JP2009049757A - Ear-inserted type earphone - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ear-inserted type earphone which can be restrained from being easily dropped from the ear, while attaining improvement in volume and sound quality. <P>SOLUTION: The ear-inserted type earphone 1 comprises: a case 4; and a speaker unit 3 mounted on the relevant case 4 and including a vibration section 10 and a magnetic circuit section 9 which vibrates the vibration section 10. The vibration section 10 comprises a diaphragm 22 and a voice coil 20 which is fixed onto the diaphragm 22 and to which an audio current is supplied, to vibrate the diaphragm 22 in cooperation with the magnetic circuit section 9. The voice coil 20 is formed in a long plate shape and arranged in such a way that its lengthwise direction becomes parallel with the sound emission direction H of sound that is generated when the diaphragm 22 is vibrated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ear insertion type earphone that is inserted into the ear canal of a human ear, for example.

  Conventionally, various earphones (see, for example, Patent Document 1) have been used as ear-insertion-type earphones that can be attached to human ears. This type of earphone disclosed in Patent Document 1 includes a speaker unit that generates sound, and an earphone main body that houses the speaker unit and is attached to an auricle (also referred to as an ear shell). ing.

  The speaker unit includes a vibration part having a vibration plate that generates a sound by vibration when a sound current is applied, and a magnetic circuit part for vibrating the vibration part of the vibration part. It is formed in a shape.

  The earphone body includes a cylindrical portion that can be attached to the auricle and that houses the speaker unit. The cylindrical portion is such that the diaphragm of the speaker unit is exposed and accommodates the speaker body.

  In the earphone configured as described above, the cylindrical portion of the earphone main body is attached to the auricle of a person or the like, a sound current is applied to the voice coil of the speaker unit, and the diaphragm of the vibration unit vibrates to generate sound. The sound (also referred to as sound information) is transmitted to the person described above.

  In addition, since the earphone shown in Patent Document 1 of this kind is formed in a disk shape of the speaker unit, it is difficult to insert the earphone into the ear canal, and it can be easily detached from the ear. End up. In addition, it is necessary to open the front side of the speaker unit (above the diaphragm), and the earphone has a structure with poor airtightness. Therefore, for example, it is difficult to expand the bass reproduction band.

In order to solve this type of problem, that is, to be miniaturized and inserted into the ear canal, an earphone including a so-called balanced armature type speaker unit has been proposed (for example, see Patent Document 2).
JP-A-11-225387 JP 2007-74499 A

  The earphone disclosed in Patent Document 1 described above is difficult to downsize the speaker unit until it can be inserted into the ear canal and easily falls off the ear.

  The earphone disclosed in Patent Document 2 can be downsized until it can be inserted into the ear canal, but the balanced armature type speaker unit vibrates the diaphragm via a lever. The improvement in efficiency and the expansion of the bass reproduction band have the opposite characteristics. For this reason, it is difficult for the earphone disclosed in Patent Document 2 to improve the volume and sound quality.

  This invention makes it an example of a subject to cope with such a problem. An object of the present invention is, for example, to provide an ear insertion type earphone that can prevent a dropout from an ear easily while improving sound volume and sound quality.

  In order to solve the above problems and achieve the object, an ear insertion type earphone according to claim 1 of the present invention is a speaker unit having a casing, a vibration section attached to the casing, and a magnetic circuit section. And the vibration portion includes a diaphragm and a voice coil, and the voice coil is formed in a long flat plate shape, and the sound produced when the diaphragm vibrates in the longitudinal direction. It is characterized by being arranged substantially parallel to the radial direction.

  Hereinafter, an embodiment of the present invention will be described. In the ear insertion type earphone according to one embodiment of the present invention, the voice coil is directly fixed to the diaphragm, so that the speaker unit is a so-called dynamic type so as to improve the sound volume and sound quality. It is possible to reduce the size of the speaker unit to a size that can be inserted into the ear canal by arranging it in the shape of a long flat plate and placing its longitudinal direction parallel to the direction of sound emitted when the diaphragm vibrates. Yes.

