Patent Translate Powered by EPO and Google Notice This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate, complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or financial decisions, should not be based on machine-translation output. DESCRIPTION JP2003102092 [0001] BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroacoustic transducer which can be used as a speaker or a receiver, and more particularly to an electroacoustic transducer provided with two electroacoustic transducer units. [0002] 2. Description of the Related Art JP-A-7-203589 describes this type of electroacoustic transducer. The electro-acoustic transducer described in the publication is supposed to be used as a two-way radiation speaker, and has an internal structure shown in FIG. That is, the top plate 2 and the inner plate 3 are superimposed on the magnet 1 with the ring-shaped magnet 1 interposed therebetween, and pole portions 4 and 5 which protrude to the front and back sides of the inner plate 3 at the center part of the inner plate 3 Is provided. Further, an outer yoke 6 is extended to the outer peripheral portion of the top plate 2. And, in addition to the magnetic gap G1 being formed by the gap space between the pole portion 4 on one side provided on the inner plate 3 and the opening edge 2a provided at the center of the inner plate 2, A magnetic gap G2 different from the magnetic gap G1 is formed by the clearance space between the pole 5 on the other side provided in 3 and the opening edge 6a provided in the outer yoke 6. [0003] 13-05-2019 1 Further, in the electroacoustic transducer of FIG. 8, two diaphragms 7 and 8 are disposed in a state in which their back surfaces face each other, and the same diaphragms 7 and 8 are separately provided. Voice coils 9, 10 of a diameter are separately arranged in the magnetic gaps G1, G2 described above. Reference numerals 11 and 12 denote dampers provided corresponding to the respective diaphragms 7 and 8, and reference numerals 13 and 14 denote frames provided corresponding to the respective diaphragms 7 and 8. [0004] In the electroacoustic transducer shown in FIG. 8, by applying independent input signals to the two voice coils 9, 10, it is possible to drive the two diaphragms 7, 8 independently. [0005] On the other hand, in an electronic device used as a portable terminal device such as a mobile phone, in order to have a transmitting function and a receiving function, the electronic device needs to have a speaker and a receiver. FIG. 9 schematically shows the internal structure of a conventional portable terminal (mobile phone), and 21 is a flat hollow case, in which case the receiver 22, the speaker 23, the liquid crystal display A device (LCD) 24 or the like is incorporated, the receiver 22 is disposed facing the sound hole 26 of the inner side wall 25 of the case 21, and the speaker 23 is disposed facing the sound hole 29 of the outer side wall 28 of the case 21 There is. [0006] In the electro-acoustic transducer described in FIG. 8, the voice coil provided on each of the two diaphragms 7 and 8 disposed on both sides of the inner plate 3. Since 9, 10 have the same diameter, two spaces S1, S2 allowing displacement of each voice coil 9, 10 due to the vibration of the respective diaphragms 7, 8 are provided on both sides of the inner plate 3 It is secured. Therefore, according to this electro-acoustic transducer, the total thickness dimension T1 includes the combined length of the heights of the two spaces S1 and S2. Therefore, regardless of how the shapes of the diaphragms 7 and 8 and the shape of the outer yoke 6 are changed, the place for securing the two spaces S1 and S2 shortens the total thickness dimension T1 to perform electroacoustics. It is an obstacle to reducing the thickness of the converter. 13-05-2019 2 [0007] Also, in the portable terminal device described in FIG. 9, even if the receiver 22 and the speaker 23 provided inside the case 21 are thin and their thickness dimensions R1 and S1 are short, In the case where the receiver 22 and the speaker 23 are distributed in opposite directions in the inside of the case 21 as in the above, the total thickness dimension T2 of the case 21 becomes long. In particular, in the electro-acoustic transducer in which the receiver 22 and the speaker 23 are disposed with the liquid crystal display device 24 interposed as shown in FIG. 9, the thickness dimension R1 of the receiver 22 and the speaker Since the thickness dimension S1 of 23 is included, there is a situation where it is difficult to reduce the total thickness dimension T1 of the case 21. [0008] The present invention has been made under the circumstances described above, and has two diaphragms, and the two diaphragms can be operated independently to exhibit a transmitting function and a receiving function. However, by devising that the