JP3801808B2 - earphone - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an earphone for music reproduction or communication, and more particularly to an improvement of an inner-type earphone used as a mini headphone, for example, in an ear canal cavity.
[0002]
[Prior art]
Conventionally, a configuration as shown in FIG. 10 is known as this type of earphone.
That is, a cylindrical recess 3 is formed in the substantially central portion of the disc-shaped support plate 1, and a cylindrical magnet portion 5 and a disc-shaped pole piece 7 are coaxially stacked in the recess 3. The vibration film 9 is fixed to the upright portion 1 a provided on the peripheral edge of the support plate 1 to cover the concave portion 3 and the pole piece 7, and the voice coil 11 is interposed between the magnet portion 5 and the pole piece 7 and the inner wall of the concave portion 3. Is supported by the diaphragm 9 while the circuit board 13 is loosely inserted, and the circuit board 13 is fixed to the outer bottom portion of the recess 3, while the lead wire 11 a extending from the voice coil 11 is opposed to the outer periphery of the upright portion 1 a of the support plate 1 ( The lead wire 11a is connected to the circuit board 13 through the flat part 1b formed on the outer periphery of the concave part 3 in the support plate 1 while covering the concave part 3 and the circuit board 13 Support plate with back case 15 It is brought into contact with the peripheral portion, in which a flat front case 19 having a plurality of sound holes 17, and fixed over the distal end of the outer periphery and the back case 15 of the support plate 1 so as to cover the vibrating membrane 9.
[0003]
Moreover, the support plate 1 has a plurality of vent holes 21 communicating the vibration membrane 9 side as the front side and the back case 15 side as the back side so as to obtain a wide frequency characteristic while maintaining the low frequency characteristics of the earphone. The back case 15 used was a cup-shaped bulge that was curved and bulged in a semi-elliptical manner so that an acoustic space was formed on the back side of these vent holes 21 while penetrating through the flat portion 1b.
[0004]
Reference numeral 23 in FIG. 10 is an adhesive that fixes the lead wire 11a of the voice coil 11 led out from the vibrating membrane 9 to the circuit board 13 to the flat portion 1b of the support plate 1 to prevent disconnection or the like. In FIG. 2, the adhesive 23 is adhered to a portion where the vent 21 is not blocked.
[0005]
Further, the air holes are provided so that flux and solder scraps scattered when soldering the lead wire 11a of the voice coil 11 to the circuit board 13 are not directly attached to the vibrating membrane 9 through the air holes 21 to deteriorate the performance. 21 is closed with a breathable net (not shown).
The circuit board 13 is a relay terminal plate for connecting a cable (not shown) connecting the electronic device such as a recording / playback device and a communication device to the lead wire 11a of the voice coil 11.
[0006]
Such an earphone has an outer shape in which the front case 19 bulges slightly toward the front side at the center portion, while the back case 15 greatly bulges in a semi-elliptical pearl shape toward the back side. As shown in FIG. 12, the front case 19 is fitted in the ear canal cavity 25d formed so as to be surrounded by the antipod 25a, the antipod 25b, and the tragus 25c in the human ear 25 with the front case 19 facing the external auditory canal 25e as shown in FIG. In other words, the back case 15 is mainly held by the antipod 25b and the tragus 25c. In FIG. 11, reference numeral 25f denotes an ear ring.
[0007]
[Problems to be solved by the invention]
However, since the back case 15 of the conventional earphone described above is also curved in the shape of a semi-elliptical bead near the open tip, when it is fitted into the ear canal cavity 25d, the main earphone 25b and the tragus are mainly used. While the back case 15 is supported by 25c, depending on the user, there is a difficulty in feeling the oppressive feeling and the pain by pressing the antipod 25b and the tragus 25c against the back case 15 depending on the user.
[0008]
In addition, since the curved portion of the back case 15 tends to always press the antipod 25b and the tragus 25c, the earphone is easily detached from the ear 25.
Furthermore, in the above-described earphone, the vent hole 21 is provided in the flat portion 1b formed on the outer periphery of the concave portion 3 in the support plate 1. Therefore, when the lead wire 11a of the voice coil 11 is soldered to the circuit board 13. It is necessary to close the vent hole 21 with a breathable net (not shown) so that flux and solder scraps scattered on the film do not adhere to the vibrating membrane 9 through the vent hole 21, which increases the number of parts and manufacturing man-hours and reduces costs. It was an obstacle.
