WO2011111968A2 - Speaker - Google Patents

Abstract

The present invention relates to a speaker wherein, in configuring the magnetic circuit of the speaker, the vertically-oriented polarity arrangement of the prior art is not adhered to in that the polarity of the magnet is formed with a horizontal orientation, and a vibration system is formed inside the magnetic circuit formed with the horizontal orientation. Consequently, because the magnetic circuit surrounds the vibration system, it is possible to produce a speaker that has only the height of the magnetic circuit, which contrasts with speakers of the prior art which have been formed to a height comprising the sum of the thicknesses of the magnetic circuit and the vibration system. Also, the acoustic characteristics of the speaker can be improved because the height of the speaker can be reduced even if the volume of the magnet is large.

Description

speaker

TECHNICAL FIELD The present invention relates to a speaker, and more particularly, to a speaker having excellent performance while having a significantly low height.

In general, speakers are devices that convert electrical signals into sounds that we can hear. Meanwhile, among the speakers, the micro speaker refers to a speaker suitable for mounting in a small electronic device or a mobile communication terminal.

At present, electronic devices are becoming smaller and lighter. Therefore, the speakers applied to electronic devices also need to be smaller, lighter and better performance.

1 and 2 are cross-sectional views showing a single magnet speaker according to the prior art. As shown in FIG. 1, in the speaker according to the related art, the frame 111 forms the outer shape of the speaker 120. A yoke 104 is provided inside the frame 111 to provide a passage path for the magnetic flux generated by the magnet 101. The yoke 104 is composed of a cylindrical bottom plate 102 and a disc shaped top plate 103 with a closed bottom. A disc shaped magnet 101 is placed between the bottom plate 102 and the top plate 103. On the other hand, the magnetic flux generated by the magnet 101 is guided to the yoke 104 and meets the discontinuous point of the yoke 104, which is called a magnetic gap.

As shown in FIG. 2, the magnet 101, the yoke 104 and the magnetic gap form a magnetic circuit. Magnetic circuits are devices that provide the magnetic fields needed by speakers to convert electrical signals into sound.

On the other hand, a voice coil 105 is located in the magnetic gap. The voice coil 105 is connected to a diaphragm 106. When the voice coil 105 moves up and down in accordance with the electrical signal applied to the voice coil 105, this movement is transmitted to the diaphragm 106, and the diaphragm 106 vibrates, whereby the electrical signal is converted into sound. As shown in FIG. 1, the diaphragm 106 has a central dome and an edge rib shape, and a voice coil 105 is connected to a boundary between two domes. The reason why the diaphragm 106 has a double dome shape is to control the vibration range while smoothing the vibration of the diaphragm 106.

A lead wire 107 is connected to the voice coil 105 to apply an electrical signal. The leadwire 107 is generally bonded along the surface of the diaphragm 106 and is connected to the terminal PCB 108 through a hole formed in the frame 111.

As shown in FIG. 2, the diaphragm 106 and the voice coil 105 form a vibrometer 132.

The through cap 109 is covered above the diaphragm 106. The through cap 109 is for protecting devices inside the speaker, including the diaphragm 106. In addition, in order for the sound generated by the diaphragm 106 to be well transmitted to the outside of the speaker, the through cap 109 is formed with a plurality of through holes 110. Meanwhile, a plurality of heat dissipation openings 112 are formed in the frame 111 so that heat generated inside the speaker is discharged outward.

The speaker according to the prior art operates as follows. When an electrical signal is applied to the voice coil 105 via the terminal PCB 108 and the lead wire 107, the voice coil 105 located in the magnetic gap moves in a direction perpendicular to the magnetic field by the Fleming law. This movement is transmitted to the diaphragm 106. The motion transmitted to the diaphragm 106 vibrates the diaphragm 106, whereby the electrical signal is converted into sound.

The speaker of the prior art according to FIGS. 1 and 2 has the following problems. First, in the speaker according to the prior art, since the magnetic circuit 131 and the vibrometer 132 are vertically layered, there is a problem that the overall height of the speaker increases. That is, the overall height of the speaker was determined by adding the thickness of the magnetic circuit and the thickness of the vibration system.

Therefore, in order to make the thickness of the speaker thinner, the thickness of the magnet 101 has to be reduced. However, when the thickness of the magnet 101 is reduced, the magnetic flux density of the magnetic gap is reduced, resulting in a lower sound pressure of the speaker.