  Further, the ear insertion type earphone of the present embodiment is provided with a voice coil housing portion at the center portion of the diaphragm main body formed in a thin plate shape and a long flat plate shape of the vibration portion. Can be fixed, and the volume and sound quality can be improved.

  Further, an opening for sound emission may be provided on the front end surface of the housing. In this case, the sound generated by the speaker unit can be easily guided into the ear canal.

  In addition, since the earphone main body that accommodates the housing and the speaker unit is provided, it is possible to prevent the speaker unit or the like from being damaged or contaminated with foreign matter.

  Furthermore, since the earphone main body is formed in a cylindrical shape, the speaker unit and the like can be accommodated without preventing the sound generated by the speaker unit from being guided into the ear canal.

  You may provide the space | interval holding | maintenance part which hold | maintains the space | interval of the magnet by which the different polarities of a magnetic circuit part mutually arrange | position. In this case, since the distance between the magnets is kept constant along the longitudinal direction of the voice coil and the vibrating part or earphone, the magnetic gap formed by these magnets is in the longitudinal direction of the voice coil and the vibrating part or earphone. Non-uniformity (variation) can be suppressed.

  The interval holding unit may be made of a nonmagnetic material. In this case, it is possible to prevent the gap holding portion from being excited and the magnetic gap formed by the magnet from becoming nonuniform (variable) in the longitudinal direction of the voice coil and the vibrating portion, that is, the earphone.

  The magnetic circuit unit may include a plate and a frame. In this case, since the magnet and the plate are attached to the frame, it is possible to prevent the magnetic gap formed by the magnet from becoming non-uniform (variable) in the longitudinal direction of the voice coil and the vibrating part, that is, the earphone.

  The magnetic circuit unit may fill the magnetic fluid between the pair of plates. In this case, the vibration of the diaphragm can be prevented from becoming uneven in the longitudinal direction of the diaphragm, that is, the diaphragm can be prevented from rolling, the diaphragm or the voice coil can be prevented from contacting the plate, etc. Abnormal noise can be prevented from occurring. Further, it is not necessary to provide a damper, and the earphone can be downsized.

  You may provide a space | interval holding | maintenance part in a flame | frame. In this case, an increase in the number of parts can be suppressed, and an increase in cost can be suppressed.

  Since the lead wire connected to the voice coil is guided to the outside along the width direction of the diaphragm from the longitudinal center portion of the diaphragm, the lead wire is connected to the lead wire by vibration (reverse resonance, etc.) of the diaphragm. It is possible to suppress the application of tension (force that pulls the lead wire) and to prevent the lead wire from being damaged.

  An embodiment of the present invention will be described with reference to FIGS. An ear insertion type earphone 1 (hereinafter simply referred to as an earphone) shown in FIG. 1 is inserted into an external auditory canal O (shown in FIG. 1) of an ear of a person or the like to produce a sound, and this sound (also referred to as sound information). To the people mentioned above.

  As shown in FIG. 1, the earphone 1 includes an earphone main body 2, a speaker unit 3 that generates sound, and a housing 4.

  As shown in FIG. 1, the earphone main body 2 includes a housing portion 5 and a spherical portion 6. Both the accommodating part 5 and the spherical part 6 are made of resin or the like. The accommodating part 5 is integrally provided with a bottom part 7 and a cylindrical part 8 erected from the outer edge of the bottom part 7 and is formed in a cylindrical shape that can be inserted into the external auditory canal O of an ear of a person or the like.

  The spherical portion 6 is formed in a cylindrical shape having a substantially spherical outer shape, and is formed to be a size that can be inserted into the ear canal O of an ear of a person or the like, or to be a stopper when the earphone 1 is inserted into the ear canal O. Has been. The spherical portion 6 is attached to the outer periphery of one end portion on the side away from the bottom portion 7 of the housing portion 5. Further, the spherical portion 6 is formed in a cylindrical shape with both ends opened, and the opening 29 is exposed without covering an opening 29 described later provided in the housing 4.