[0009]
On the other hand, in the human ear 25, the external auditory canal 25e is generally inclined from the ear canal cavity 25d to the inside of the human head 27 as shown in FIG. Since it extends upward, the central axis X of the speaker unit formed by the magnet unit 5, the vibration film 9, the voice coil 11, etc. in the earphone is shifted in both angle and position with respect to the central axis Y of the ear canal 25 e, and the speaker unit The (center axis X) is opposed to the center axis Y with a large inclination, so that the sound from the vibration film 9 is not easily radiated along the center axis Y, and “sensitivity is lowered” and “high sound is attenuated. There is also a difficulty that the acoustic characteristics are liable to be lowered, such as “the bass is attenuated”.
[0010]
The present invention has been made to solve such a conventional problem, and an object of the present invention is to provide an earphone that improves the comfort of wearing on the ear and reduces the dropout from the ear.
It is another object of the present invention to provide an earphone that can easily reduce costs while reducing the number of components and manufacturing steps while ensuring good acoustic characteristics.
[0011]
[Means for Solving the Problems]
In order to solve such a problem, the present invention provides a magnet part that forms a speaker part of an earphone, a support plate that supports the magnet part on one side and has an annular flat part formed around the magnet part, and a voice A vibrating membrane that has a coil and is supported by the supporting plate so as to cover the magnet portion on the front side of the magnet portion with a gap therebetween, and a supporting plate with the side on which the vibrating membrane is not disposed as the back side to a rear case having a cap portion which is covered, comprising a front casing which is put on the support plate so as to have a plurality of sound holes cover the vibrating membrane penetrating, its rear case, the cap part has a flat flange portion of the abutting annular flat portion of the support plate at substantially equal shape and the flat portion of the support plate to the tip from directly in front case via the flange or It is indirectly connected.
[0012]
In the present invention, a vent hole is formed through the support plate at the root of the magnet portion, a closing plate is disposed on the back side of the supporting plate, and the blocking plate is spaced slightly apart from the vent hole. It is also possible to have a configuration that overlaps with each other.
[0013]
Furthermore, in the present invention, it is preferable that the front case is provided with a bulging portion in which a region closer to one end from the central axis of the speaker portion is bulged in the direction of the central axis than the other regions.
Furthermore, in this invention, the structure which protrudes the protrusion part for insertion of the ear canal which has a sound passage hole in the protrusion front end from the area | region which was in the bulge part of the front case and was bulged more is also possible.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0015]
FIG. 1 is a cross-sectional view showing an embodiment of an earphone according to the present invention.
In FIG. 1, the support plate 29 has a recess 31 as a storage portion that is bent so that the substantially central portion of the disk-shaped thin steel plate is recessed in a columnar shape. It functions as.
[0016]
In the recess 31, the laminated thin columnar magnetized magnet portion 33 and the iron disk-shaped pole piece 35 are spaced from the inner peripheral wall of the recess 31 by a predetermined equal interval, and the magnet portion 33 is placed in the recess 31. It arrange | positions so that it may contact | abut to the inner bottom.
[0017]
A disc-shaped circuit board 37 serving as a relay board is disposed on the surface (outer surface) facing the contact surface (inner surface) of the magnet portion 33 at the bottom of the recess 31 so as to overlap the magnet portion 33 and the pole piece. 35 and a circuit board 37 are coaxially fixed to the support plate 29.
[0018]
That is, as shown in FIG. 2 and FIG. 3, at the bottom of the recess 31 of the support plate 29, a region overlapping with the magnet portion 33 or a slightly larger diameter region is rearward in the axial direction. The fixed plate 39 protrudes, and in other words, around the base of the magnet portion 33, a plurality of vent holes 41 are annularly dispersed and formed so as to penetrate the inner surface and the outer surface. ing.
[0019]
Therefore, the fixed plate 39 is supported and connected between the adjacent vent holes 41 at the bottom of the recess 31 and has a shape protruding further from the bottom.
[0020]
As a method of forming the concave portion 31, the fixing plate 39 and the vent hole 41 in the support plate 29, for example, the support plate 29 is drawn to form the concave portion 31, and a plurality of vent holes 41 are punched and formed at the bottom, and then It is conceivable that the fixed plate 39 is formed by slightly punching the region surrounded by the vent holes 41. The formation order and the processing method are not limited to this.
