between the diaphragm 103 and the voice coil 106 is only on the upper surface of the voice coil 106, the bonding area cannot be secured sufficiently, so that a sufficient bonding strength cannot be obtained, and the operation such as detachment of the operating voice coil 106 is performed. It causes a defect.

  The present invention solves the conventional problems, and in the above-described speaker that enables reproduction in a low frequency range even with a small diameter using a magnetic fluid, and AV equipment equipped with the speaker, stable reproduction characteristics for a long period of time. The purpose is to provide.

  In order to solve the conventional problems, in a first aspect of the speaker device of the present invention, a magnetic circuit having a magnetic gap, a voice coil disposed in the magnetic gap, and either the inside or the outside of the voice coil. In the speaker device having the magnetic fluid disposed on the diaphragm, the diaphragm on which the voice coil is secured, and a plurality of edges that support the diaphragm, the side on which the magnetic fluid is disposed on the voice coil securing portion of the diaphragm Has a flat portion, and the outside of the diaphragm has a convex shape on the magnetic circuit side.

  With this configuration, even if the magnetic fluid moves to the diaphragm side along the voice coil surface due to capillary action, the diaphragm shape of the voice coil fixing part on the magnetic fluid arrangement side is flat, so that the magnetic fluid Since there is almost no staying space, it is possible to prevent the magnetic fluid disposed between the magnetic gaps from decreasing. At the same time, the diaphragm shape of the voice coil fixing part on the side where the magnetic fluid is not disposed is formed in a convex shape on the magnetic circuit side, so that the adhesive is prevented from flowing out when applying the adhesive for fixing the voice coil. In addition to preventing unnecessary vibration and contact, sufficient adhesion strength can be ensured by the adhesion area secured by the convex shape.

  In the second aspect of the speaker device of the present invention, the magnetic circuit is composed of a yoke, a plate, and a magnet, and the magnetic fluid is disposed on the plate side of the voice coil disposed between the magnetic gaps formed between the yoke and the plate. It may be a feature that is arranged.

  Thereby, since magnetic fluid is arranged at the plate side, magnetic fluid is located more stably.

  In the third aspect of the speaker device of the present invention, the magnetic fluid is disposed inside the voice coil, has a flat portion inside the voice coil fixing portion of the diaphragm, and outside the voice coil fixing portion of the diaphragm. A flat portion may be formed at a portion corresponding to the lead-out portion of the voice coil that is formed so as to protrude toward the magnetic circuit side.

  As a result, a flat part is formed in a part corresponding to the lead-out part of the voice coil at a part of the convex shape outside the voice coil of the diaphragm. Since it is not necessary to reduce the bending radius of the voice coil, disconnection can be prevented. Further, abnormal noise due to contact between the diaphragm and the voice coil can be prevented.

  In the fourth aspect of the speaker device of the present invention, the voice coil has a circular shape, a track shape, an ellipse, or a shape in which a plurality of linear portions are joined by a continuous curve. May be a feature.

  Thereby, the shape of the voice coil can be selected from any one of a circular shape, a track shape, an ellipse, and a shape in which a plurality of linear portions are joined by a continuous curve. More specifically, by setting the curvature radius of the curve to 1 mm or more, it is possible to prevent the magnetic fluid from creeping up due to the shape of the voice coil. Thereby, a suitable shape can be selected according to the shape of the apparatus using a speaker.

  In the fifth aspect of the speaker device of the present invention, the height of the inner side of the voice coil of the magnetic circuit and the height of the outer side of the voice coil of the magnetic circuit are lowered on the side where the convex portion of the diaphragm is formed. May be a feature.

  Thereby, by forming the height of the plate lower than the height of the yoke, it is possible to more effectively prevent contact between the magnetic circuit and the diaphragm when the diaphragm has a large amplitude. This is advantageous in reducing the thickness of the speaker while maintaining the reproduction sound pressure performance.

  In the speaker device of the present invention, it is possible to prevent the magnetic fluid disposed between the magnetic gaps from decreasing. Therefore, a speaker capable of reproducing in a low frequency region even with a small diameter using a magnetic fluid and an AV device equipped with the speaker can provide stable reproduction characteristics for a long period of time.

