KR101460431B1 - Electroacoustic transducer having electromagnetic damper - Google Patents

Abstract

The present invention relates to an acoustic transducing organ having an electromagnetic damping function for suppressing vibration of a diaphragm by electromagnetic force of a coil member, comprising a frame, a diaphragm fixed to the frame, a pair of magnets provided inside the frame, And a coil member fixed to the diaphragm, wherein the magnet is installed in parallel to form one gap therebetween, and an upper plate is provided on the upper surface and a lower plate is provided on the lower surface Constituting a magnetic circuit; The coil member may include two voice coils vertically installed between the air gaps to vibrate the diaphragm up and down and two damping coils horizontally installed on the gap to vibrate in a direction opposite to the voice coil, And the damping coil performs an electromagnetic damping function to suppress the vibration of the diaphragm when the diaphragm vibrates up and down by the voice coil.

Description

TECHNICAL FIELD [0001] The present invention relates to an electroacoustic transducer having an electromagnetic damping function,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electroacoustic transducer (electroacoustic transducer), and more particularly to an electroacoustic transducer having an electromagnetic damping function for suppressing vibration of a diaphragm by an electromagnetic force of a coil member.

2. Description of the Related Art In general, portable communication terminals such as a cellular phone, a PDA, a notebook, a hearing aid, etc. are equipped with an electroacoustic transducer to enable sound output. Acoustic transducer is a speaker and receiver capable of outputting sound and sound. Micro speaker, and the like, and a vibration generating device that outputs sound in a three-dimensional manner by generating vibration power as well as sound.

Especially, the micro speaker is a device that converts the input frequency signal into sound and outputs it. When the electric conductor is in the magnetic field, it receives the electric energy by the coil existing between the gaps by the Fleming's left- To mechanical energy.

Therefore, when a current signal including several frequencies is applied to a coil, the coil generates mechanical energy according to the magnitude of the current and the frequency, generates vibration in the diaphragm attached to the coil, A sound pressure of a predetermined size that can be recognized by the ear of the user is generated.

Conventionally, in a conventional electroacoustic transducer, a frame is formed in a circular shape, and a circular yoke is inserted therein. That is, a circular magnet and a top plate are used in a yoke made of an iron metal component, (Magnetic flux) can be bridged to a cylindrical coil existing in the pores of the cylinder.

In recent years, however, it has been desired to increase the size of a liquid crystal display (LCD) as a portable terminal simultaneously performs various multimedia functions such as a camera and a video recording function. However, the conventional circular electroacoustic transducer has a wide area, Thereby causing a limitation in increasing the liquid crystal size.

Accordingly, in recent years, in order to increase the area efficiency, the frame has been formed into an elliptic shape and a circular or elliptical magnet has been placed therein. However, since the width of the short axis relative to the long axis is reduced, There was a limit in reducing the shortening width.

Further, in the conventional circular electroacoustic transducer, when the elements forming the gap are not perfectly coaxial, the gap does not have a uniform width, and the distribution of the magnetic field along the gap is distorted. In such a distorted magnetic field, the voice coil that carries the current tends to move up and down as well as shake to the left and right, which may cause distortion of the sound.

In order to solve this problem, a rectangular or rectangular electroacoustic transducer has recently been developed in which a pair of rectangular magnets are arranged in parallel within a rectangular frame, and a plate-shaped voice coil is installed in the cavity of the magnet.

For example, Korean Patent Registration No. 10-0555416 (ultra slim rectangular microphone using a flat coil member) has been introduced. In a conventional electroacoustic transducer, a yoke having a suspension mounted therein, a square magnet having a vertically oriented magnetization, and an upper plate are sequentially inserted and mounted inside a square frame, and a diaphragm is formed at the upper end of the magnet, The plate voice coil is supported through the suspension.

The magnets are arranged in parallel with each other, and the plate-shaped voice coil is inserted into the spacing space between the pair of magnets. At this time, since the voice coil is formed by winding the insulated wire many times, the current inlet and the current outlet are integrally formed (refer to FIG. 13). That is, the flow of current is always opposite between the current inlet 41 and the current outlet 42. The current inlet portion 41 and the current outlet portion 42 are installed perpendicularly to the gap 60 between the magnets (see FIG. 13).