combined length dimension of the space for allowing displacement of the two voice coils fixed to each diaphragm is not included in the entire thickness dimension, An object of the present invention is to provide an electro-acoustic transducer which can be easily thinned by shortening the entire thickness dimension. [0009] Another object of the present invention is to provide an electroacoustic transducer capable of reducing the cost by reducing the number of parts. [0010] Still another object of the present invention is to provide an electro-acoustic transducer in which, when incorporated in a portable terminal device, the portable terminal device can be easily thinned. [0011] In the electro-acoustic transducer according to the present invention, an annular voice coil fixed to a central portion of a diaphragm is protruded to the back side of the diaphragm and disposed in the magnetic gap of a magnetic circuit. The first and second electro-acoustic conversion units are provided such that the back surfaces of the respective diaphragms face each other. 13-05-2019 3 [0012] Then, the diameter of the voice coil of the second electro-acoustic conversion unit is larger than the diameter of the voice coil of the first electro-acoustic conversion unit, and the voice coils are disposed concentrically, and on the first electro-acoustic conversion unit side A first space for allowing the displacement of the voice coil accompanying the vibration of the diaphragm and a second space for allowing the displacement of the voice coil accompanying the vibration of the diaphragm on the second electro-acoustic conversion unit side, It has a basic configuration that it is formed at a position where the voice coil of each of the first and second electro-acoustic conversion units is radially wrapped. Here, since the radial direction of the voice coil of the first electro-acoustic conversion unit and the voice coil of the second electro-acoustic conversion unit are arranged concentrically, the radial directions of both voice coils coincide with each other. [0013] With this configuration, the height dimension of the first space for allowing displacement of the voice coil due to the vibration of the diaphragm on the side of the first electro-acoustic transducer unit and the diaphragm on the side of the second electro-acoustic transducer unit The total length of the electro-acoustic transducer is not included in the total thickness of the electroacoustic transducer, and the electro-acoustic transducer is thin as much as the height dimension of the second space for allowing displacement of the voice coil accompanying vibration. Be Further, since the first and second electro-acoustic conversion units are provided with separate voice coils, it is possible to operate the first and second electro-acoustic conversion units independently. Therefore, it is possible to use the one electro-acoustic conversion unit to perform the transmission function and the other electro-acoustic conversion unit to perform the reception function. Therefore, by incorporating the electroacoustic transducer into a portable terminal device such as a portable telephone which is required to have a transmitting function and a receiving function, it becomes easy to thin the portable terminal device. 13-05-2019 4 [0014] In the present invention, each of the first and second electro-acoustic conversion units includes a magnet and a magnetic circuit formed by the yoke and the pole piece superimposed on the magnet with the magnet interposed therebetween, and the yoke and the pole The magnetic gap is formed by the gap space between the pieces, and the yoke of the first electroacoustic transducer unit and the yoke of the second electroacoustic transducer unit are formed by different portions of a single metal member. Is desirable. According to this, since the yoke of the first electro-acoustic conversion unit and the yoke of the second electro-acoustic conversion unit are shared by a single metal member, the number of parts is reduced accordingly, and cost reduction can be easily achieved. [0015] In the present invention, the single metal member has a tubular portion surrounding the magnet of the first electroacoustic transducer unit, and one end of the tubular portion overlaps the magnet of the first electroacoustic transducer unit. It is desirable that a part be connected in a row, and an overlapping portion of the second electro-acoustic transducer unit with the magnet be connected in series to the other end of the cylindrical part. [0016] Further, the overlapping portion of the metal member with respect to the magnet of the first electro-acoustic conversion unit is located inside the tubular portion, and the overlapping portion of the metal member with respect to the magnet of the second electro-acoustic transducer unit is outside the