Cross-sectional view of the structure of the speaker according to Embodiment 1 of the present invention Structure sectional enlarged view of the speaker according to Embodiment 1 of the present invention. Cross-sectional view of the structure of the speaker according to Embodiment 1 of the present invention Cross-sectional view of the structure of the speaker according to Embodiment 2 of the present invention Cross-sectional view of the structure of a speaker according to Embodiment 3 of the present invention Mobile information terminal apparatus according to Embodiment 4 of the present invention Image display apparatus according to embodiment 5 of the present invention Car-mounted speaker mounting diagram in Embodiment 6 of the present invention Cross-sectional view of the structure of the inner phone according to the seventh embodiment of the present invention Cross-sectional view of a conventional speaker structure Cross-sectional view of a conventional speaker structure

  Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1)
FIG. 1 is a structural cross-sectional view of the speaker device according to the first embodiment of the present invention. In FIG. 1, 10 is a yoke, 11 is a magnet, 12 is a plate, 13 is a diaphragm, 14a to d are edges, 15 is a frame, 16 is a voice coil, and 17 is a magnetic fluid. The yoke 10, the magnet 11, and the plate 12 constitute an internal magnetic circuit, and a magnetic gap is formed between the yoke 10 and the plate 12. A voice coil 16 is disposed in the magnetic gap. The voice coil 16 is fixed to the diaphragm 13, and the diaphragm 13 is supported by edges 14a to 14d. A magnetic fluid 17 is disposed between the voice coil 16 and the plate 12 and is held by a magnetic field in the magnetic gap. Reference numerals 16a and 16b denote lead lines for the voice coil 16, which are fixed on the frame 15 or the magnetic circuit. In FIG. 1, the lead wire is described above the diaphragm 13, but may be between the diaphragm 13 and the frame 15. Alternatively, an electrode may be provided on a part of the frame 15 or on the back side of the magnetic circuit and wired there.

  The shape of the voice coil 16 fixing portion of the diaphragm 13 has a flat portion on the inner diameter side, and the outer diameter side is formed in a convex shape toward the magnetic circuit.

  The operation of this speaker device will be described below. When a sound signal is applied to the voice coil 16, a force proportional to the magnetic flux density in the magnetic gap and the flowing current is generated in the voice coil 16 in accordance with the Fleming left-hand rule. As a result, the diaphragm 13 vibrates and reproduces sound. Unlike general electrodynamic loudspeakers, the edges 14a to 14d are a plurality of divided edges, and thus have no role in separating the space before and after the diaphragm 13. However, since the magnetic fluid 17 is filled inside the voice coil 16, the space inside the voice coil 16 and the space in front of the diaphragm 13 are separated. For this reason, the sound reproduced from the front surface of the diaphragm 13 is not canceled out by the antiphase sound generated from the rear surface of the diaphragm 13 inside the voice coil 16.

  At the same time, since the outside of the diaphragm 13 is convexly formed on the magnetic circuit side, the adhesive is vibrated by applying the adhesive along the inside of the convex portion when the diaphragm 13 and the voice coil 16 are bonded. It is possible to prevent the voice 13 from flowing out of the bonding position of the voice coil 16 on the plate 13. Further, since the adhesive is applied along the convex portion, the protrusion to the inside can be minimized. For this reason, it can prevent that the weight balance of the diaphragm 13 collapse | crumbles and the vibration distribution is disturb | confused by the protrusion of an adhesive agent. Further, since the convex portion also contacts the side surface of the voice coil 16, the bonding strength between the diaphragm 13 and the voice coil 16 is increased.