Therefore, the electromagnetic force generated by the current flowing through the current inflow portion 41 and the current outflow portion 42 is opposite to each other, so that the force for vibrating the diaphragm is reduced. That is, since negative (-) force acting by the current inflow part (41) cancels out positive (+) force acting by the current outflow part (42) The vibration force of the vibrating diaphragm is lowered. In order to solve such a problem, conventionally, a magnetic shielding material is coated on the current inflow portion 41 to block the negative (-) force generated in association with the magnetic flux direction of the magnet. However, in order to coat the magnetic shielding material, an additional process is required, and the height of the voice coil is unnecessarily increased, which has a limitation in lowering the height of the electroacoustic transducer.

Further, in the conventional electroacoustic transducer, when the amplitude of the diaphragm 50 is not stable, break-up and distortion may occur to a great extent. Therefore, the diaphragm has a vibration width due to a damper I will crack down. However, in the case where the voice coil is circular, the width of the vibration can be stably interrupted. However, as in the recently developed rectangular electromagnetic transducer, when the voice coil is slim and flat, the diaphragm is slim The damper also has a rectangular shape so that the width of the rectangular damper is larger than that of the left and right widths, so that the width of the upper and lower vibrations can not be obtained in the end.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rectangular or rectangular electromagnetic transducer to which a plate-shaped voice coil is applied, It is possible to prevent the generation of an abnormal sound due to the distortion of the diaphragm generated during contact and to prevent a short circuit or the like caused by the contact of the voice coil with the parts in the cavity and to maintain the center of the voice coil in the cavity, And to provide an electroacoustic transducer having an electromagnetic damping function that prevents a phenomenon in which the lifetime is lowered due to the electromagnetic damping.

The present invention is also characterized in that the current inlet portion formed in the plate-shaped voice coil is bent at a right angle so that the current outlet portion is orthogonal so that negative (-) force acting by the current inlet portion is not transmitted to the current outlet portion, And an electromagnetic acoustic transducer for performing a damping function for suppressing vibration of the diaphragm by using an electromagnetic force formed by a current flowing through the current inflow portion by providing a leakage magnetic flux leaking from the magnet by horizontally installing the magnet on the upper portion of the magnet .

In addition, the present invention provides a rectangular or rectangular electroacoustic transducer having a coil member with two banding coils arranged in parallel between one gap formed between two magnets and having a narrow width and a long length, .

Means for attaining the object of the present invention is an electroacoustic transducer having an electromagnetic damping function according to the present invention,

An electroacoustic transducer comprising a frame, a diaphragm fixed to the frame, a pair of magnets provided inside the frame, and a coil member fixed to the diaphragm,

The magnet is provided in parallel to form one gap therebetween, and an upper plate is provided on the upper surface and a lower plate is provided on the lower surface to constitute a magnetic circuit.

The coil member may include two voice coils vertically installed between the air gaps to vibrate the diaphragm up and down and two damping coils horizontally installed on the gap to vibrate in a direction opposite to the voice coil, As a result,

And an electromagnetic damping function for vibrating the damping coil in a direction opposite to the voice coil when the diaphragm vibrates up and down by the voice coil to suppress vibration of the diaphragm.

In the present invention, the coil member may be formed of a banding coil in which the voice coil and the damping coil are integrated, wherein the banding coil includes two short axis portions of the track type planar coil having two long axis portions and two short axis portions, It is done by bending at right angles.

The pair of magnets is made of a rod-like magnet, a horizontal magnetic flux guided by the upper plate is formed between the gaps, and an arc-shaped magnetic flux is formed on the upper portion of the gap by a magnetic flux leaking from the magnet .

The voice coil is vertically installed between the voids to link the horizontal magnetic flux, and the damping coil is horizontally installed on the upper part of the upper plate to link the arcuate magnetic flux.

According to the present invention, since the damping coil and the voice coil are arranged so as to be orthogonal to each other, the negative force acting on the damping coil is dispersed so that the diaphragm vibrates according to the vibration of the voice coil to reproduce sound, The damping coil is prevented from vibrating in an opposite direction to the voice coil so that the vibration plate is prevented from being excessively vibrated, and the restoring force is imparted to smoothly oscillate the vibration plate.

In addition, since the vibration of the diaphragm is controlled within an appropriate range by the electromagnetic damping function of the damping coil, the present invention has an effect of obtaining a high output while minimizing the thickness of the electroacoustic transducer.

In addition, since the present invention uses one linear cavity, the length of the electroacoustic transducer can be increased instead of narrowing the width of the electroacoustic transducer. Therefore, the present invention is suitable for a rectangular or rectangular electroacoustic transducer required in recent portable audio equipment.