cylindrical portion. It is desirable to be located in [0017] Furthermore, the magnetic gap of the first electro-acoustic conversion unit is formed by a gap space between the other end of the cylindrical portion of the metal member and the pole piece of the first electro-acoustic conversion unit, and the second electro-acoustic conversion unit It is desirable that the above-mentioned magnetic gap is formed by the crevice space between the end of the cylindrical part of the above-mentioned metallic member, and the pole piece of the 2nd electroacoustic transducer unit. 13-05-2019 5 [0018] Furthermore, the magnet of the second electro-acoustic conversion unit is formed in a ring shape, and the ring-shaped magnet is disposed at a position surrounding the disc-shaped magnet of the first electro-acoustic conversion unit. It is also possible to adopt [0019] Furthermore, the shape of the diaphragm of the first electro-acoustic conversion unit may be different from the shape of the diaphragm of the second electro-acoustic conversion unit. It has the advantage of being easy to control. [0020] In the electro-acoustic transducer according to the present invention, in addition to the abovedescribed basic configuration, a single magnet material is shared by the magnet of the first electro-acoustic transducer unit and the magnet of the second electro-acoustic transducer unit, and the magnet It is also possible to adopt a configuration in which the material is disposed between the first space and the second space. According to this, since a single magnet material is shared by the magnet of the first electroacoustic conversion unit and the magnet of the second electro-acoustic conversion unit, the number of parts is reduced accordingly, and cost reduction can be easily achieved. [0021] In this case, the magnet material is formed in a ring shape, and has two metal members superimposed on the magnet material with the magnet material interposed therebetween, and an opening is formed in the central portion of one side metal member. The cylindrical portion formed in the center of the other side metal member is fitted with a gap in the opening, and the metal of the opening of the one side metal member and the metal of the other side The magnetic gap of the first acoustic conversion unit is formed by the gap space between the member and the cylindrical portion, and the cylindrical portion continuously connected to the outer peripheral portion of the one side metal member and the outer peripheral portion of the other side metal member It is possible to adopt a configuration in which the magnetic gap of the second acoustic conversion unit is formed by the space between them. 13-05-2019 6 [0022] In the electro-acoustic conversion unit according to the present invention, it is desirable that the first electro-acoustic unit and the second electro-acoustic unit be attached to a common housing for them, according to this, the number of housings is one Therefore, the number of parts is reduced accordingly, which makes it easier to reduce costs. [0023] The action exerted by the structure adopted in the present invention will also be clarified by the following description of the embodiment. [0024] 1 is a schematic plan view of an electro-acoustic transducer according to a first embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of a portion taken along the line II-II of FIG. The electro-acoustic transducer A includes two units of a first electro-acoustic transducer unit (hereinafter referred to as "first unit") 30 and a second electro-acoustic transducer unit (hereinafter referred to as "second unit") 50. . The first and second units 30 and 50 are attached to the common housing 70 in opposite directions to each other. That is, the first and second units 30 and 50 are attached to the housing 70 in a state in which the back surfaces of the diaphragms 34 and 54 separately provided in the first and second units 30 and 50 face each other. It is done. [0025] The first unit 30 includes a flat disk-shaped magnet 31 and a yoke 41 and a pole piece 32 which are superimposed on the magnet 31 with the magnet 31 interposed therebetween, and a magnetic circuit is formed by them. 13-05-2019 7 Then, an annular voice coil 35 fixed to the central portion of the diaphragm 34 is disposed in the magnetic gap 33 provided in the magnetic circuit so as to protrude to the back side of the circular diaphragm 34. The second unit 50 includes a flat ring-shaped magnet 51 disposed concentrically at a position surrounding the magnet 31 of the first unit 30, and a yoke 61 and a pole piece superimposed on the magnet 51 with the magnet 51 interposed therebetween. 