In addition, due to the thickness of the speaker 120, the separate assembly in the electronic module (PCB) PCB board not only reduces the efficiency of the manufacturing process, but also increases the assembly time due to many components, which eventually has a problem that the manufacturing cost increases. .

3 is a cross-sectional view showing a double magnet speaker according to the prior art. The speaker shown in FIG. 3 has a disk shaped first magnet 141 and a ring-shaped second magnet 142 sharing a center with the first magnet.

The first magnet 141 and the second magnet 142 are provided on one bottom plate 143. Meanwhile, the first magnet is covered with the first top plate 144, and the second magnet is covered with the second top plate 145. A magnetic gap is formed between the first top plate 144 and the second top plate 145. In addition, the bottom plate 143, the first top plate 144, and the second top plate 145 form a yoke 146 that provides a passage path for the magnetic flux.

Since the double magnet speaker according to FIG. 3 also has a magnetic circuit and a vibrometer, the thickness of the first magnet 141 and the second magnet 142 can be reduced to reduce the thickness of the entire speaker. Therefore, as with a single magnet speaker, not only the sound pressure is lowered, but also the manufacturing cost increases due to the complicated structure.

4 is a cross-sectional view showing a speaker according to the prior art applied to a navigation and a portable game machine. The speaker shown in FIG. 4 is also a speaker of the same method as FIG. 1. However, in order to improve productivity, the bottom plate 151 was used as a frame. In addition, in order to reduce the thickness of the speaker itself, the speaker illustrated in FIG. 4 has a thin vibration system.

However, in the speaker shown in FIG. 4, the voice coil 152 deviates much from the magnetic field, causing loss of frequency band. That is, there is a problem in that the lowest reproduction limit frequency f0 becomes high.

In addition, a thick voice coil 152 should be used to produce a high output, and the outer diameter of the voice coil 152 is small, so that the winding width is increased, and the X-MAX value when the voice coil 152 is reciprocated up and down (at rated output). Due to the vertical movement width of the coil (mm), the height of the magnetic circuit is increased. In addition, there is a problem of lack of clarity, resolution and sound pressure of the voice tone due to the weakening of the magnetic force of the magnetic circuit.

5 is a cross-sectional view showing a magnetic and magnetic magnetic circuits according to the prior art. 5 (a) is a cross-sectional view showing a conventional magnetic magnetic circuit configuration, (b) is a cross-sectional view showing a conventional magnetic magnetic circuit configuration.

In FIG. 5A, since the magnet 161 is inside the yoke 164, this is called a magnetic magnetic circuit. Here, the yoke 164 includes a bottom plate 162 and a top plate 163, and the arrow direction indicates a passage path of the magnetic flux formed by the magnet 161.

5B is referred to as an external magnetic circuit because the magnet 171 has a structure outside the pole piece 175 connected to the bottom plate 172. The arrow direction shown in (b) of FIG. 5 indicates a passage path of the magnetic flux formed by the magnet 171.

As described above, the speaker according to the prior art has a problem in that the height of the speaker is increased by stacking a bottom plate, a magnet, and a top plate to form a magnetic circuit, and by constructing a vibrometer thereon.

The present invention is to solve the problems of the prior art as described above, it is an object of the present invention to provide a speaker that improves the acoustic characteristics while significantly reducing the height of the speaker.

In order to achieve the above object, the present invention, in the configuration of the magnetic circuit of the speaker, unlike the polarity arrangement in the vertical direction of the prior art, the magnetic circuit formed in the horizontal direction, forming the polarity of the magnet in the horizontal direction A vibrometer is formed inside.

The micro speaker according to the present invention has the following effects.

First, it can increase the magnetic force to provide high output sound pressure.

Second, by reducing the height of the speaker as much as possible, it is possible to reduce the size of the electronic device equipped with the speaker.

Third, since the voice coil diameter is large, a wire thicker than the conventional voice coil thickness can be used, and thus a high input and high output speaker can be manufactured.

Fourth, the number of speaker parts can be reduced to simplify the assembly work of the micro-speakers, and the production cost can be reduced by automating the production.

Fifth, since the through portion is formed on the bottom surface side, heat generated in the voice coil can be immediately released, and durability can be improved.

Seventh, the sound pressure can be increased, but the strong diaphragm can be used to lower f0.

Eighth, it is possible to assemble together with the electronic PCB module of a small portable device manufacturer has the effect of improving productivity.