  The earphone main body 2 includes a cylindrical storage portion 5 and a cylindrical spherical portion 6 attached to the outer periphery of the storage portion 5 and is formed in a cylindrical shape as a whole. The earphone main body 2 houses the housing 4 and the speaker unit 3 inside the housing portion 5 and the spherical portion 6.

  The speaker unit 3 includes a magnetic circuit unit 9 and a vibration unit 10 as shown in FIGS.

  The magnetic circuit unit 9 includes a frame 11 made of a non-magnetic material, a yoke 12 made of a magnetic material (so-called paramagnetic material or ferromagnetic material), a pair of magnets 13, and a magnetic material (so-called so-called And a pair of plates 14 made of a paramagnetic material or a ferromagnetic material.

  As shown in FIG. 3, the frame 11 is integrally formed with a pair of linear portions 15, a pair of connecting portions 16, and a gap holding portion 17. That is, the frame 11 is provided with an interval holding part 17 made of a nonmagnetic material. Each of the straight portions 15 is formed in a strip shape extending linearly. The pair of linear portions 15 are arranged in parallel with a space therebetween. The straight portions 15 are formed so that the cross-sectional shape thereof is rectangular, and the longitudinal directions of the cross-sections are located on substantially the same line.

  The connecting portion 16 connects the ends of the pair of straight portions 15. The interval holding portion 17 extends from the end surfaces of the pair of connecting portions 16 so as to protrude linearly along the longitudinal direction of the linear portion 15. The interval holding unit 17 is disposed between the pair of linear portions 15. The interval holding unit 17 is disposed between the pair of magnets 13, restricts the magnets 13 from approaching each other and coming into contact with each other, and holds the interval between the pair of magnets 13.

  As shown in FIG. 5, the frame 11 has one surface of the straight portion 15 and the connecting portion 16 formed continuously and flat. Further, the frame 11 is formed with the frame portion 18 erected from the outer edge of the one surface described above, extending over the straight portion 15 and the connecting portion 16, that is, over the entire circumference.

  Further, a notch portion 31 is formed below the straight portion 15. The formation of the notch 31 prevents the frame 11 from being deformed by the magnetic force between the pair of magnets 13 to be non-uniform (variable) in the interval between the straight portions 15, particularly in the longitudinal direction. ing.

  The yoke 12 is formed in a band plate shape, and the back side of the speaker unit 3 (below the diaphragm 22) is sealed. The yoke 12 is formed so that its planar shape is substantially equal to the planar shape of the outer edge of the frame 11 and is slightly smaller than the frame 11.

  The magnets 13 are each formed in a strip shape extending linearly, and are formed in substantially the same size and shape as the straight portion of the frame 11. The magnets 13 are arranged on the yoke 12 so as to be spaced apart from each other in parallel. The magnet 13 is magnetized so that one surface side thereof becomes one of the N pole and S pole, and the other surface side becomes magnetized. For example, in FIG. 2, the left magnet 13 is magnetized so that the front side is N-pole and the back side is S-pole, and the right-side magnet 13 is magnetized so that the front side is S-pole and the back side is N-pole. Has been.

  Each of the plates 14 is formed in a strip shape extending linearly, and is formed in substantially the same size and shape as the linear portion 15 and the magnet 13 of the frame 11. The plates 14 are arranged parallel to each other at intervals, and are stacked on the magnets 13 respectively.

  In the magnetic circuit unit 9, a pair of magnets 13 and a pair of plates 14 are sequentially stacked on the yoke 12, the pair of plates 14 are overlapped with the linear portion 15 of the frame 11, and the pair of plates 14 and the pair of magnets 13 are mutually connected. It is assembled by positioning the gap holding portion 17 therebetween. As described above, the pair of magnets 13 and the pair of plates 14 are attached to the frame 11. At this time, the longitudinal directions of the yoke 12, the pair of magnets 13, and the pair of plates 14 are disposed substantially parallel to each other, and the pair of magnets 13 are disposed in a state in which different polarities face each other with a gap therebetween. ing.

  With the above-described configuration, the magnetic circuit unit 9 forms a magnetic gap G between the pair of plates 14.