1 is a perspective view showing a preferred embodiment of an electroacoustic transducer having an electromagnetic damping function according to the present invention,
FIG. 2 is an exploded perspective view showing the structure of the electroacoustic transducer having the electromagnetic damping function shown in FIG. 1,
Fig. 3 is a cross-sectional view along the line AA of the electroacoustic transducer having the electromagnetic damping function shown in Fig. 1,
Fig. 4 is a cross-sectional view along the BB line of the electroacoustic transducer having the electromagnetic damping function shown in Fig. 1,
5 is an explanatory view showing an operation of an electroacoustic transducer having an electromagnetic damping function according to the present invention,
6 is a perspective view of a track type flat coil constituting a coil member according to the present invention,
7 is a perspective view showing a coil member according to the present invention,
8 is a cross-sectional view of a coil member according to the present invention,
9 is a graph showing the magnitude and direction of the forces acting on the voice coil, the damping coil and the diaphragm when a current is applied to the coil member according to the present invention,
10 is a perspective view showing the operation of the lower plate according to the present invention,
11 is a perspective view showing an example of fixing a coil member to a suspension according to the present invention,
12 is a perspective view showing another embodiment of an electroacoustic transducer having an electromagnetic damping function according to the present invention,
13 is an explanatory diagram showing an electroacoustic transducer according to the prior art.

Hereinafter, preferred embodiments of the electroacoustic transducer having the electromagnetic damping function according to the present invention will be described in detail with reference to the accompanying drawings.

1 to 4, an electroacoustic transducer 1 (hereinafter, referred to as an "acoustic transducer") having an electromagnetic damping function according to the present invention includes a predetermined frame 10, An upper plate 40a and a lower plate 40a provided on the upper surfaces of the magnets 30a and 30b and a pair of magnets 30a and 30b provided on the lower surfaces of the magnets 30a and 30b, A lower plate 50 and a coil member 80 located in a gap 33 formed between the magnets 30a and 30b and a suspension 60 to which the coil member 80 is fixed, And a diaphragm 20 to which the suspension 60 is fixed.

The coil member 80 according to the present invention is formed by arranging two banding coils 70a and 70b parallel to each other, in which the track-type planar coil 170 is bent in a '?' Shape. The banding coils 70a and 70b include two voice coils 73a and 73b vertically installed between the two magnets 30a and 30b and a gap 33 formed between the two magnets 30a and 30b and the upper plate 40a, And two damping coils 74 (74a and 74b) horizontally installed on the upper portion of the vibration plate 40b and fixed to the lower surface of the suspension 60 or the diaphragm 20.

Accordingly, when an external electrical signal is input to the coil member 80, the two voice coils 73a and 73b vibrate up and down to vibrate the diaphragm 20. At the same time, the two damping coils 74 (74a, 74b) vibrate in a direction opposite to the voice coil 73 to prevent the diaphragm 20 from vibrating excessively and to provide a restoring force.

More specifically, as shown in Figs. 4 and 5, the pair of magnets 30a and 30b are made of a rod-like permanent magnet magnetized in the vertical direction. And are formed parallel to each other to form a gap 33 therebetween. Upper plates 40a and 40b are provided on the upper surfaces of the magnets 30a and 30b and one lower plate 50 is provided on the lower surface of the magnets 30a and 30b. Therefore, the magnets 30a, 30b, the upper plates 40a, 40b, and the lower plate 50 constitute a magnetic circuit in which magnetic fields generated from the magnets 30a, 30b circulate.

The coil member 80 includes two banding coils 70a and 970b including a voice coil 73 vertically installed and a damping coil 74 orthogonal to the voice coil 73. As shown in FIG. 6, the banding coils 70a and 70b are formed by bending a track-type planar coil 170 wound in a track shape by winding a wire a plurality of times in a '' shape. The track-type planar coil 170 includes two long axes 173 and 174 and two short axes 175 and 176. The banding coils 70a and 70b are formed by bending the short axes 75 and 76 at right angles. For example, when one of the two long axes 173 and 174 is bent at a right angle about the center CC line of the short axes 175 and 176, And the other long shaft portion 174 is disposed horizontally with respect to the ground (see Fig. 7). The long axis portion 173 disposed vertically to the ground is referred to as a voice coil 73a and 73b and the long axis portion 174 horizontally disposed on the ground is called a damping coil 74a, 74b).