1 and 2 are cross-sectional views showing a single magnet speaker according to the prior art.

3 is a cross-sectional view showing a double magnet speaker according to the prior art.

4 is a cross-sectional view showing a speaker according to the prior art applied to a navigation and a portable game machine.

5 is a cross-sectional view showing a magnetic and magnetic magnetic circuits according to the prior art.

6 is a cross-sectional view of an embodiment of a magnetic circuit of a speaker according to the present invention.

7 is a sectional view showing a first embodiment of a speaker according to the present invention.

8 is a sectional view showing a second embodiment of a speaker according to the present invention.

9 is a sectional view showing a third embodiment of a speaker according to the present invention.

10 is an exploded perspective view showing a first embodiment of a speaker according to the present invention.

11 is an exploded perspective view showing a third embodiment of a speaker according to the present invention.

12 is a graph comparing the performance of the speaker according to the first embodiment of the present invention with the performance of the speaker according to the prior art.

13 is a graph comparing the performance of the speaker according to the third embodiment of the present invention with the performance of the speaker according to the prior art.

The speaker according to the present invention includes a magnetic circuit and a vibrometer, wherein the magnetic circuit has a ring shape, based on the center of the ring, has a first polarity on the outer surface, and the first surface on the inner surface. A magnet having a second polarity opposite to the polarity and a yoke that provides a passage path for the magnetic flux generated from the magnet.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

6 is a cross-sectional view of an embodiment of a magnetic circuit of a speaker according to the present invention. In the magnetic circuit of FIG. 6, the N pole and the S pole of the magnet are formed horizontally. In the magnetic circuit of the speaker according to the prior art, as shown in Fig. 5, the magnet is formed with the N pole and the S pole vertically, the magnetic flux is formed horizontally only in the magnetic gap. However, in the magnetic circuit according to the present invention, the N pole and the S pole are formed horizontally, and the magnetic flux is formed horizontally even in the magnetic gap.

Figure 6 (a) shows an embodiment having two plates in the magnetic circuit of the speaker according to the present invention. Referring to FIG. 6 (a), the magnet 501 according to the present embodiment has a ring shape and has a step from the outside to the inside. In addition, the polarity of the magnet 501 is formed as the S pole on the inside and the N pole on the outside. That is, the N pole and the S pole are formed horizontally. On the other hand, it is obvious that the N pole is located on the inner side, it may be formed horizontally so that the S pole on the outside.

As shown in FIG. 6A, when the N pole is located outside the magnet 501, the magnetic flux starts at the N pole, and the first plate 502, the magnetic gap 505, and the second plate ( Pass 503 to the S pole of the magnet 501. The first plate 502 and the second plate 503 serve as yokes 504 that provide a passage path for the magnetic flux. In this case, the magnetic circuit may be configured such that the magnet 501 is in close contact with the first plate 501. However, as shown in FIG. 6A, the magnetic circuit may be configured such that the magnet 501 is spaced apart from the first plate 501 by a predetermined distance.

Figure 6 (b) shows an embodiment having one plate in the magnetic circuit of the speaker according to the present invention. Referring to FIG. 6 (b), the magnet 601 according to the present embodiment has a ring shape and has a step from the outside to the inside. In addition, the polarity of the magnet 601 is formed as the S pole on the inside and the N pole on the outside. That is, the N pole and the S pole are formed horizontally. On the other hand, it is obvious that the N pole is located on the inner side, it may be formed horizontally so that the S pole on the outside.

As shown in FIG. 6 (b), when the N pole is located outside the magnet 601, the magnetic flux starts at the N pole and passes through the yoke 602 and the magnetic gap 605 to the magnet 601. Head to the S pole. Yoke 602 provides a path for passage of magnetic flux. At this time, as shown in Figure 6 (b), the magnetic circuit may be configured such that the magnet 601 is in close contact with the yoke 602, or may be configured to be spaced apart from the yoke 602 by a predetermined distance. .

7 is a sectional view showing a first embodiment of a speaker according to the present invention. This embodiment relates to a speaker to which a magnetic circuit of the type described in Fig. 6A is applied. The magnetic circuit of the speaker according to the present embodiment includes a magnet 701 having horizontally formed N poles and S poles, a first plate 702, a second plate 703, and a first plate 702 and a second plate ( And a magnetic gap 705 formed between 703.