  As shown in FIGS. 2 and 5, the vibration unit 10 includes a diaphragm 22, a voice coil 20, and a pair of lead wires 21 (shown in FIG. 6).

  The diaphragm 22 is made of resin and is formed in a thin plate shape. The diaphragm 22 is integrally provided with a diaphragm main body 23 formed in a flat plate shape that is vertically long in plan view, that is, a voice coil housing portion 24 provided at the center of the diaphragm main body 23. The diaphragm main body 23 is formed so that the planar shape thereof is substantially equal to the shape of the portion surrounded by the inner surface of the frame portion 18 of the frame 11. The diaphragm main body 23 is formed in a substantially arc shape in cross section with the central portion as a boundary. The diaphragm body 23 has a groove 32 formed at the end thereof. The groove 32 suppresses the occurrence of split vibration, split resonance, or the like in the diaphragm main body 23. The diaphragm main body 23 is overlaid on the one surface of the frame 11 and the outer edge thereof is fixed to the one surface of the frame 11 with an adhesive or the like. Thus, since the outer edge of the diaphragm main body 23 is fixed to the frame 11 with the adhesive, the diaphragm 22 separates the space on the front side and the space on the back side of the diaphragm 22.

  The voice coil housing portion 24 is provided in the center portion of the diaphragm main body 23 and extends linearly along the longitudinal direction of the diaphragm main body 23. The voice coil housing portion 24 has a cross-sectional shape having a pair of plates 14 or an outer peripheral portion and a bottom portion extending from the central portion of the diaphragm body 23 toward the sound radiation direction, and is formed in a groove shape. Yes.

  The voice coil 20 is formed in a long flat plate shape as a whole, and as shown in FIGS. 1 and 2, a pair of substantially parallel linear portions 25 and an arc shape in which both ends of these linear portions 25 are connected. The connecting portion 26 is formed in a rectangular shape. The length of the voice coil 20 in the longitudinal direction is formed substantially equal to the length of the voice coil housing portion 24. The voice coil 20 is configured to be wound along a planar shape thereof, and an audio current supplied via a lead wire 21 described later flows along the planar shape.

  The voice coil 20 is housed in the voice coil housing portion 24 and fixed to the voice coil housing portion 24, that is, the diaphragm 22 with an adhesive or the like. At this time, the pair of linear portions 25 are disposed substantially parallel to the frame 11, the magnet 13, and the plate 14, and one linear portion 25 is disposed in the magnetic gap G described above. Further, the voice coil 20 is arranged such that the longitudinal direction in the cross section of the linear portion 25 is parallel to the vibration direction of the diaphragm 22 of the vibration portion 10.

  The lead wire 21 is electrically connected to both ends of the voice coil 20 and supplies a voice current to the voice coil 20. As shown in FIG. 6, the lead wire 21 extends from the center portion in the longitudinal direction of the diaphragm 22 in the width direction of the diaphragm 22 (direction perpendicular to the vibration direction S of the diaphragm 22). Extends from. The direction in which the lead wire 21 is drawn from the voice coil 20 is any of the longitudinal direction of the diaphragm 22, the width direction of the diaphragm 22, the vibration direction of the diaphragm 22, or the direction substantially orthogonal to the vibration direction of the diaphragm 22. It doesn't matter. In particular, the width direction of the vibration plate 22, the vibration direction of the vibration plate 22, or the direction substantially orthogonal to the vibration direction of the vibration plate 22 is preferable in that it prevents excessive tension or the like from acting on the lead wire 21. Further, the position where the lead wire 21 is pulled out from the voice coil 20 is not particularly limited, but the lead wire 21 is closer to the position where the lead wire 21 is pulled out from the central portion in the longitudinal direction of the diaphragm 22. It is preferable in that it is possible to suppress contact with the like and the generation of abnormal noise due to contact. Further, although not shown, a lead-out passage communicating with the outside may be formed in the plate 14, the magnet 13, and the frame 11, and the lead wire 21 may be passed through the lead-out passage, and contact between the diaphragm 22 and the lead wire 21 occurs. That is, it is possible to prevent the acoustic characteristics from being deteriorated by contact.