Therefore, when the two banding coils 70a and 70b are installed in parallel, the coil member 80 has a T-shaped cross section. That is, the coil member 80 is vertically installed so that the two voice coils 73a and 73b are opposed to each other, and the two damping coils 74a and 74b are installed horizontally so as to be positioned on the same plane, And is symmetrically installed on both sides of the coil 73.

Referring again to FIG. 5, the magnetic field generated in the one-side magnet 30a moves to the other upper plate 40b and the magnet 30b through the upper plate 40a and the gap 33. FIG. And constitutes a closed circuit circulating to the one-side magnet 30a again through the lower plate 50. Fig. At this time, a 'horizontal magnetic flux (A)' in which a magnetic flux guided by the upper plates 40a and 40b flows horizontally is formed in the gap 33, and the upper part of the gap 33, And an arc-shaped magnetic flux (B) in which a leakage magnetic flux flows in an arcuate shape is formed on the upper portions of the first and second permanent magnets 40a and 40b. The voice coil 73 of the coil member 80 is installed to link the horizontal magnetic flux A formed on the gap 33 and the damping coil 74 is formed on the gap 33 Shaped magnetic flux (B).

When an external electric signal is applied to the coil member 80, an electromagnetic force is generated in the voice coil 73 and the damping coil 74 of the coil member 80. The voice coil 73 and the damping coil 74, The directions of the currents flowing through the voice coil 73 and the damping coil 74 are always opposite to each other. Therefore, the direction of the electromagnetic force formed on the voice coil 73 and the damping coil 74 is opposite to each other.

That is, when a current flows through a conductor in a magnetic field, the conductor receives a force in a certain direction according to Fleming's left hand rule. For example, the voice coil 73a (73b) provided in the gap 33 is formed by the interaction of the magnetic force by the horizontal magnetic flux A and the electromagnetic force formed by the current flowing through the voice coil 73a (73b) The voice coil 73 vibrates in the vertical direction. The damping coils 74a and 74b horizontally installed on the gap 33 are formed by a magnetic force formed by the arcuate magnetic flux B and a current flowing through the damping coils 74a and 74b The electromagnetic force interacts to oscillate in the vertical direction.

Since the directions of currents flowing through the voice coil 73a and the damping coils 74a and 74b are always opposite to each other, the voice coil 73a and the damping coils 74a and 74b, which act on the voice coil 73a and the damping coils 74a and 74b, The directions of force are opposite to each other. That is, when the voice coils 73a and 73b move upward, the damping coils 74a and 74b move downward. When the voice coils 73a and 73b move downward, the damping coils 74a and 74b move down ) 74b are moved upward.

9 is a graphical representation of the motion direction and size of the voice coil 73, the damping coil 74, and the diaphragm 20 according to the present invention. As shown, the force acting on the voice coil 73 and the force acting on the damping coil 74 are always opposite to each other. The force acting on the damping coil 74 is much smaller than the force acting on the voice coil 73. Therefore, the vibration plate 20 vibrates up and down in accordance with the vibration of the voice coil 73 so that vibration of the vibration plate 20 is absorbed by the damping coil 74 vibrating in a direction opposite to the voice coil 73, And the restoring force that the diaphragm 20 moves in the opposite direction is given.

In this way, suppressing excessive vibration of the diaphragm 20 and causing it to vibrate smoothly is called " damping ". The damping function has been performed by the suspension 60 attached to the lower portion of the diaphragm 20 in the related art. Such a suspension 60 may be referred to as a 'mechanical damping function' because it suppresses the vibration of the diaphragm 20 by the elastic force of the leaf spring and provides an elastic restoring force to smooth the vibration of the diaphragm 20. [ On the other hand, the present invention performs a damping function by using the electromagnetic force generated in the damping coil 74 of the coil member 80, which is referred to as an 'electromagnetic damping function'.

The electromagnetic damping function according to the present invention is advantageous in that a leaf spring as a mechanical element is not used. That is, the use of the leaf spring causes an additional problem that the thickness of the acoustic transducer becomes thick and the weight becomes heavy. In addition, the electromagnetic damping function of the present invention solves the problem caused by a difference in the direction of the force between the current input portion and the current output portion, which has been a problem in the prior art, and the vibration of the diaphragm using the leakage magnetic flux leaked from the magnet It is advantageous to perform the damping function for suppressing the vibration.