The magnet 701 is preferably a ring shape having a step from the outside to the inside. In this case, the ring shape includes not only a circular ring but also a ring shape having a square or ellipse shape.

For example, in the case where the outside of the magnet 701 forms the N pole, the magnetic flux generated in the magnet 701 passes through the first plate 702 and passes through the magnetic gap 705 and the second plate 703. It leads to the S pole formed inside the magnet 701. Thus, the first plate 702 and the second plate 703 perform the function of a yoke 704 to provide a passage path for the magnetic flux.

On the other hand, the vibration system of the speaker according to the present embodiment is composed of a voice coil 706 and a diaphragm 707 located in the magnetic gap 705. The voice coil 706 is connected to the diaphragm 707 and the edge part 708, the diaphragm 707 is preferably a double dome shape having a dome shape at the center and a lip shape at the edge. The edge portion 708 not only supports the voice coil 706, but also facilitates the movement of the diaphragm 707 and performs a function of controlling the vibration of the diaphragm not to exceed a predetermined range. The voice coil 706 is connected to the lead wire 709 to receive an electrical signal, the lead wire 709 is connected to the terminal PCB 710. The external amplifier signal is delivered to the speaker via the terminal PCB 710.

The through cap 711 is covered above the diaphragm 707. The through cap 711 is for protecting devices inside the speaker, including the diaphragm 707. In addition, in order for the sound generated by the diaphragm 707 to be transmitted to the outside of the speaker, the through cap 711 forms a plurality of through holes. The bottom portion 712 is attached to the bottom of the first plate 702, and serves to filter foreign matter from entering the speaker, as well as to release heat inside the speaker to the outside.

As described above, the speaker according to the present invention, since the height of the ring-shaped magnet (or the height of the magnetic circuit) determines the height of the speaker, provides a speaker that is significantly reduced in thickness compared to the prior art. That is, according to the speaker of the prior art, since the vibration system is formed above the magnetic circuit, the thickness of the speaker is the sum of the height of the magnetic circuit and the height of the vibration system. However, according to the present invention, since the vibrometer is surrounded by the magnetic circuit, the thickness of the speaker is determined by the height of the magnetic circuit. Therefore, the thickness of the speaker is reduced by the height of the vibration system. Furthermore, the strength of the magnetic field of the magnetic circuit is dependent on the volume of the magnet, the speaker according to the present invention can maintain the volume while reducing the thickness of the magnet, since the magnet is made of the outer diameter of the speaker, reducing the height of the magnetic circuit It becomes possible.

In addition, as the yoke functions as a frame forming the outer shape of the speaker, a separate frame is omitted, thereby increasing the size of the magnetic circuit.

Table 1 compares the magnetic flux density formed in the yoke in the magnetic circuit of the prior art with the magnetic flux density formed in the yoke of the speaker according to the first embodiment of the present invention.

Table 1 polarity Gaussian maximum Prior art N pole 500 S pole 1000 The present invention N pole 2200 S pole 2500

Referring to Table 1, it can be seen that the magnetic circuit according to the first embodiment of the present invention has twice the magnetic flux density as compared to the magnetic circuit according to the prior art.

In the speaker magnetic circuit section, when the mass of the vibration system (weight of the voice coil + weight of the diaphragm) is constant, it can be seen that the speaker according to the present invention can further improve the sound pressure based on the strength of a very large magnetic field. .

Table 2 compares the performance of the speaker according to the prior art and the speaker according to the first embodiment of the present invention.

TABLE 2 Diaphragm thickness Coil thickness Impedance (Ω) Sound pressure (db) Prior art 10 micron φ40 micron 7.4 90 Invention 20 micron φ60 micron 6.8 96

Referring to Table 2, it can be seen that the thickness of the diaphragm of the speaker according to the prior art and the thickness of the diaphragm according to the first embodiment of the present invention are different from each other by 10 microns, but there is a significant difference in sound pressure. .

In addition, since the voice coil according to the prior art has a wire diameter of φ 40 microns, it is generally not able to produce a high output, but in the first embodiment of the present invention, it is possible to further increase the sound pressure by using a thicker coil wire. It is shown.

At this time, it is preferable that the size of the magnetic gap is 0.23 mm in the gap between the N pole (or S pole) and the inner diameter coil. In addition, the gap between the S pole (or N pole) and the outer diameter coil is also preferably set to 0.23 mm.