[0021]
As shown in FIG. 3, the fixing plate 39, the magnet portion 33, the pole piece 35, and the circuit board 37 are formed with substantially equal diameter through holes 39a, 33a, 35a, 37a coaxially. A grommet 43 (not shown in FIG. 1) is inserted into the through holes 37a, 39a, 33a, and 35a of the circuit board 37, the fixing plate 39, the magnet portion 33, and the pole piece 35 from the 37 side, and on the pole piece 35 side. The tip of the eyelet 43 is caulked on the pole piece 35, and the circuit board 37, the magnet portion 33, and the pole piece 35 are fixed to the support plate 29.
[0022]
In addition, the circuit board 37 is formed to have a diameter substantially the same as or slightly larger than the peripheral end of the vent hole 41 in the radial direction of the recess 31, and is stacked so as to close the vent hole 41 as shown in FIG. A slight slit-like space S is formed between the bottom of the support plate 29 and the vent hole 41 by the amount of the fixed plate 39 protruding, and the front and back sides of the support plate 29 are vented. That is, the circuit board 37 functions as a closing plate for the vent hole 41.
[0023]
Therefore, the substantial size of the vent hole 41 can be adjusted by adjusting the protruding amount of the fixed plate 39 from the bottom of the support plate 29 and the outer diameter of the circuit board 37.
Further, the support plate 29 has an annular upright portion 29a with its outer peripheral edge slightly bent, and an area from the concave portion 31 to the upright portion 29a is an annular flat portion 29b as shown in FIG. It has become.
[0024]
Returning to FIG. 1, a vibration film 45 made of a conventionally known polyester film (PET), for example, is disposed on the support plate 29 so as to cover the concave portion 31, and the periphery thereof is fixed to the upright portion 29 a.
[0025]
On the outer periphery of the magnet part 33 and the pole piece 35, for example, a conventionally known cylindrical voice coil 47 in which a polyurethane-coated conductive wire is wound in a cylindrical shape is loosely inserted between the side wall of the recess 31 and spaced apart. One end face of the voice coil 47 is supported by the vibration film 45, and the lead wire 47a is led out through the hollow portion 43a of the eyelet 43 and connected to the circuit board 37 to form a dynamic speaker portion. .
[0026]
A back case 49 molded from, for example, ABS resin is covered on the circuit board 37 side, that is, the back side of the support plate 29 so as to cover the recess 31.
[0027]
The back case 49 has a cap portion 49a that covers the circuit board 37 of the support plate 29 and fits into the recess 31, and an annular flange portion 49b having substantially the same shape as the flat portion 29b of the support plate 29 from the cap portion 49a to the tip. (See FIG. 4A), the flange portion 49b is brought into contact with the flat portion 29b of the support plate 29 and is appropriately fixed.
[0028]
On the vibration film 45 side, that is, the front surface side of the support plate 29, a front surface case 51 that is molded from, for example, ABS resin and has a slightly bulging shape and is relatively thick and relatively flat, covers the vibration film 45. It is covered like this.
[0029]
The front case 51 has a large number of small-diameter sound passages 53 formed so as to penetrate therethrough and, as will be described later, the thickness T of the region (upper side in the figure) facing the external auditory canal 25e when used is set to other values. It has a bulging portion 51a that bulges larger in the direction of the central axis X of the speaker portion than the thickness t of the region (see FIG. 4B).
[0030]
In FIG. 1, the symbol T indicates the axial thickness of the region of the bulging portion 51a that is closer to the upper side than the central axis X of the speaker portion, and the symbol t indicates the axial thickness of the region that is closer to the lower side. The bulging portion 51a is formed in the front case 51 so as to be an upper region in use.
[0031]
As shown in FIG. 5, the earphone of the present invention is used so as to fit in the ear canal cavity 25d formed between the antipod 25b, the tragus 25c and the ear ring 25f, and the upper region of the front case 51 is Since it is formed thicker than the lower region, the central axis X is slightly offset with respect to the central axis Y of the ear canal 25e that fits in the ear canal cavity 25d so that the speaker axis X is slightly upward. Or it is mounted so as to face each other in a matched state.
[0032]
In the earphone of the present invention, a cable for connecting to an external electronic device from the circuit board 37 is required, and a protective projection for protecting the cable from the back case 49 to the outside is provided in the back case. It is common to project integrally from 49. However, since it is not a main part of the present invention, illustration and detailed description are omitted.