As described above, the electroacoustic transducer 1 according to the present invention is configured such that the diaphragm 74 of the coil member 80 performs the electromagnetic damping function, so that the diaphragm 20 is supported by the upper cover 25 and the upper plate 40 Or the voice coil 73 hits the magnet to prevent a collision sound or a vibration and to smoothly vibrate the diaphragm 20, thereby improving sound quality. In addition, since the electromagnetic damping function is added, the vibration plate 20 can be prevented from being excessively vibrated at a high output, thereby achieving high output while minimizing the thickness of the acoustic transducer 1.

The configuration of the electroacoustic transducer 1 according to the present invention will be described in further detail with reference to Figs. 1 to 4. Fig.

First, as shown in FIG. 1, the electroacoustic transducer 1 according to the present invention has a rectangular shape with a longer length than the width. The frame 10 is made of a plastic frame and has a square frame shape. As shown in FIG. 2, the frame 10 has an inner space in which a pair of magnets 30a and 30b and upper plates 40a and 40b and a lower plate 50 are installed.

A plurality of support protrusions 12 for supporting the lower plate 50 are formed on the inner surface of the frame 10. At the upper end of the frame 10, a step portion 14 for supporting the diaphragm 20 and the edge of the suspension 60 is formed. The frame 10 is provided with a connection terminal 13 to which the connection portion 65 of the suspension 60 contacts. At the bottom of the frame 10, a plurality of sound output openings 18 for emitting a rear sound generated in the diaphragm 20 are formed. Further, engaging protrusions 15 may be formed on both sides of the inner side of the frame 10 to engage with the gap protrusions 54 of a lower plate 50, which will be described later.

The pair of magnets 30a and 30b are made of a rod. The two magnets 30a and 30b are arranged parallel to each other at regular intervals to form one gap 33 therebetween. That is, two rod magnets are used to form one linear gap 33 therebetween. If the gap 33 is formed in a straight line, it may extend in the longitudinal direction if necessary.

The magnets 30a and 30b are installed on a lower plate 50 mounted on the frame 10. The lower plate 50 is integrally formed with a fixing protrusion 53 for fixing the edges of the magnets 30a and 30b. A plurality of fixing protrusions 53 are provided on both sides of the lower plate 50 to fix the magnet 30. In addition, a gap protrusion 55 for fixing the two magnets 30a and 30b at predetermined intervals is integrally formed at the center of both sides of the lower plate 50. The gap protrusion 55 is positioned between the two magnets 30a and 30b to prevent the two magnets 30a and 30b from being engaged with each other. A coupling groove 57 into which the coupling protrusion 15 of the frame 10 is inserted is formed in the center of the gap protrusion 55 (see FIG. 10).

As shown in FIG. 11, the diaphragm 20 is formed of a thin sheet. The diaphragm 20 may include a center diaphragm 21 formed at the center and a side diaphragm 22 at the edge of the center diaphragm 21. The side diaphragm 22 is made of a material that is more flexible than the center diaphragm 21, so that the vibration of the center diaphragm 21 is smooth. The outer circumferential surface of the side diaphragm 22 is fixed to the upper end of the frame 10, and the inner circumferential surface thereof is fixed to the center diaphragm 21.

The suspension 60 is made of a thin spring plate. The suspension 60 includes an outer circumferential portion 61 and an inner circumferential portion 62 and a plurality of connecting portions 63 connecting the outer circumferential portion 61 and the inner circumferential portion 62. A penetrating portion 64 is formed between the connecting portions 63. Preferably, the outer peripheral portion 61 is formed in a ring shape and fixed to the step portion 14 of the frame 10. The connection portion 63 is narrow and bent so as to have a predetermined elastic force.

The inner peripheral portion 62 of the suspension 60 is formed in a ring shape or a plate shape. The object to which the coil member 80 is attached may be changed depending on the shape of the inner peripheral portion 62. For example, in the case of a suspension 60 having a ring-shaped inner peripheral portion 62, a center diaphragm 61 is fixed to the upper surface of the inner peripheral portion 62, and the coil member 80 is fixed to the center diaphragm 61 ) Is fixed to the lower surface. On the other hand, in the case of having the plate-shaped inner peripheral portion 62, the coil member 80 is fixed to the lower surface of the inner peripheral portion 62.

A conductive pattern for applying an electric signal to the coil member 80 is formed in the suspension 60. The suspension 60 is provided with a connection pad 66 for connecting an end of the coil member 80. [ The connection portion 65 of the suspension 60 is connected to the connection terminal 13 provided on the frame 10 to receive an external electrical signal.