8 is a sectional view showing a second embodiment of a speaker according to the present invention. This embodiment relates to a speaker to which a magnetic circuit of the type described in FIG. 6 (b) is applied. The magnetic circuit of the speaker according to the present embodiment includes a magnet 801, a yoke 804, and a magnetic gap 805 formed between the yoke 804 and the magnet 801 in which the N pole and the S pole are horizontally formed. Is done. The magnet 801 is preferably a ring shape having a step from the outside to the inside. In this case, the ring shape includes not only a circular ring but also a ring shape having a square or ellipse shape.

For example, in the case where the outside of the magnet 801 forms the N pole, the magnetic flux generated in the magnet 801 passes through the yoke 804, passes through the magnetic gap 805, and is formed inside the magnet 801. It leads to the pole. Thus, yoke 804 provides a path for passage of magnetic flux.

On the other hand, the vibration system of the speaker according to the present embodiment is composed of a voice coil 806 and a diaphragm 807 located in the magnetic gap 805. The voice coil 806 is connected to the diaphragm 807 and the edge portion 808, the diaphragm 807 is preferably a double dome shape having a dome shape at the center and a lip shape at the edge. The edge portion 808 not only supports the voice coil 806, but also facilitates the movement of the diaphragm 807, and performs a function of controlling the vibration of the diaphragm not to exceed a predetermined range. The voice coil 806 is connected to the lead wire 809 to receive an electrical signal, the lead wire 809 is connected to the terminal PCB 810. The external amplifier signal is transmitted to the speaker through the terminal PCB (810).

The through cap 811 is covered above the diaphragm 807. The through cap 811 is for protecting devices inside the speaker, including the diaphragm 807. In addition, in order for the sound generated by the diaphragm 807 to be well transmitted to the outside of the speaker, it is preferable to form a plurality of through holes in the through cap 811. The bottom portion 812 together with the yoke 804 forms the bottom surface of the speaker. The bottom portion 812 not only serves to filter foreign matter from entering the speaker, but also discharges heat inside the speaker to the outside.

9 is a sectional view showing a third embodiment of a speaker according to the present invention. This embodiment relates to a speaker to which the magnetic circuit in which the form described in Fig. 6A is modified is applied.

The magnetic circuit of the speaker according to the present embodiment includes a magnet 901 in which N poles and S poles are formed horizontally, a first plate 902, a second plate 903, and a first plate 902 and a second plate ( And a magnetic gap 905 formed between 903. The magnet 901 is preferably ring-shaped. In this case, the ring shape includes not only a circular ring but also a ring shape having a square or ellipse shape.

For example, when the outside of the magnet 901 forms an N pole, the magnetic flux generated in the magnet 901 passes through the first plate 902 and passes through the magnetic gap 905 and the second plate 903. It leads to the S pole formed inside the magnet 901. Thus, the first plate 902 and the second plate 903 perform the function of a yoke 904 to provide a passage path for the magnetic flux.

On the other hand, the vibration system of the speaker according to the present embodiment is composed of a voice coil 906, a bobbin 911 and a diaphragm 907 located in the magnetic gap 905. The voice coil 906 is wound around the bobbin 911, which is connected to the diaphragm 907 and the edge portion 908. The diaphragm 907 preferably has a triple rib shape. The edge portion 908 not only supports the voice coil 906, but also facilitates the movement of the diaphragm 907 and performs a function of controlling the vibration of the diaphragm not to exceed a predetermined range. The voice coil 906 is connected to the lead wire 909 to receive an electrical signal, the lead wire 909 is connected to the terminal PCB 910. The external amplifier signal is transmitted to the speaker through the terminal PCB (910). Meanwhile, the bottom portion 912 is attached to the bottom surface of the first plate 902.

The speaker according to the present embodiment has omitted the through-cap so as to be mounted in the plastic injection molding of the small electronic device. According to this embodiment, since the strength of the magnetic field of the magnetic circuit is enhanced, it is preferable to lower the f0 by making the thickness of the diaphragm 40 microns. According to the configuration as described above, the speaker according to the present embodiment has the advantage that can extend the middle voice band of the audio frequency.

10 is an exploded perspective view showing a first embodiment of a speaker according to the present invention. The speaker shown in FIG. 10 corresponds to a case where the magnet 701 has a substantially rectangular ring shape.