[0033]
As described above, in the earphone of the present invention, the cylindrical recess 31 is formed at the center of the support plate 29, the bottom of the recess 31 is slightly protruded to the back side, and the fixing plate 39 is formed. The pieces 35 are stacked and fixed in the recess 31 so as to be placed on the fixing plate 39, and the circuit board 37 is fixed on the opposite surface side of the fixing plate 39, and the bottom of the recess 31 is near the root of the magnet portion 33. The support plate 29 is formed with an annular flat portion 29b on the outer periphery of the recess 31. The vibration film 45 is fixed to the support plate 29 so as to cover the recess 31, and the circuit board of the support plate 29 is formed. the 37 side or the rear side, the flat portion and the flange portion 49b with covering the recess 31 of the support plate 29 so that the rear case 49 having a flange portion 49b of the same shape and the flat portion covering the circuit board 37 It is brought into contact 9b, and is configured to fix the front case 51 having a plurality of sound holes 53 in the support plate 29 and the rear case 49 so as to cover the vibrating membrane 45.
[0034]
For this reason, the back case 49 is fixed to the support plate 29 and the front case 51 via the flat flange portion 49b in contact with the support plate 29, so that the vicinity of the open end of the back case 49 does not bulge out. The earphone easily fits in the ear canal cavity 25d, and unlike the conventional back case 15, the back case 49 does not unnecessarily press the antipod 25b or the tragus 25c.
[0035]
Therefore, it is difficult for the user to feel the pressure and pain from the back case 49 to the bead 25b and the tragus 25c, so that wearing comfort to the ear is ensured, and dropping from the ear can be reduced.
[0036]
In addition, a circuit board 37 is stacked on the bottom of the concave portion 31 of the support plate 29 so as to close the vent hole 41 formed near the base of the magnet portion 33 and to form a slight slit-like interval S. The air holes 41 are concealed by the circuit board 37 and the slit-shaped interval S can be reduced.
[0037]
Therefore, compared to the conventional vent 21, flux and solder debris scattered when soldering the lead wire 47 a of the voice coil 47 to the circuit board 35 are less likely to adhere to the vibration film 45 through the vent 41. There is no need to block the vent hole 41 with a breathable net or the like, and it is easy to reduce the cost due to a reduction in the number of components and manufacturing steps, and the two members of the fixing plate 39 and the circuit board 37 in which the vent hole 41 is formed. Thus, it is easy to form the interval S narrowly and the adjustment thereof is easy. Therefore, the frequency characteristics can be improved through the adjustment of the low frequency range.
[0038]
Incidentally, in the conventional earphone shown in FIG. 10, the vent hole 21 is generally formed by press working, but the inner diameter is 0.5 mm to 1.2 mm, and actually about 0.7 mm to 1.2 mm. The diameter is relatively large and fine adjustment of the inner diameter is difficult. In the vent hole 21 having an inner diameter of 0.5 mm or more, it is considered difficult to change the frequency characteristics even if the inner diameter is adjusted.
[0039]
On the other hand, according to the slit-like spacing S between the air vent 41 and the circuit board 37 as in the present invention, the spacing S can be finely adjusted from about 0.2 mm to about 1 mm. The adjustment is possible until a wide frequency band can be secured.
[0040]
Further, the front case 51 has a bulging portion 51a in which the thickness T of the region facing the ear canal 25e during use is larger than the thickness t of other regions in the central axis direction. The center axis X of the speaker unit formed by the unit 5, the vibration membrane 9, the voice coil 11, and the like is easier to face obliquely upward than the conventional configuration, and is generally inclined from the ear canal cavity 25d to the inside of the head 27. With respect to the ear canal 25e extending upward (see FIG. 12), the speaker axis X of the earphone is aligned with the central axis Y of the ear canal 25e or the angle of deviation is smaller than before, and the sound from the diaphragm 45 is transmitted to the ear canal 25e. It becomes easy to propagate along the direction center axis Y more directly.
[0041]
Therefore, it is difficult to lower the acoustic characteristics by reducing the sensitivity reduction and the attenuation of the bass and treble ranges, and it is possible to secure good Hi-Fi characteristics.
[0042]
As the above-described earphone, the configuration using the relatively flat disk-shaped front case 51 having a slightly bulging shape has been described, but the present invention is not limited to this.
[0043]
For example, as shown in FIG. 6, the protruding portion 57 for inserting the ear canal having the sound passage hole 55 at the protruding tip may be integrally protruded in the bulging portion 51 a of the front case 51.
[0044]
In addition, when the earphone according to the present invention is attached to the ear canal cavity 25d, the projecting portion 57 is inserted into the central axis Y of the ear canal 25e so as to be inserted into the ear canal 25e of a general user so as not to be uncomfortable. It protrudes at an angle and outer diameter selected empirically in a matching direction.