52, which form a magnetic circuit. Then, in the magnetic gap 53 provided in the magnetic circuit, an annular voice coil 55 fixed to the central portion of the diaphragm 34 is disposed so as to protrude on the back side of the oval or elliptical diaphragm 54. ing. The diameter of the voice coil 55 of the second unit 50 is larger than the diameter of the voice coil 35 of the first unit 30, and the voice coils 35, 55 are disposed concentrically. [0026] In this embodiment, the yoke 41 of the first unit 30 and the yoke 61 of the second unit 50 are formed by different portions of a single metal member 90. This point will be specifically described with reference to a partially enlarged view of FIG. [0027] As can be seen in FIG. 2, the metal member 90 is formed in a disk shape having a recess in the center, and the cylindrical portion 91 forming the peripheral wall of the recess is the magnet of the first unit 30. The magnet 31 and the magnet 51 of the second unit 50 are disposed in an opposing space so as to surround the periphery of the magnet 31. Further, a flat circular bottom wall portion connected to one end 91 a of the cylindrical portion 91 is an overlapping portion 92 of the first unit 30 with the magnet 31, and the cylindrical portion 91 and the overlapping portion 92 Thus, the yoke 41 of the first unit 30 is formed. On the other hand, a flat ring-shaped wedge-shaped portion continuously connected to the other end 91 b of the cylindrical portion 91 is an overlapping portion 93 of the second unit 50 with respect to the magnet 51 and overlaps with the cylindrical portion 91. The yoke 51 of the second unit 50 is formed by the portion 93. 13-05-2019 8 Therefore, the overlapping portion 92 of the metal member 90 with respect to the magnet 41 of the first unit 30 is located inside the cylindrical portion 91, and the overlapping portion 93 of the metal member with respect to the magnet 61 of the second unit 50 is the cylindrical portion. It is located outside 91. The magnetic gap 33 of the first unit 30 is formed by the gap space between the other end of the cylindrical portion 91 of the metal member 90 and the pole piece 32 of the first unit 30. The magnetic gap 53 of the two units 50 is formed by a gap space between one end 91 a of the cylindrical portion 91 of the metal member 90 and the pole piece 52 of the second unit 50. [0028] The voice coil 35 of the first unit 30 is displaced along the axis along with the vibration of the diaphragm 34 of the first unit 30, and similarly, the voice coil 55 of the second unit 50 is of the second unit 50. As the diaphragm 54 vibrates, it is displaced along the axis along with it. Therefore, in this embodiment, the first space S10 for permitting the displacement of the voice coil 35 of the first unit 30 includes the magnet 41 of the first unit 30, the cylindrical portion 91 of the metal member 90, and the metal member 90. The second space S20 for allowing the displacement of the voice coil 55 of the second unit 50 is formed by an annular space surrounded by the outer peripheral portion of the overlapping portion 92 with respect to the magnet 41 of FIG. An annular space surrounded by the magnets 51 of the two units 50, the cylindrical portion 91 of the metal member 90, and the inner peripheral portion of the overlapping portion 93 of the metal member 90 with respect to the magnet 51 is formed. Therefore, the first space S10 and the second space 20 are positioned so as to wrap in the radial direction X of the voice coils 35, 55 of the first and second units 30, 50. In the enlarged view in FIG. 2, the wrap width dimension of the first space S10 and the second space 20 in the radial direction X of the voice coils 35, 55 of the first and second units 30, 50 is denoted by K It is indicated by. Since the voice coil 35 of the first unit 30 and the voice coil 55 of the second unit 50 are disposed concentrically, the radial directions X of both voice coils 35, 55 coincide with each other. [0029] The housing 70 is integrally formed of a synthetic resin excellent in electrical insulation, and has a cylindrical peripheral wall 72 at the center on one side and the outer periphery on the other side of the horizontally long flat base 71. It has 73. The wiring board 75 is disposed in an overlapping manner on one end side of the base portion 71 in the longitudinal direction, and the electrodes 76 and 77 provided on the wiring board 75 are provided with the first and second 13-05-2019 9 units 30 and 50, respectively. The lead terminals drawn from the voice coils 35 and 55 are soldered. Further, the outer peripheral portion of the metal member 90 forming the respective yokes 42 and 61 of the first and second units 30 and 50 is fixed to the inside of the peripheral wall portion 72 on one side of the base portion 71, The outer peripheral portion of the diaphragm 34 disposed inside the peripheral wall portion 72 is attached to the outer peripheral portion of the metal member 90, and further, the outer peripheral portion of the baffle 36 covering the diaphragm 34 is attached. 