The coil member 80 includes two banding coils 70a and 70b as shown in FIGS. The banding coils 70a and 70b are formed by bending the track-shaped planar coil 170 at right angles. The track-type planar coil 170 is spirally wound around the outer periphery of a bar having a rectangular cross section whose width increases from the tip end to the end, and when the winding is completed, only the rod is removed from the coil, . When the wire is wound, the lacquer coated on the wire is heated and adhered to adhere the wires to each other. Then, the coil is wound and removed from the mandrel, and the center of the short shaft portion 175 (176) is bent so that the two long shaft portions 173 and 174 are orthogonal to each other before the lacquer hardens.

The banding coils 70a and 70b may be formed by a thin flexible sheet such as a flexible printed circuit board or a flexprint. Such a thin and flexible sheet carries a predetermined electrically conductive path to itself to form an electrical path such as a coil.

Further, a plate-shaped bobbin 90 may be further provided between the two voice coils 74a and 74b. The bobbin 90 is made of an insulator and the voice coil 74a and 74b are fixed on both sides and the upper end is fixed to the lower surface of the diaphragm 20 or the suspension 60. When the voice coil 74a or 74b is sufficiently covered with an insulator, the bobbin 90 may be omitted.

Meanwhile. The suspension 60 is installed at a lower portion of the diaphragm 20, but it is also possible that the suspension 30 is positioned above the diaphragm 20. Therefore, the present invention is not particularly limited as far as the mounting position of the suspension 60 and the mounting position of the coil member 80 are concerned.

The acoustic transducer 1 according to the present invention is generally adapted to receive an external electrical signal through a suspension 60 but may be applied directly to the coil member 80 without passing through the suspension 60. [ Therefore, the present invention is not particularly limited to a method of applying an external electrical signal.

An upper lid 25 is installed on the upper part of the diaphragm 20. The upper lid 25 is provided with a sound outlet 27 for discharging sound generated according to the vibration of the diaphragm 10. [

Hereinafter, the operation of the acoustic transducer 1 having the electromagnetic damping function according to the present invention will be described.

Referring again to FIG. 5, a pair of magnets 30a and 30b are disposed parallel to each other at a predetermined interval, and upper plates 40a and 40b are formed on the upper surfaces of the magnets 30a and 30b, A lower plate 50 is provided. A horizontal magnetic flux A is formed in the gap 33 between the pair of magnets and an arc-shaped magnetic flux B is formed in the upper portion of the gap 33.

The voice coil 73 of the coil member 80 is installed perpendicularly to the gap 33 so as to cross the horizontal magnetic flux A and the damping coil 74 of the coil member 80 And is horizontally installed on the upper portion of the gap 33 so as to cross the arc-shaped magnetic flux B.

Therefore, when an external electric signal having a predetermined frequency is applied to the coil member 80, the voice coil 73 is rotated by the magnetic force generated by the horizontal magnetic flux A and the electromagnetic force generated by the current flowing through the voice coil 73, And vibrates the diaphragm 20 up and down. At the same time, the damping coil 74 is connected to the diaphragm 20, which is caused to vibrate by the voice coil 74 by a magnetic force generated by the arc-shaped magnetic flux B and an electromagnetic force generated by the current passing through the damping coil 74, ) In the opposite direction.

Since the damping coil 74 is horizontally installed on the diaphragm 20 and traverses the arc-shaped magnetic flux B, the damping coil 74 acts on the damping coil 74 according to the vertical position of the damping coil 74 The direction and magnitude of the force to be changed. For example, the angle of the coil across the arc-shaped magnetic flux B varies depending on the vertical position of the damping coil 74.

When the angle of intersection between the damping coil 74 and the arc-shaped magnetic flux B is changed, the direction and magnitude of the force acting on the damping coil 74 are changed according to the Fleming left-hand rule. Particularly, when the damping coil 74 receives a force (for example, attraction force) at a position spaced apart from the upper plates 40a and 40b by a predetermined height, when the damping coil 74 is close to the upper plates 40a and 40b It is bigger than manpower. In other words, as the diaphragm 20 is closer to the upper plates 40a and 40b, the repulsive force is strengthened instead of weakening the attraction, and as the diaphragm 20 is further away from the upper plates 40a and 40b, So that the restoring force is given to the diaphragm 20 to vibrate smoothly.

As described above, the acoustic transducer 1 according to the present invention vibrates the diaphragm 80 by the electromagnetic force due to the current flowing in the voice coil 73 of the coil member 80, thereby reproducing the sound. At the same time, the vibration plate 20 is prevented from being excessively vibrated by the electromagnetic force due to the current flowing through the damping coil 74 of the coil member 80, and a restoring force is imparted to smoothly vibrate the vibration plate 20.