  In addition, it is desirable that the upper surface or the side surface of the voice coil 16 is bonded to the entire circumference at the bonding portion between the voice coil 16 and the diaphragm 13. If there is a gap that passes from the inner peripheral side of the voice coil 16 to the outer peripheral side in the adhesive part, the magnetic fluid 17 flows to the outer peripheral part of the voice coil 16 from the inner peripheral side of the voice coil 16 to the outer peripheral part of the voice coil 16. This is because the magnetic fluid 17 may stay in

  Since the inside of the voice coil 16 of the diaphragm 13 is a flat portion in FIG. 1, even if the magnetic fluid 17 moves on the inner diameter side surface of the voice coil 16 to the diaphragm 13 side by capillary action, the magnetic fluid 17 Therefore, the magnetic fluid 17 in the magnetic gap is not greatly reduced. For this reason, the role which separates diaphragm 13 front and back is not lost. Although it has been described that the inside of the voice coil 16 of the diaphragm 13 has a flat portion, the diaphragm may be bent on the side opposite to the magnetic circuit with the adhesive surface of the voice coil 13 as a reference.

  The width of the flat portion is designed in consideration of the dimensional tolerance of the voice coil 16 in the radial direction and the wettability between the magnetic fluid 17 and the diaphragm 13. Note that the inner peripheral radius of the flat portion may be designed to be larger than the outer diameter of the plate 12. In order to ensure a high frequency side reproduction band, the inner side of the inner periphery of the flat portion is projected on the opposite side of the magnetic circuit in order to ensure a certain degree of rigidity of the diaphragm 13. In such a case, the distance between the diaphragm 13 and the magnetic circuit can be increased, which is advantageous for thinning. If the width of the flat portion is too large, plane resonance occurs in the flat portion of the diaphragm 13, and therefore it is desirable to set the width of the substantially flat shape to an appropriate value in consideration of the reproduction band.

  If the shape of the diaphragm 13 is convex over the entire outer periphery of the voice coil 16, the voice coil lead wires 16a and 16b may interfere with the outer periphery of the voice coil 16 of the diaphragm 13 during manufacturing and assembly. In this case, it is necessary to bend along the convex portion of the diaphragm 13 while bending the lead portion of the voice coil 16 with a short radius of curvature. If it is not bent with a sufficient radius of curvature, the voice coil 16 is liable to float from the diaphragm 13 due to the rigidity of the voice coil 16. In order to solve such a problem, the shape of the diaphragm may be changed only in the drawing portion of the voice coil 16 as shown in FIG. In the upper right of FIG. 1b, a diagram of the diaphragm 13 and the lead wire 16a as viewed from the cross-sectional direction of the lead wire 16a is shown. As described above, the outside of the outer peripheral portion of the diaphragm 13 has a structure in which the lead wire 16 a can be easily along the diaphragm 13. In addition, in the outer peripheral portion of the diaphragm 13, only the lead-out portion of the voice coil 16 is not convex but flat as shown in FIG. There are advantages such that the voice coil 16 is not tilted and fixed to the diaphragm 13 during manufacturing, and the voice coil 16 can be easily positioned in the rotational direction. Furthermore, the diaphragm 13 and the drawing portion of the voice coil 16 are less likely to come into contact with each other during operation, and an advantage that noise due to contact can be further prevented can be obtained.

  Although FIG. 1a shows an embodiment of a circular magnetic circuit and a circular voice coil 16, the present invention may be applied to a rectangular speaker as shown in the sectional view of the structure in FIG. In FIG. 2, the shape of the voice coil 16 is a shape in which two sets of parallel line segments are connected to each other by a curve, and the magnetic circuit has a shape corresponding to the voice coil 16. Reference numerals 14a and 14b denote edges that support the diaphragm and are arranged at both ends of the rectangular speaker in the longitudinal direction. Depending on the aspect ratio of the rectangle and the rectangle, the rectangular speaker can be arranged in a narrow part of the device casing, or can be arranged in a place with a small depth.

  In addition, the shape of the voice coil 16 may be a track shape in which a pair of parallel line segments are connected by a curved line or an elliptical shape. The radius of the curve used for each is preferably 1 mm or more in order to prevent the magnetic fluid from creeping up at the 16 corners of the voice coil.

(Embodiment 2)
FIG. 3 is a structural cross-sectional view of the speaker device according to the second embodiment of the present invention. In FIG. 3, the configuration of the magnetic circuit and the names of members such as the diaphragm 13 are the same as those in the first embodiment, and are omitted. The difference is that the magnetic fluid 17 is disposed between the outside of the voice coil 16 and the inside of the yoke 10, and accordingly, the flat part of the diaphragm 13 is outside the voice coil 16, and the convex part is the yoke 10. Located inside.