37 is a sound hole formed in the baffle 36. On the other hand, a baffle 56 covering the diaphragm 34 of the second unit 50 and the diaphragm 34 is disposed inside the peripheral wall portion 73 on the other surface side, and the outer peripheral portion thereof is attached. Reference numeral 57 denotes a sound hole formed in the baffle 56. [0030] According to the first embodiment described above, since the first and second units 30, 50 are provided with separate voice coils 35, 55, the first unit 30 and the second unit 50 operate independently. It is possible to Therefore, for example, the first unit 30 is used as a receiver, the second unit 50 is used as a speaker, and conversely, the first unit 30 is used as a speaker and the second unit 50 is used as a receiver. It is possible. [0031] Further, the first space S10 for allowing displacement of the voice coil 35 of the first unit 30 and the second space S20 for allowing displacement of the voice coil 55 of the second unit 50 have a cylindrical shape of the metal member 90. The first space S10 and the second space S20 are formed in the radial direction X of the voice coils 35 and 55 of the first and second units 30 and 50, respectively. It is positioned with a width dimension K wrapped. Therefore, a length (Y1 + Y2) obtained by combining the height dimension Y1 necessary for the first space S10 and the height dimension Y2 necessary for the second space S20 to secure the first space S10 and the second space S20. ) Is not required. In other words, in order to secure the first space S10 and the second space S20, the wrap width dimension K in the radial direction of each voice coil 35, 55 of both spaces S10, S20 and both protruding from the lap portion The total length [K + (Y1-K) + (Y2-K) = Y1 + (Y2-K)] of the spaces S10 and S20 may be combined. Therefore, the total length of the height dimension of the first space S10 and the height dimension of the second space S20 is not included in the overall thickness dimension of the electroacoustic transducer A, and accordingly the electroacoustic transducer A It becomes easy to thin. 13-05-2019 10 [0032] Furthermore, in the first embodiment, the yokes 41 and 61 of the first and second units 30 and 50 are different portions of the single metal member 90, that is, the yoke 41 of the first unit 30 is a cylindrical member of the metal member 90. Since the yoke 61 of the second unit 30 is formed by the cylindrical portion 91 and the overlapping portion 93 of the metal member 90, the first and second units 30, 50 are formed by the portion 91 and the overlapping portion 92. Not only is the number of parts reduced and cost is reduced as compared with the case where the yokes 41 and 61 are formed of separate members, but also because the single metal member 90 is shared by the respective yokes 41 and 61 There is also an advantage that the magnetic circuit efficiency is improved. [0033] FIG. 3 is a schematic plan view of an electro-acoustic transducer according to a second embodiment of the present invention, and FIG. 4 is a schematic cross-sectional view of a portion along line IV-IV in FIG. [0034] The second embodiment differs from the first embodiment only in that the diaphragm 50 of the second unit 50 is circular and the base 71 of the housing 70 is substantially circular. The other structure is the same as that of the first embodiment described in FIGS. 1 and 2. The operation is also the same as that of the first embodiment described with reference to FIGS. 1 and 2 except for matters relating to the acoustic characteristics described below. Therefore, in order to avoid duplication of explanation, the same numerals are given to the same or corresponding parts, and detailed explanation is omitted. [0035] In the first embodiment described above, the diaphragm 34 of the first unit 30 is circular, and the diaphragm 54 of the second unit 50 is oval or elliptical. The diaphragm 34 of one unit 30 and the diaphragm 54 of the second unit 50 are formed in a circular shape. For this reason, in any of the electro-acoustic transducer A of the first embodiment and the second embodiment, the 13-05-2019 11 acoustic characteristics of the units 30 and 50 can be easily controlled individually. For example, in the first embodiment, the first unit 30 is used as a receiver, and the diaphragm 34 is circular with a diameter of 10 mm, while the second unit 50 is used as a speaker, and the diaphragm 54 is elliptical. This makes it easier to control the acoustic characteristics of each unit 30, 50 individually. In the second embodiment, the first unit 30 is used as a receiver, and the diaphragm 34 is formed in a circular shape with a diameter of 10 mm, whereas the second unit 50 is used as a speaker, and the diaphragm 54 is formed with a circular shape with a diameter of 16 mm. By