According to the present invention, since the vibration of the diaphragm 20 is controlled within an appropriate range by the electromagnetic damping function, a high output can be obtained while minimizing the thickness of the electroacoustic transducer 1. Further, since the present invention uses one linear cavity, the length of the electroacoustic transducer 1 can be made longer instead of the width of the electroacoustic transducer 1, and thus it is possible to provide a rectangular electroacoustic transducer required in recent portable audio equipment.

12 is a perspective view showing another embodiment of an electroacoustic transducer having an electromagnetic damping function according to the present invention. As shown in the figure, the electroacoustic transducer 100 according to the present embodiment includes a rectangular frame 110, and a plurality of parallel spaced apart openings 133, A plurality of upper plates 140 including a plurality of pairs of magnets 130a and 130b and a pair of upper plates 140a and 140b disposed on the upper surfaces of the magnets, A plurality of lower plates 150 mounted on the lower surface of each pair of magnets and two voice coils 150 installed one by one to be located in the gap 133 between the magnets and arranged vertically to the gap 133, A plurality of coil members 180 formed integrally with two damping coils horizontally disposed on the upper plate, and a plurality of coil members 180 fixed to the upper end of the frame 110, And a suspension 160 for suppressing vertical vibrations of the diaphragm 120 installed between the diaphragm 120 and the upper plate 140. The vibration plate 120 includes a member 180 fixed in a line.

Preferably, the lower plate 150 includes a fixed protrusion for fixing the edges of the magnets 130a and 130b and a gap protrusion for fixing the two magnets 130a and 130b at predetermined intervals Respectively. In addition, the frame 110 is integrally formed with a fixing protrusion for fixing the lower plate 150. In addition, a supporting protrusion for supporting the lower plate 150 is formed integrally with the frame 110.

Meanwhile, the plurality of magnets 130 may be replaced with two longer magnets. In addition, the plurality of magnets 130 may be formed by stacking a plurality of plate-shaped magnets. The coil member 180 may be attached to the lower surface of the diaphragm 120 or the lower surface of the suspension 160. However, if the leakage flux is sufficient, the coil member 180 may be provided through a slit formed in the center of the diaphragm 120.

Therefore, when power is applied to a plurality of voice coil of the coil member, the diaphragm vibrates up and down to generate a high-output sound, and the damping coils installed on both sides of the voice coil are vibrated in a direction opposite to the voice coil, The diaphragm is prevented from being excessively vibrated, and at the same time, the diaphragm is held so as not to sway from side to side, so that high quality sound can be obtained. In addition, according to the present invention, it is possible to provide an acoustic transducer of various sizes by narrowing the width of the acoustic transducer 110, increasing the length of the acoustic transducer 110 according to convenience, and providing a number of magnets and coil members corresponding to the length.

It is to be understood that the scope of the present invention should not be construed as being limited to the above embodiments, and it is to be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. It is to be understood that both the technical idea and the technical spirit of the invention are included in the scope of the present invention.

1: electroacoustic conversion 10: frame
12: support protrusion 13: connection terminal
14: step portion 15: engaging projection
18, 27: sound outlet 20: diaphragm 21: center diaphragm 22: side diaphragm
25: upper cover 30, 30a, 30b: magnet
40, 40a, 40b: upper plate 50: lower plate
53: Fixing protrusion 55: Spacing protrusion 57: Coupling groove 60: Suspension
61: outer circumference 62: inner housewife
63: connection 65: connection
66: connection pad 70, 70a, 79b: banding coil
73: Voice coil 74: Damping coil
80: coil member 90: bobbin
170: track type planar coils 173, 174:
175, 176:

Claims (16)