[0045]
As described above, in the configuration in which the protruding portion 57 protrudes from the bulging portion 51a of the front case 51, when the protruding portion 57 is inserted into the ear canal 25e as compared to the configuration shown in FIG. The gap between the ear canal cavity 25d or the ear canal 25e is almost eliminated and sound leakage is reduced, and the frequency characteristics are further improved as shown in FIG.
[0046]
In FIG. 7, the broken line is the frequency characteristic in the configuration as shown in FIG. 1 where the protrusion 57 is not provided, the solid line is the frequency characteristic in the configuration as shown in FIG. 6 where the protrusion 57 is provided, and the alternate long and short dash line is the conventional earphone. The frequency characteristics are shown.
[0047]
According to FIG. 7, it can be seen that even the configuration as shown in FIG. 1 without the protruding portion 57 can obtain frequency characteristics almost the same as those in the configuration as shown in FIG. 6 except that the bass range is easily attenuated. It can be seen that the conventional earphone is attenuated in both the low sound range and the high sound range.
[0048]
Furthermore, in the earphone of the present invention, as described above, the air hole 41 formed in the recess 31 is not limited to the configuration in which the circuit board 37 is used as a closing plate to form the narrow space S, and is shown in FIGS. Configuration is also possible.
[0049]
That is, a ring plate 59 integrally including a ring portion 59a and a cylindrical portion 59b extending in the axial direction from the inner side is used, and the cylindrical portion 59b is fitted on the outer periphery of the disc-shaped circuit board 37 to A configuration in which the ring portions 59a are overlapped with a slight interval is also possible. In FIG. 9, illustrations corresponding to the eyelets and insertion holes in FIG. 3 are omitted.
[0050]
In this way, in the configuration in which the ring plate 59 is overlapped as the closing plate on the outer periphery of the circuit board 37, unlike the configuration using only the circuit board 37 described above, it is easy to adjust the degree of fitting of the ring plate 59 with respect to the circuit board 37. Thus, the frequency characteristics can be adjusted even after the rising portions 29a and the vent holes 41 of the support plate 29 are formed, and the earphones having different frequency characteristics from the support plates 29 having the rising portions 29a and the vent holes 41 having the same shape. Is obtained.
[0051]
However, in the configuration using only the circuit board 37, the circuit board 37 for connecting the lead wire 47a from the voice coil 47 to the outside is also used, and the acoustic frequency characteristics can be greatly adjusted without increasing the number of parts. It is.
[0052]
Further, in the configuration described above, the lead wire 47a of the voice coil 47 is led out to the circuit board 37 side through the hollow portion 43a of the eyelet 43. However, in the present invention, at least the inner region of the annular flat portion 29b, for example, the concave portion described above If an appropriate insertion hole is formed in 31 and led out, the object of the present invention can be achieved.
[0053]
Further, in the earphone of the present invention, the flat portion 29b of the support plate 29 and the flange portion 49b of the back case 49 need not be completely annular, circular or ring-shaped, and the object of the present invention can be achieved even if it is C-shaped. Is possible.
[0054]
Furthermore, in the above-described present invention, the region of the front case 51 that extends upward from the central axis X of the speaker portion is the bulged portion 51a. However, depending on the overall shape of the earphone, the region may be shifted downward or to the left and right. It is also possible to adopt a configuration in which the bulging portion is a bulging portion, and if the bulging portion is formed by bulging a region closer to one end from the central axis of the speaker portion in the central axis direction than the other region, It is possible to achieve the purpose.
[0055]
In the implementation of the earphone of the present invention, the back case 49, the support plate 29, and the front case 51 can be configured to be fixed directly or indirectly with another member therebetween, The support plate 29 is not necessarily required to have the concave portion 31 for storage, and may be configured such that a speaker portion is formed on one side of a flat support plate and a circuit board 37 or the like is arranged on the opposite surface.
[0056]
【The invention's effect】
As described above, the present invention has a magnet part that forms the speaker part of the earphone, a support plate that supports the magnet part on one side and has an annular flat part formed around the magnet part, and a voice coil. A vibration film which is supported by a support plate so as to cover the magnet portion on the front side with a space therebetween and forms a speaker portion, and a support plate which has a plurality of sound passage holes therethrough and covers the vibration film a front case having a cap portion which is put on, and and a rear case end without arranged cup-like which is put on the support plate as the back side of the vibrating membrane, the rear case, the support plate from the cap portion to the distal end a flange portion abutting annular in its flat portion almost equal shape as the flat portion of, from being directly or indirectly connected to the front case via the flange portion, reforming the wearing comfort of the ear It can be reduced from falling out of the ear along with the can.