  The width of the flat portion is determined in consideration of the dimensional tolerance of the voice coil 16 and the contact angle between the magnetic fluid 17 and the diaphragm 13 as in the first embodiment.

  Since the operation of the speaker is the same as that of the first embodiment, a description thereof will be omitted.

  In FIG. 3, since the outside of the voice coil 16 of the diaphragm 13 is a flat portion, even if the magnetic fluid 17 moves on the outer diameter side surface of the voice coil 16 to the diaphragm 13 side by capillary action, the magnetic fluid Since there is no portion where 17 stays, the magnetic fluid 17 in the magnetic gap is not greatly reduced. For this reason, the role which separates diaphragm 13 front and back is not lost. Although it has been described that the outer side of the voice coil 16 of the diaphragm 13 has a flat portion, the diaphragm 13 may be bent on the opposite side of the magnetic circuit with the adhesive surface of the voice coil 16 as a reference.

  The width of the flat portion is designed in consideration of the dimensional tolerance of the voice coil 16 in the radial direction and the wettability between the magnetic fluid 17 and the diaphragm 13. In addition, you may design the outer periphery radius of a flat part smaller than the internal diameter of the part which opposes the plate 12 of the yoke 10. FIG. Outside the outer periphery of the flat portion, an edge is formed that is convex on the opposite side of the magnetic circuit. In such a case, the distance between the diaphragm 13 and the magnetic circuit can be increased, which is advantageous for thinning. If the width of the flat portion is too large, plane resonance occurs in the flat portion of the diaphragm 13, and therefore it is desirable to set the width of the flat portion to an appropriate value.

  At the same time, since the inner side of the diaphragm 13 is convexly formed on the magnetic circuit side, the adhesive is vibrated by applying an adhesive along the inner side of the convex part when the diaphragm 13 and the voice coil 16 are bonded. It can be prevented that the voice coil 16 of the plate 13 flows out from the bonding position. Further, since the adhesive is applied along the convex portion, the protrusion to the outside can be minimized. For this reason, it can prevent that the weight balance of the diaphragm 13 collapse | crumbles and the vibration distribution is disturb | confused by the protrusion of an adhesive agent. Further, since the convex portion also contacts the side surface of the voice coil 16, the bonding strength between the diaphragm 13 and the voice coil 16 is increased.

(Embodiment 3)
FIG. 4 is a structural cross-sectional view of the speaker device according to the third embodiment of the present invention. In FIG. 4, the names of the respective members are the same as those in the first embodiment, and will be omitted. The present embodiment differs from the first and second embodiments in that the magnet 11 is located outside the magnetic gap and has a so-called external magnetic type structure. The magnetic fluid 17 is disposed between the outside of the voice coil 16 and the inside of the yoke 10 as in the second embodiment. The flat part of the diaphragm is located outside the voice coil 16 and the convex part is located inside the yoke 10.

  Since the operation of the speaker is the same as that of the first embodiment, a description thereof will be omitted.

  In FIG. 4, since the outer side of the voice coil 16 of the diaphragm 13 is a flat portion, even if the magnetic fluid 17 moves on the outer diameter side surface of the voice coil 16 to the diaphragm 13 side by capillary action, the magnetic fluid Since there is no portion where 17 stays, the magnetic fluid 17 in the magnetic gap is not greatly reduced. For this reason, the role which separates diaphragm 13 front and back is not lost. In addition, although it described that the outer side from the voice coil 16 of the diaphragm 13 has a flat part, the diaphragm 13 may be bent on the opposite side to a magnetic circuit on the basis of the adhesive surface of the diaphragm 13 and the voice coil 16. .

  Since the width of the flat portion is the same as that of the second embodiment, the description is omitted.