setting it, it becomes easy to control the acoustic characteristic of each unit 30, 50 separately. [0036] FIG. 5 is a schematic plan view of an electro-acoustic transducer according to a third embodiment of the present invention, and FIG. 6 is a schematic cross-sectional view of a portion along line VIVI in FIG. [0037] In the third embodiment, the electroacoustic transducer A has a first unit 30 and a second unit 50, and the diaphragms 34 and 54 separately provided in the first and second units 30 and 50, respectively. The first and second units 30, 50 are attached to the common casing 70 in a state in which the back surfaces face each other, similarly to the first embodiment and the second embodiment described above. is there. [0038] In the third embodiment, a single magnet member 80 is shared by the magnet 31 of the first unit 30 and the magnet 51 of the second unit 50. The magnet member 80 is formed in a flat ring shape (annular shape), and has two metal members 81 and 86 superimposed on the magnet member 80 with the magnet member 80 interposed therebetween. A circular opening 82 is formed at the central portion of the one side metal member 81. On the other hand, a cylindrical portion 87 is formed in the central portion of the metal member 86 on the other side, and the cylindrical portion 87 is fitted in the opening 82 with a gap. The magnetic circuit of the first unit 30 is formed by the magnet member 80 and the metal members 81 and 13-05-2019 12 86 on one side and the other side, and the magnetic gap 33 of the magnetic circuit is the opening 82 of the metal member 81 on one side. A clearance space is formed between the lip 82 a and the cylindrical portion 87 of the metal member 86 on the other side. The magnet member 80 and the metal members 81 and 86 on one side and the other side also form a magnetic circuit of the second unit 50, and the magnetic gap 53 of the magnetic circuit is the one of the metal member 81 on one side. A clearance space is formed between the cylindrical portion 83 continuously provided on the outer peripheral portion and the outer peripheral portion 86 a of the metal member 86 on the other side. [0039] The voice coil 35 projected on the back side of the diaphragm 34 of the first unit 30 is disposed in the magnetic gap 33 of the first unit 30, and the voice coil 55 projected on the back side of the diaphragm 54 of the second unit 50. Are disposed in the magnetic gap 53 of the second unit 50. The diameter of the voice coil 55 of the second unit 50 is larger than the diameter of the voice coil 35 of the first unit 30, and the voice coils 35, 55 are concentrically arranged in the first embodiment. The same as in the case of. [0040] The voice coil 35 of the first unit 30 is displaced along the axis along with the vibration of the diaphragm 34 of the first unit 30, and similarly, the voice coil 55 of the second unit 50 is of the second unit 50. As the diaphragm 54 vibrates, it is displaced along the axis along with it. Therefore, in this embodiment, the first space S10 for permitting the displacement of the voice coil 35 of the first unit 30 includes the magnet member 80 and the cylindrical portion 87 of the other side metal member 86 and the other side metal member 86. Of the second unit 50 while allowing the displacement of the voice coil 55 of the second unit 50 to be formed by the annular space surrounded by the flat wedge portion 88 overlapping the magnet material 80 of FIG. An annular space surrounded by the space S20 by the magnet member 80, the cylindrical portion 83 of the metal member 81 on one side, and the flat wedge portion 84 overlapping the magnet member 80 on the metal member 86 on one side. It is formed by For this reason, the magnet material 80 is disposed between the first space S10 and the second space S20, and the first space S10 and the second space 20 correspond to the voices of the first and second units 30, 50. The coils 35 and 55 are positioned so as to wrap in the radial direction X. [0041] 13-05-2019 13 The housing 70 is integrally formed of a synthetic resin excellent in electrical insulation, and has a cylindrical peripheral wall 72 at the center on one side and the outer periphery on the other side of the horizontally long flat base 71. It has 73. The wiring board 75 is disposed in an overlapping manner on one end side of the base portion 71 in the longitudinal direction, and the electrodes 76 and 77 provided on the wiring board 75 are provided with the first and second units 30 and 50, respectively. The lead terminals drawn from the voice coils 35 and 55 are soldered. Further, the cylindrical portion 83 of the metal member 81 on one side is fixed to the inside of the peripheral wall 72 on one side of the base portion 71, and is disposed on the inside of the peripheral wall 72 on the outer peripheral portion of the metal