  When the voice current is supplied to the voice coil 20 through the lead wire 21 in the above-described speaker unit 3, the voice coil 20 and the magnetic circuit unit 9 cooperate to cause the diaphragm main body 23 of the diaphragm 22 to move. The vibration plate body 23 of the vibration plate 22, that is, the vibration unit 10, is vibrated along the direction S perpendicular to both the longitudinal direction of the vibration plate body 23 and the direction in which the pair of plates 14 face each other. Generates a sound that responds. That is, the magnetic circuit unit 9 vibrates the vibration unit 10 to generate sound. Thus, the speaker unit 3 is arranged in a state where the longitudinal direction of the voice coil 20 is orthogonal to the vibration direction of the diaphragm 22. A direction S perpendicular to both the longitudinal direction of the diaphragm main body 23 and the direction in which the pair of plates 14 face each other forms the vibration direction of the diaphragm 22.

  The housing 4 includes a ceiling plate portion 27 having a planar shape substantially equal to the planar shape of the frame 11 and a plurality of side plate portions 28 erected from the outer edge of the ceiling plate portion 27. Is formed. The casing 4 is attached to the frame 11, that is, the speaker unit 3, with the ceiling plate portion 27 facing the diaphragm 22 attached to the frame 11 with a space and the side plate portion 28 overlapping the outer surface of the frame 11. Thus, the vibration unit 10 of the speaker unit 3, that is, the diaphragm 22 is covered.

  The housing 4 is attached to the speaker unit 3 and is housed in the earphone main body 2 together with the speaker unit 3. At this time, of course, the longitudinal directions of the earphone main body 2, the speaker unit 3, and the housing 4 are substantially parallel to each other. As shown in FIG. 4, an opening 29 is provided on the distal end surface 4 a of the housing 4 that is positioned at the deepest end of the external auditory canal O when inserted into the external auditory canal O. Of course, the opening 29 penetrates the side plate portion 28 of the housing 4 and opens the above-described distal end surface 4a. The opening 29 extends linearly along the longitudinal direction of the voice coil 20 and the magnetic circuit unit 9 described above. The opening 29 radiates sound generated when the diaphragm 22 of the vibration unit 10 of the speaker unit 3 vibrates through the inside along the longitudinal direction H to the back of the ear canal O.

  That is, the opening 29 is used for radiating sound generated by the vibration of the diaphragm 22 of the vibration unit 10 of the speaker unit 3 described above (that is, the sound emission opening). In addition, the longitudinal direction of the opening 29 described above forms a radiation direction H (indicated by an arrow in FIG. 1) of sound generated when the diaphragm 22 of the vibration unit 10 vibrates. Thus, the voice coil 20 is arranged such that its longitudinal direction is substantially parallel to the radial direction H described above.

  The earphone 1 having the above-described configuration is assembled such that the casing 4 is attached to the speaker unit 3 so as to cover the diaphragm 22, and the casing 4 and the speaker unit 3 are accommodated in the earphone main body 2. The earphone 1 is inserted into the ear canal O, and the audio current is supplied to the voice coil 20 via the lead wire 21 to generate a sound corresponding to the audio current and transmit the sound to a person or the like. .

  According to the present embodiment, by fixing the voice coil 20 to the diaphragm 22, the speaker unit 3 is a so-called dynamic type in which the voice coil 20 directly vibrates the diaphragm 22, so that, for example, improvement in efficiency is achieved. The vibration with a large amplitude is suppressed by suppressing the vibration of the voice coil 20 from being attenuated until it is transmitted to the diaphragm 22 as seen in the Riffel type speaker unit having the characteristic that the expansion of the bass reproduction band is contradictory. 22 can be vibrated, and a large sound pressure can be obtained.

  Further, since the voice coil 20 directly vibrates the diaphragm 22 in the speaker unit 3, the minimum resonance frequency can be reduced, and a large reproduction band can be obtained from the low sound range to the mid sound range and from the mid sound range to the high temperature range.