An electroacoustic transducer comprising a frame, a diaphragm fixed to the frame, a pair of magnets provided inside the frame, and a coil member fixed to the diaphragm,
The magnet is provided in parallel to form one gap therebetween, and an upper plate is provided on the upper surface and a lower plate is provided on the lower surface to constitute a magnetic circuit.
The coil member may include two voice coils vertically installed between the air gaps to vibrate the diaphragm up and down and two damping coils horizontally installed on the gap to vibrate in a direction opposite to the voice coil, As a result,
And the damping coil performs an electromagnetic damping function to suppress the vibration of the diaphragm when the diaphragm vibrates up and down by the voice coil. The method according to claim 1,
Wherein the coil member comprises a banding coil in which the voice coil and the damping coil are integrated, wherein the banding coil is formed by bending the two short axes of the track type planar coil having two long axes and two short axes at a right angle Wherein the electroacoustic transducer has an electromagnetic damping function. 3. The method of claim 2,
Wherein a pair of magnets are made of a rod-like magnet, a horizontal magnetic flux is formed in a gap between the upper plates provided on the magnet, and an arc-shaped magnetic flux is formed on the gap by a magnetic flux leaking from the magnet And an electromagnetic damping function of the electroacoustic transducer. The method of claim 3,
Wherein the voice coil of the coil member is vertically installed to link the horizontal magnetic flux, and the damping coil is horizontally installed to link the arc-shaped magnetic flux. 5. The method of claim 4,
Wherein the diaphragm is provided with a suspension made of a leaf spring. 6. The method of claim 5,
Wherein the coil member is electrically connected to the suspension to receive an external electrical signal. ≪ RTI ID = 0.0 > 8. < / RTI > A rectangular frame;
A pair of magnets installed in the frame and installed parallel to each other at a predetermined distance;
Two upper plates respectively installed on the upper surface of the magnet;
A lower plate provided on the lower surface of the magnet;
A coil member comprising two voice coils disposed perpendicularly to the gap formed between the magnets and two damping coils disposed horizontally above the upper plate;
A diaphragm fixed to an upper end of the frame and having two damping coils of the coil member fixed in the center;
And a suspension installed between the diaphragm and the upper plate to suppress vibration of the diaphragm,
Wherein the electromagnetic damping function performs the electromagnetic damping function to vibrate the vibration plate in a direction opposite to the voice coil when the vibration plate vibrates up and down by the voice coil of the coil member. Gt; 8. The method of claim 7,
Wherein the pair of magnets are formed by vertically polarized bars or rectangles. 9. The method of claim 8,
Wherein the coil member includes two banding coils having the voice coil and the damping coil integrally formed in parallel to each other, wherein the banding coil includes two short axes and two short axes, And the second electrode is bent at a right angle. 10. The method according to any one of claims 7 to 9,
Wherein an electromagnetic damping function is provided at an edge of the lower plate, and a fixed protrusion for fixing the edge of the magnet and a gap protrusion provided between the two magnets to allow a pair of magnets to fall at a predetermined interval are integrally formed. And an electroacoustic transducer. 11. The method of claim 10,
The frame has a rectangular frame shape. On the inner side, a plurality of support protrusions for supporting the lower plate are formed. On both sides of the inner side of the frame, a coupling protrusion And an electromagnetic damping function of the electroacoustic transducer. 11. The method of claim 10,
Wherein the suspension has a plurality of connection portions formed between an outer circumferential portion fixed to the frame, an inner circumferential portion fixed to the diaphragm, and an inner circumference between the outer circumferential portion and the inner circumferential portion. 13. The method of claim 12,
Wherein the coil member is fixed to an inner surface of the suspension. ≪ Desc / Clms Page number 19 > A rectangular frame;
A plurality of pairs of magnets installed inside the frame and spaced apart from each other by a predetermined distance to form a gap therebetween;
A plurality of upper plates respectively installed on the upper surfaces of the magnets;
A plurality of lower plates provided on the lower surface of each pair of magnets;
A plurality of coil members formed integrally with two voice coils which are installed one by one in the gap between the magnets and are arranged perpendicular to the gap, and two damping coils horizontally arranged on the upper plate;
A diaphragm fixed to an upper end of the frame and having the plurality of coil members fixed in a line in the center;
And a suspension for suppressing vertical vibration of the diaphragm installed between the diaphragm and the upper plate,
And an electromagnetic damping function for suppressing vibration of the vibration plate by vibrating the damping coil in a direction opposite to the voice coil when the vibration plate vibrates up and down by the voice coil of the coil member. Electroacoustic transducer. 15. The method of claim 14,
Wherein the coil member includes two banding coils having the voice coil and the damping coil integrally formed in parallel to each other, wherein the banding coil includes two short axes and two short axes, And a plate-shaped bobbin is provided between the two voice coils. The electroacoustic transducer according to claim 1, The method of claim 15, wherein
Wherein the lower plate is integrally formed with a spacing protrusion for fixing the two magnets at predetermined intervals, and the frame is integrally formed with a fixing protrusion for fixing or supporting the lower plate. And an electroacoustic transducer.

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