  At the same time, since the inner side of the diaphragm 13 is convexly formed on the magnetic circuit side, the adhesive is vibrated by applying an adhesive along the inner side of the convex part when the diaphragm 13 and the voice coil 16 are bonded. It can be prevented that the voice coil 16 of the plate 13 flows out from the bonding position. Further, since the adhesive is applied along the convex portion, the protrusion to the outside can be minimized. For this reason, it can prevent that the weight balance of the diaphragm 13 collapse | crumbles and the vibration distribution is disturb | confused by the protrusion of an adhesive agent. Further, since the convex portion also contacts the side surface of the voice coil 16, the bonding strength between the diaphragm 13 and the voice coil 16 is increased.

(Embodiment 4)
FIG. 5 shows a mobile information terminal apparatus according to Embodiment 4 of the present invention. In FIG. 5, 201 is a mobile information terminal device, 202 is a screen, and 1 is a speaker device selected from those shown in the first to third embodiments. The speaker device 1 may be attached to the mobile information terminal device 201 together with a sealed cabinet or a bass reflex cabinet. Further, the cabinet may be attached to the mobile information terminal device 201 as an open type without being attached. In FIG. 5, the speaker devices 1 are arranged at three locations, but any number of speaker devices may be used as long as the number is one or more. If there is one, it will be monaural, but if it is two, it can be used as a device for sound field control or HRTF if two or more are used.

  By mounting the speaker device 1 on a device having a limited mounting volume, such as the mobile information terminal device 201, it is possible to stably perform wide band reproduction even with a limited volume. Regarding the mounting direction at the time of mounting, the diaphragm 13 may be directed to the sound hole side or the magnetic circuit may be directed to the sound hole side with respect to the sound hole provided in the housing.

(Embodiment 5)
FIG. 6 shows an image display apparatus according to the fifth embodiment of the present invention. More specifically, it is a PC or a thin TV. In FIG. 6, 203 is an image display device, 202 is a screen, and 1 is a speaker device selected from those shown in the first to third embodiments. The speaker device 1 may be attached to the image display device 203 together with a sealed cabinet or a bass reflex cabinet. Further, the cabinet may be attached to the image display device 203 as it is without being attached. In FIG. 6, the speaker devices 1 are arranged at a total of 16 locations, but any number of speaker devices may be used as long as the number is one or more. If one unit is monaural, two units are stereo, and if two or more units are used (for example, arranged as a line array), it can also be used as a device for sound field control or HRTF.

  By mounting the speaker device 1 on a device having a limited mounting volume, such as the image display device 203, wide-band reproduction can be stably performed even with a limited volume. Regarding the mounting direction at the time of mounting, the diaphragm 13 may be directed to the sound hole side or the magnetic circuit may be directed to the sound hole side with respect to the sound hole provided in the housing.

(Embodiment 6)
FIG. 7 is a mounting diagram of the vehicle-mounted speaker according to the sixth embodiment of the present invention. In FIG. 7, reference numeral 204 denotes an automobile door, and reference numeral 1 denotes a speaker device selected from those shown in the first to third embodiments. The speaker device 1 may be attached to the door 204 of the automobile together with the sealed cabinet or the bass reflex cabinet. Further, the cabinet may be attached as it is to the automobile door 204 as an open type without being attached. In FIG. 7, the speaker devices 1 are arranged at three locations, but any number of speaker devices may be used as long as the number is one or more. 7 shows an example in which the vehicle is attached to the door 204 of the automobile, it may be attached to any position of the automobile such as a dashboard, pillar, seat, headrest, or ceiling of the automobile. In addition to automobiles, they may be attached to various moving means such as trains, monorails, linear motors, airplanes, and ships.

  Conventionally, large-scale speakers have been required for wide-band reproduction, particularly for reproducing low-pitched sounds. Since the speaker using the magnetic fluid 17 of the present application can realize a speaker that can reproduce low-frequency sound even if it is small, it can realize the same acoustic characteristics as a conventional speaker with a smaller or lighter speaker. As a result, the entire moving means is reduced in size and weight, and the comfort can be improved by increasing the living space, or the fuel efficiency can be improved by reducing the size and weight of the vehicle body.