  Furthermore, since the diaphragm 22 of the speaker unit 3 separates the space on the front side and the space on the back side of the diaphragm 22, sound waves generated on the back side of the diaphragm 22 are generated on the front surface of the diaphragm 22. It is possible to suppress mixing with sound waves generated on the side, suppress a decrease in sound pressure, and obtain good acoustic characteristics. Further, the output sound pressure frequency characteristic can be flattened from the low sound range to the mid sound range and from the mid sound range to the high sound range (the occurrence of peak dip can be suppressed). Therefore, the volume and sound quality can be improved.

  Further, the voice coil 20 is formed in a long flat plate shape, and the longitudinal direction thereof is perpendicular to the vibration direction S of the diaphragm 22 and parallel to the radiation direction H, so that the speaker unit 3 is placed in the ear canal O. The size can be reduced to a size that allows insertion. For this reason, since the earphone 1 can be inserted into the external auditory canal O, the earphone 1 can be efficiently provided without causing the earphone 1 to easily fall off the external auditory canal O.

  Accordingly, the earphone 1 can prevent the earphone 1 from being easily dropped from the ear while improving the sound volume and the sound quality.

  Further, since the earphone 1 can be inserted into the ear canal O, the earphone 1, particularly the spherical portion 6 and the ear canal O, can improve the sealing performance.

  In the above-described embodiment, the earphone main body 2 includes the housing portion 5 and the spherical portion 6, but is not limited to this. For example, the spherical portion 6 may have an elliptical sphere shape or the like. As long as the earphone main body 2 can be inserted into the external auditory canal O or the airtightness with the external auditory canal O can be maintained, a known shape may be used.

  In addition, since the earphone 1 is provided with the voice coil housing portion 24 at the center portion of the vibration plate body 23 formed in a thin and long flat plate shape of the vibration portion 10, the voice coil 20 and the vibration plate 22 are connected to each other. It can be fixed and the volume and sound quality can be improved.

  Furthermore, since the opening 29 for sound emission is provided in the front end surface 4a of the housing 4, the sound generated by the speaker unit 3 can be easily guided into the ear canal O.

  Further, since the earphone main body 2 that accommodates the housing 4 and the speaker unit 3 is provided, it is possible to prevent the speaker unit 3 and the like from being damaged or contaminated with foreign matter.

  Furthermore, since the earphone main body 2 is formed in a cylindrical shape, the speaker unit 3 and the like can be accommodated without preventing the sound generated by the speaker unit 3 from being guided into the external auditory canal O.

  Since the magnetic circuit unit 9 includes the interval holding unit 17 that holds the interval between the magnets 13 that are arranged opposite to each other, the voice coil 20 and the vibrating unit 10, that is, along the longitudinal direction of the earphone 1, The interval between the magnets 13 is kept constant. Accordingly, it is possible to prevent the magnetic gap G formed by these magnets 13 from becoming nonuniform (variable) in the longitudinal direction of the voice coil 20 and the vibration unit 10, that is, the earphone 1.

  Since the interval holding unit 17 is made of a nonmagnetic material, the interval holding unit 17 is excited and the magnetic gap G formed by the magnet 13 is not aligned in the longitudinal direction of the voice coil 20 and the vibrating unit 10, that is, the earphone 1. Uniformity (variation) can be suppressed.

  Since the magnetic circuit unit 9 includes at least a pair of plates 14 and a frame 11 that are superposed on the magnet 13, the magnet 13 and the plate 14 are attached to the frame 11, so that the magnetic gap G formed by the magnet 13 is It is possible to suppress non-uniformity (variation) in the longitudinal direction of the voice coil 20 and the vibration unit 10, that is, the earphone 1.

  Since the space | interval holding | maintenance part 17 is provided in the flame | frame 11, the increase in a number of parts can be suppressed and the increase in cost can be suppressed.

  Since the lead wire 21 connected to the voice coil 20 is guided to the outside along the width direction of the diaphragm 22 from the longitudinal center portion of the diaphragm 22, the lead wire 21 is caused by the vibration of the diaphragm 22. It is possible to prevent the tension (force pulling the lead wire) from being applied to the lead wire 21 and to prevent the lead wire 21 from being damaged.