member 81. The outer peripheral portion of the diaphragm 34 is attached, and further, the outer peripheral portion of the baffle 36 covering the diaphragm 34 is attached. On the other hand, a baffle 56 covering the diaphragm 34 of the second unit 50 and the diaphragm 34 is disposed inside the peripheral wall portion 73 on the other surface side, and the outer peripheral portion thereof is attached. [0042] In the third embodiment, the wedge portion 88 and the tubular portion 87 of the metal member 86 on the other side function as the yoke of the first unit 30, and the wedge portion 84 of the metal member 81 on one side is the first. It functions as a pole piece of unit 30. The wedge portion 84 and the tubular portion 83 of the metal member 81 on one side function as the yoke of the second unit 50, and the wedge portion 88 of the metal member 86 on the other side is the pole piece of the second unit 50. Plays the function of [0043] Also in the third embodiment described above, since the first and second units 30, 50 are provided with separate voice coils 35, 55, the first unit 30 and the second unit 50 operate independently. It is possible to Therefore, for example, the first unit 30 is used as a receiver, the second unit 50 is used as a speaker, and conversely, the first unit 30 is used as a speaker and the second unit 50 is used as a receiver. It is possible. [0044] 13-05-2019 14 Further, a first space S10 for allowing displacement of the voice coil 35 of the first unit 30 and a second space S20 for allowing displacement of the voice coil 55 of the second unit 50 are ringshaped magnet members 80. Of the first space S10 and the second space S20 in the radial direction X of the voice coils 35 and 55 of the first and second units 30 and 50, respectively. positioned. Therefore, a length (Y1 + Y2) obtained by combining the height dimension Y1 necessary for the first space S10 and the height dimension Y2 necessary for the second space S20 to secure the first space S10 and the second space S20. ) Is not required, and the combined length of the height dimension Y1 of the first space S10 and the height dimension Y2 of the second space S20 is not included in the overall thickness dimension of the electroacoustic transducer A, The electroacoustic transducer A can be easily thinned accordingly. This point is the same as that described in the first embodiment. [0045] Furthermore, in the third embodiment, since the magnet material 80 is shared by the magnets of the first and second units 30 and 50, the magnets of the first and second units 30 and 50 can be separate magnet materials. The number of parts can be reduced and cost can be reduced as compared with the case of forming by the above. [0046] In FIG. 5 and FIG. 6, in order to simplify the description, the same reference numerals are given to the same or corresponding parts as the parts shown in FIG. 1 and FIG. [0047] FIG. 7 schematically shows an internal structure when the electroacoustic transducer A described in the first to third embodiments is incorporated into a portable telephone used as a portable terminal. In the figure, 21 is a flat hollow case, and the electro-acoustic transducer A, the liquid crystal display (LCD) 24 and the like are incorporated in the case 21 and provided in the electro-acoustic transducer A. A first unit 30 is disposed facing the sound hole 26 of the inner side wall 25 of the case 21, and a second unit 50 is disposed facing the sound hole 29 of the outer side wall 28 of the case 21. Then, the first unit 30 is used as a receiver, and the second unit 50 is used as a speaker. 13-05-2019 15 [0048] In this mobile phone, the electroacoustic transducer A provided inside the case 21 integrally includes the first unit 30 as a receiver and the second unit 50 as a speaker, and further, the electroacoustic transducer A However, since the thickness is thin as described in the first to third embodiments, it is easy to shorten the overall thickness dimension T1 of the case 21 to achieve the thinning. [0049] In FIG. 7, the same or corresponding parts as those in FIG. 9 are indicated by the same reference numerals to simplify the description. [0050] As described above, according to the present invention, two diaphragms are provided, and the two diaphragms can be operated independently to exhibit the transmitting function and the receiving function. However, it is possible to provide an electroacoustic transducer that can be easily thinned by shortening the overall thickness dimension. In addition, it is possible to reduce the cost by reducing the number of parts, and it is possible to provide an electroacoustic transducer that can easily reduce the thickness of the portable terminal device when it is incorporated into the portable terminal device. Become. 13-05-2019 16
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