  Regarding the mounting direction at the time of mounting, the diaphragm 13 may be directed to the sound hole side or the magnetic circuit may be directed to the sound hole side with respect to the sound hole provided in the housing.

(Embodiment 7)
FIG. 8 is a mounting diagram of the inner earphone according to the seventh embodiment of the present invention. In FIG. 8, 205 is an inner earphone, 206 is an inner earphone cord, and 207 is an eartip. Reference numeral 1 denotes a speaker device selected from those shown in the first to third embodiments.

  Conventionally, since a speaker (receiver) used for the inner earphone 205 has a small aperture, it has been difficult to reproduce a rich bass with a high minimum resonance frequency. By mounting the speaker device 1 of the present invention on the inner earphone 205 this time, it is possible to provide the inner earphone 205 that can reproduce richer bass than ever before. Regarding the mounting direction at the time of mounting, the diaphragm 13 may be directed to the sound hole side or the magnetic circuit may be directed to the sound hole side with respect to the sound hole provided in the housing.

  The ear tip 207 in FIG. 8 is a sealed ear tip 207. However, the ear tip 207 has a vent hole in the umbrella portion of the ear tip 207, and an open type in which outside air can flow from the inside of the ear hole through the vent hole of the ear tip 207. Ear tips may be used. If an open-type ear tip is used, the ear hole can be prevented from becoming stuffy.

  Although the seventh embodiment is a description related to the inner earphone 205, it may be applied to a headset, a headphone, or a hearing aid.

  The speaker device according to the present invention is capable of reproducing a wide band even though it is small, and can operate stably, so that it is useful alone as a small high-quality sound speaker. Moreover, in each apparatus which mounts a speaker, it is useful as a small high quality sound quality device.

DESCRIPTION OF SYMBOLS 1 Speaker apparatus in this invention 10 Yoke 11 Magnet 12 Plate 13 Diaphragm 14a, 14b, 14c, 14d Edge 15 Frame 16 Voice coil 16a, 16b Lead wire of voice coil 17 Magnetic fluid 100 Yoke 101 Magnet 102 Plate 103 Diaphragm 104a, 104b, 104c, 104d Edge 105 Frame 106 Voice coil 107 Magnetic fluid 108 Magnetic circuit 201 Mobile information terminal device 202 Screen 203 Image display device 204 Automotive door 205 Inner earphone 206 Inner earphone code 207 Ear tip

Claims (6)

A speaker device,
A magnetic circuit having a magnetic gap;
A voice coil at least partially disposed in the magnetic gap;
A diaphragm to which the voice coil is fixed;
A plurality of supports for supporting the diaphragm;
Consists of a magnetic fluid disposed on either the inner periphery or the outer periphery of the voice coil,
The shape of the diaphragm of the voice coil fixing part is
It has a flat part in the arrangement side direction of the magnetic fluid,
2. The speaker device according to claim 1, wherein the side on which the magnetic fluid is not disposed is formed so as to protrude toward the magnetic circuit side from the fixing portion.   The magnetic circuit is composed of a yoke, a plate, and a magnet, and the magnetic fluid is arranged on the plate side of the voice coil arranged between magnetic gaps formed between the yoke and the plate. The speaker device according to claim 1. The magnetic fluid is disposed inside the voice coil;
A flat portion inside the voice coil fixing portion of the diaphragm,
The outer side of the voice coil fixing portion of the diaphragm is formed to be convex toward the magnetic circuit side, and a flat portion is formed at a portion corresponding to the lead portion of the voice coil. The speaker device according to 1. The shape of the voice coil is
2. The speaker device according to claim 1, wherein the speaker device has any one of a circular shape, a track shape, an ellipse, and a shape in which a plurality of linear portions are joined by a continuous curve. The inner height of the voice coil of the magnetic circuit;
Of the height outside the voice coil of the magnetic circuit,
The speaker device according to claim 1, wherein a side on which the convex portion of the diaphragm is formed is lowered. The speaker device according to any one of claims 1 to 5,
AV devices such as video display devices and audio devices, mobile information devices such as mobile phones, smartphones, and tablet PCs, home appliances, and automobiles.

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