As shown in FIG. 10, the magnet 701 is bound inside the first plate 702, and the second plate 703 having a rectangular ring shape is bound inside the magnet 701. Meanwhile, the voice coil 706 is located in a magnetic gap, which is a gap between the first plate 702 and the second plate 703, and the inside of the voice coil 706 is connected to the diaphragm 707 having a double dome shape. The outer side of the voice coil 706 is connected to an edge portion constituting the outer side of the diaphragm.

Meanwhile, a terminal PCB 710 for applying an electrical signal is located inside the first plate 702, and upper and lower ends of the speaker are covered with the through cap 711 and the bottom 712.

Speakers according to embodiments of the present invention can be applied to a speaker of various uses, it is particularly preferable to apply to a micro speaker.

11 is an exploded perspective view showing a third embodiment of a speaker according to the present invention. The speaker shown in FIG. 11 corresponds to the case where the magnet 901 has a circular ring shape.

As shown in FIG. 11, the magnet 901 is bound inside the first plate 902, and the second plate 903 having a circular ring shape is bound inside the magnet 901. The voice coil 906 is wound around the bobbin 911, and the bobbin 911 on which the voice coil 906 is wound is located in a magnetic gap, which is a gap between the first plate 902 and the second plate 903. On the other hand, the bobbin 911 is connected to the diaphragm 907 having a lip shape on the inside, and is connected to the edge portion forming the outside of the diaphragm 907 on the outside.

On the other hand, the terminal PCB 910 for applying an electrical signal is located inside the first plate 902, the lower end of the speaker is covered with a bottom portion 912.

12 is a graph comparing the performance of the speaker according to the first embodiment of the present invention with the performance of the speaker according to the prior art. This graph shows the sound pressure and frequency according to the 3cc rear open type using ARTA measuring instruments and measuring microphones.

12, it can be seen that the speaker according to the first embodiment of the present invention has a flatter characteristic at a wider frequency than the speaker according to the prior art. In addition, it can be seen that in the case of the mid and low frequencies, which are human voice bands, the sound pressure is remarkably high. Therefore, when the present invention is applied to a mobile communication terminal or the like, it can be seen that the call sound can be provided with high sound quality such as earphone sound.

13 is a graph comparing the performance of the speaker according to the third embodiment of the present invention with the performance of the speaker according to the prior art. This graph shows the sound pressure and frequency at 1m / 1w / 2.83v on an 8 kHz basis using an LMS measuring instrument and a measuring microphone.

Referring to FIG. 13, it can be seen that the speaker according to the third embodiment of the present invention has superior f0 to 200 to 300 Hz and a sound pressure of 4 dB or more as compared with the speaker of the related art.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the spirit of the present invention for those of ordinary skill in the art to which the present invention pertains, as described above and the accompanying examples. It is not limited by the drawings.

The present invention can be applied to various speakers.

Claims (12)

Including magnetic circuits and vibrometers, The magnetic circuit, A magnet having a ring shape and having a first polarity on an outer side surface and a second polarity opposite to the first polarity on an inner side surface based on the center of the ring; And Yoke to provide a passage path for the magnetic flux generated from the magnet Speaker comprising a. The method of claim 1, The yoke, A first plate providing a passage path for magnetic flux corresponding to the first polarity; And A second plate providing a passage path for the magnetic flux corresponding to the second polarity Speaker comprising a. The method of claim 2, And the first plate and the second plate are spaced apart from each other to form a magnetic gap. The method of claim 1, The yoke, And a passage path for magnetic flux corresponding to the first polarity. The method of claim 4, wherein The yoke is spaced apart from the magnet to form a magnetic gap. The method of claim 1, The vibration system is a speaker, characterized in that formed on the inside of the magnetic circuit, based on the center of the ring. The method of claim 6, The height of the vibration system is a speaker, characterized in that lower than the height of the magnet. The method of claim 1, The vibrometer, A conductive wire to which an electric signal is applied, the voice coil being located in a magnetic field formed according to the magnetic circuit and performing mechanical movement according to the electric signal and the magnetic field; And A diaphragm connected to the voice coil and converting mechanical movement of the voice coil into sound; Speaker comprising a. The method of claim 8, The magnet, characterized in that having a step on the inner side with respect to the center of the ring. The method of claim 9, The vibrometer, One side is connected to the step of the magnet, the other side speaker further comprises an edge portion connected to the voice coil. The method of claim 1, The ring shape is, A speaker comprising a circular ring shape. The method of claim 1, The ring shape is, A speaker comprising a rectangular ring shape.

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