In the configuration where the ventilation hole is formed through the support plate at the base of the magnet part, the closing plate is arranged on the back side of the supporting plate, and this closing plate is overlapped with the ventilation hole at a slight interval. It is possible to reduce the number of manufacturing steps and reduce the cost while ensuring a good acoustic characteristic.
In addition, the configuration using the circuit board as the closing plate allows the circuit board to be used for connecting the lead wire from the voice coil to the outside, and has good acoustic frequency characteristics without increasing the number of parts and manufacturing steps. Can be maintained and adjusted.
In addition, the front case has a configuration in which a bulging portion in which a region closer to one end from the central axis of the speaker unit is bulged in the direction of the central axis than the other region has good acoustic characteristics when worn on the ear. Sensitivity and wide frequency characteristics can be ensured.
Furthermore, in the bulging portion of the front case and in the more bulging region, the structure in which the protruding portion for inserting the external auditory canal having the sound passage hole at the protruding tip protrudes, so that better acoustic sensitivity and wider frequency characteristics are obtained. Can be secured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an embodiment of an earphone according to the present invention.
FIG. 2 is a cross-sectional view of a principal part showing a cross section of the vicinity of a support plate and a magnet part in FIG. 1;
FIG. 3 is an exploded perspective view showing the vicinity of a support plate and a magnet part in FIG. 1 in an exploded manner.
4 is a perspective view showing a back case and a front case in FIG. 1. FIG.
5 is a cross-sectional view showing an example of use of the earphone according to FIG.
FIG. 6 is a cross-sectional view showing another form of the earphone according to the present invention together with a usage example.
FIG. 7 is a frequency characteristic diagram showing the present invention and a conventional earphone.
FIG. 8 is an exploded perspective view of a main part showing a circuit board and a ring portion fixed to the circuit board as another configuration of the earphone of the present invention.
9 is a cross-sectional view of the main part showing the vicinity of a support plate and a magnet part using the ring part of FIG. 8 in the earphone of the present invention.
FIG. 10 is a cross-sectional view showing a conventional earphone.
FIG. 11 is a perspective view schematically showing the structure of a human ear.
FIG. 12 is a cross-sectional view showing an example of use of a conventional earphone.
[Explanation of symbols]
1, 29 Support plate 1a, 29a Upright part 1b, 29b Flat part 3, 31 Concave part 5, 33 Magnet part 7, 35 Pole piece 9, 45 Vibration film 11, 47 Voice coil 11a, 47a Lead wire 13 Circuit board 15, 49 Rear case 17, 53, 55 Sound passage hole 19, 51 Front case 21, 41 Vent 23 Adhesive 25 Ear 25a Ring 25b Pearl 25c Tragus 25d Ear hole medial 25e Ear canal 25f Ear ring 27 Heads 33a, 35a, 37a 39a Through hole 37 Circuit board (blocking plate)
39 Fixing plate 43 Eyelet 43a Hollow portion 49a Cap portion 49b Flange portion 51a Protruding portion 57 Protruding portion 59 Ring plate (blocking plate)
59a Ring part 59b Tube part

Claims (4)

A magnet part that forms the speaker part of the earphone;
A support plate having an annular flat part formed around the magnet part on one side,
A vibrating membrane that has a voice coil and is supported by the support plate so as to cover the magnet portion with a gap on the front side thereof and to form the speaker portion;
A back case having a cap portion that covers the support plate with the side on which the vibration film is not disposed as the back side;
A front case that is covered with the support plate so as to cover the vibration membrane with a plurality of sound passage holes penetrating through;
Comprising
The back case has an annular flat flange portion that is substantially in the same shape as the flat portion of the support plate from the cap portion to the tip, and abuts against the flat portion, either directly or via the flange portion to the front case. An earphone characterized by being indirectly connected.   A vent hole is formed through the support plate at the root of the magnet portion, a closing plate is disposed on the back side of the support plate, and the closing plate is overlapped with the vent hole at a slight interval. Item 1. The earphone according to Item 1. 3. The earphone according to claim 1, wherein the front case has a bulging portion that bulges a region closer to one end from the central axis of the speaker unit in the direction of the central axis than the other region. 4. The earphone according to claim 3, wherein the front case has a protruding portion for inserting an ear canal having the sound passage hole at a protruding tip in a protruding region of the protruding portion. 5.

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