  In the embodiment described above, a pair of plates 14 are provided. However, in the present invention, a plurality of pairs of plates 14 may be provided as shown in FIG. In the example shown in FIG. 7, two pairs of plates 14 (a total of four plates 14 are provided) are provided without providing the yoke 12, and each plate 14 is superimposed on the magnet 13. Further, in FIG. 7, a magnetic gap G is formed between each pair of plates 14 (that is, two magnetic gaps G are formed).

  In the example shown in FIG. 7, the magnetic fluid 30 is filled between the pair of plates 14 and between the pair of plates 14 and the diaphragm 22. The magnetic fluid 30 is configured by mixing magnetic powder in a semi-solid resin having viscosity. The magnetic fluid 30 generates noise due to contact between the plate 14 and the diaphragm 22 or the voice coil 20 when an audio current is supplied to the voice coil 20, and the diaphragm 22 in the low frequency range. Unnecessary vibration can be suppressed. Further, by using the magnetic fluid 30, the magnetic flux density near the voice coil 20 can be increased.

  In the case shown in FIG. 7, since the magnetic circuit unit 9 fills the magnetic fluid 30 between the pair of plates 14 among the plurality of pairs of plates 14, the vibration of the diaphragm 22 is caused by the magnetic fluid 30. Since the vibration is gradually attenuated, it is possible to prevent the vibration of the diaphragm 22 from becoming uneven in the longitudinal direction of the diaphragm 22, that is, to suppress the rolling of the diaphragm 22, and to generate abnormal noise. Can be suppressed.

  In the example shown in FIG. 7, two pairs of plates 14 are provided, and a gel-like magnetic fluid 30 is filled between the pair of plates 14. However, in the present invention, three or more pairs (ie, a plurality) of the plates 14 may be provided, and the gel-like magnetic fluid 30 may be filled between at least a pair of the plates 14 among the plurality of plates 14.

  Further, in the example shown in FIG. 7, since the magnetic fluid 30 is filled between the pair of plates 14, the back side of the speaker unit 3 (below the diaphragm 22) is hermetically sealed. It is possible to improve the characteristics, particularly to expand the bass reproduction band.

  The inventors of the present invention have confirmed the effect of the present invention by calculating the vibration mode of the diaphragm 22 in simulation. The result of this simulation is shown in FIG. In this simulation, the vibration mode of the diaphragm 22 was calculated.

  According to FIG. 8, both end portions in the longitudinal direction of the diaphragm 22 vibrate upward in FIG. 8 (direction in which the diaphragm 22 approaches the ceiling plate portion 27 of the housing 4), and the center portion in the longitudinal direction of the diaphragm 22. However, it was clarified that it vibrates downward in FIG. 8 (the direction in which the diaphragm 22 moves away from the ceiling plate portion 27 of the housing 4) (occurrence of reverse resonance).

  For this reason, as shown in FIG. 9, when the lead wire 21 is pulled out along the longitudinal direction of the diaphragm 22 as in the comparative example shown in FIG. 9, excessive tension acts on the lead wire 21, It becomes clear that there is a high possibility that the lead wire 21 is damaged, and the lead wire is extended by extending in the width direction of the diaphragm 22 (direction substantially orthogonal to the vibration direction of the diaphragm 22) as in the above-described embodiment. It has been clarified that the lead wire 21 can be prevented from being damaged without excessive tension acting on the wire 21.

  According to the embodiment described above, the following ear insertion type earphone 1 is obtained.

(Additional remarks) The housing 4 and the speaker unit 3 having the vibration unit 10 and the magnetic circuit unit 9 attached to the housing 4 are provided. The vibration unit 10 includes the vibration plate 22, the voice coil 20, and the voice coil 20. With
The ear insertion type characterized in that the voice coil 20 is formed in a long flat plate shape, and its longitudinal direction is arranged substantially in parallel with a radiation direction H of a sound generated when the diaphragm 22 vibrates. Earphone 1.

  According to the supplementary notes, the voice coil 20 is directly fixed to the diaphragm 22, so that the speaker unit 3 is a so-called dynamic type to improve the sound volume and sound quality, and the voice coil 20 is formed into a long flat plate shape. The speaker unit 3 can be downsized to a size that can be inserted into the external auditory canal O by forming and arranging the longitudinal direction of the speaker unit 3 substantially parallel to the radiation direction H of the sound generated when the diaphragm 22 vibrates.

  In addition, the Example mentioned above only showed the typical form of this invention, and this invention is not limited to an Example. That is, various modifications can be made without departing from the scope of the present invention.

1 is a cross-sectional view of an ear insertion type earphone according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of a speaker unit of the ear insertion type earphone shown in FIG. 1. It is the disassembled perspective view which looked at the speaker unit shown by FIG. 2 from the downward direction. FIG. 3 is a perspective view of the speaker unit and the like shown in FIG. 2. It is sectional drawing which follows the VV line in FIG. FIG. 3 is a plan view of a diaphragm and the like of the speaker unit shown in FIG. 2. It is sectional drawing of the modification of the speaker unit shown by FIG. It is explanatory drawing which shows the simulation result of the vibration mode of the diaphragm of the speaker unit shown by FIG. It is a top view of comparative examples, such as a diaphragm of a speaker unit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Ear-insertion type earphone 2 Earphone main body 3 Speaker unit 4 Case 4a Front end surface 9 Magnetic circuit part 10 Vibration part 11 Frame 13 Magnet 14 Plate 17 Space | interval holding | maintenance part 20 Voice coil 21 Lead wire 22 Diaphragm 23 Diaphragm main body 24 Voice Coil housing part 29 Opening part 30 Magnetic fluid H Radiation direction O Ear canal

Claims (13)

A housing unit, and a speaker unit having a vibration unit and a magnetic circuit unit attached to the housing, wherein the vibration unit includes a diaphragm and a voice coil,
An ear insertion type earphone, wherein the voice coil is formed in a long flat plate shape, and the longitudinal direction of the voice coil is arranged substantially in parallel with a direction in which sound is generated when the diaphragm vibrates. The diaphragm is
A thin plate-like diaphragm main body formed in a long flat plate shape;
The ear insertion type earphone according to claim 1, further comprising: a voice coil housing portion that houses the voice coil.   The ear insertion type earphone according to claim 1, wherein the casing is formed in a long flat plate shape, and is attached to the speaker unit so as to cover the speaker unit.   The ear insertion type earphone according to any one of claims 1 to 3, wherein an opening for sound emission is provided at a front end surface of the housing.   The ear-insertion-type earphone according to any one of claims 1 to 4, further comprising an earphone main body that accommodates the casing and the speaker unit.   The said magnetic circuit part is provided with a pair of magnet arrange | positioned so that a different pole may mutually oppose, and a space | interval holding | maintenance part, The Claim 1 thru | or 5 characterized by the above-mentioned. Ear insertion type earphone.   The ear-insertion-type earphone according to claim 6, wherein the interval holding portion is made of a nonmagnetic material.   The ear insertion type according to any one of claims 1 to 7, wherein the magnetic circuit unit includes a plate, a magnet, and a frame to which the plate and the magnet are attached. Earphones. The magnetic circuit unit includes a pair of the plates,
9. The ear insertion type earphone according to claim 8, wherein a magnetic fluid is filled between the pair of plates.   The ear insertion type earphone according to any one of claims 6 to 9, wherein the frame includes the interval holding unit. The vibrating portion includes a lead wire electrically connected to the voice coil,
The ear insertion type earphone according to any one of claims 1 to 10, wherein the lead wire extends in a direction substantially perpendicular to a longitudinal direction of the voice coil.   The ear insertion type earphone according to claim 8, wherein the frame has a notch.   The earphone main body which accommodates the said housing | casing and the said speaker unit is provided, The said earphone main body is equipped with an accommodating part and a spherical part, The Claim 1 thru | or 3 characterized by the above-mentioned. Ear-insertion type earphone.

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