KR101745492B1

KR101745492B1 - Speaker Having Flat-Type Voice Coil

Info

Publication number: KR101745492B1
Application number: KR1020150089690A
Authority: KR
Inventors: 민동훈; 김주배; 권순관
Original assignee: 민동훈
Priority date: 2015-06-24
Filing date: 2015-06-24
Publication date: 2017-06-12
Also published as: KR20170000873A

Abstract

A flat-plate speaker in which the configuration of a magnetic circuit is improved is disclosed. A flat-type speaker according to the present invention includes: a flat-type voice coil plate including an upper horizontal coil region and a lower horizontal coil region; A pair of upper-layer permanent magnets disposed on both sides of the upper lateral coil region, the pair of upper-layer permanent magnets having a magnetization direction perpendicular to the voice coil plate; And a pair of lower layer permanent magnets disposed on both sides of the lower lateral coil region and each having a magnetization direction perpendicular to the voice coil plate, wherein the pair of upper layer permanent magnets and the pair of lower layer permanent magnets Are arranged at a predetermined interval.

Description

[0001] Speaker Having Flat-Type Voice Coil [0002]

The present invention relates to a speaker, and more particularly, to a planar speaker including a planar voice coil plate and a magnetic body disposed on both sides of the voice coil plate and forming a magnetic field.

The speaker has a voice coil and a diaphragm disposed in a magnetic field, and generates a sound wave of a small-sized wave form in the air by vibrating the diaphragm using a Lorentz force generated in the voice coil by an electric signal. Conventionally, a circular speaker that vibrates a cone-shaped diaphragm by using a voice coil coiled in a cylindrical shape has been widely used. However, recently, due to the trend of downsizing and thinning of a display device or a mobile terminal equipped with an audio system, The use of flat-panel loudspeakers to reduce installation space is increasing.

The flat plate type speaker generally includes a pair of magnetic bodies arranged at predetermined intervals from each other to form a magnetic space in which a magnetic field is formed therebetween, a planar voice coil plate disposed in the magnetic space, And a diaphragm that is vertically coupled to the upper end of the voice coil plate and vibrates by the motion of the voice coil plate. The voice coil plate includes a base plate in the form of a plate or a film, and a voice coil printed on the surface of the base plate in a track form or in a similar form. The voice coil pattern is formed in a direction parallel to the diaphragm and has a lateral coil region for generating a Lorentz force in a direction perpendicular to the plane including the diaphragm. Further, a vertical coil region connecting the upper horizontal coil region close to the diaphragm and the lower horizontal coil region distant from the diaphragm is also provided among the horizontal coil regions.

In the conventional flat type speaker, the pair of magnetic bodies includes a pair of permanent magnets and a yoke plate coupled to the upper and lower portions of the respective permanent magnets. Here, one pair of permanent magnets is disposed on both sides of the voice coil plate, and the magnetization direction thereof is parallel to the voice coil plate. On the other hand, since the direction of the magnetic field required for moving the voice coil plate is perpendicular to the voice coil plate, a direction perpendicular to the voice coil plate is formed in the magnetic space by the yoke plates disposed above and below the pair of permanent magnets Magnetic field.

Korean Patent Registration Nos. 10-0576266, 10-0576267, 10-0533715

The present invention relates to a planar speaker in which the magnetic circuit has a different structure from that of the prior art, so that the density of the magnetic flux crossing the transverse coil region of the voice coil plate is higher than that of the conventional flat- In which the direction of the voice coil is perpendicular to the voice coil is wider, and the stability of the output and operation is improved.

In order to solve the above-mentioned problems, a flat speaker according to the present invention includes: a plate-shaped voice coil plate including an upper horizontal coil region and a lower horizontal coil region; A pair of upper-layer permanent magnets disposed on both sides of the upper lateral coil region, the pair of upper-layer permanent magnets having a magnetization direction perpendicular to the voice coil plate; And a pair of lower layer permanent magnets disposed on both sides of the lower lateral coil region and each having a magnetization direction perpendicular to the voice coil plate, wherein the pair of upper layer permanent magnets and the pair of lower layer permanent magnets Are arranged at a predetermined interval.

Here, the expressions of upper and lower layers, upper and lower portions are not absolute positions, but represent relative positions viewed from the voice coil plate toward the upper side and the lower side from the diaphragm side. The pair of upper permanent magnets and the pair of lower permanent magnets mean that the permanent magnets are arranged on both sides of the voice coil plate with a pair therebetween.

Wherein the pair of upper permanent magnets and the pair of lower permanent magnets are opposite in magnetization direction and both sides of the pair of upper permanent magnets and the pair of lower permanent magnets are parallel to the voice coil plate And a pair of side yoke plates connected to each other to form a magnetic circuit.

The spacer may further include a spacer disposed between the pair of upper-layer permanent magnets and the pair of lower-layer permanent magnets to keep the predetermined gap therebetween constant.

Each of the upper pair of permanent magnets and the pair of lower pair of permanent magnets may have a relatively larger width in a direction perpendicular to the magnetization direction than a thickness of the pair of lower layer permanent magnets.

The predetermined interval may be smaller than the width of the pair of upper permanent magnet and the pair of lower permanent magnet in a direction perpendicular to the magnetization direction thereof. Further, the predetermined interval may be 1 to 2 mm.

The vertical width of the upper and lower horizontal coil regions may be greater than the width of the pair of upper permanent magnets and the pair of lower permanent magnets in a direction perpendicular to the magnetization direction thereof.

In this case, when the diaphragm is in a balanced state, the upper lateral coil region is disposed between the pair of upper permanent magnets and the upper side thereof, and the lower lateral coil region is located between the pair of lower permanent magnets And may be disposed outside the lower side thereof. When the diaphragm is at the maximum displacement, the lower end of the upper lateral coil region does not exceed the center line bisecting the predetermined gap at the upper and lower sides, and when the diaphragm is at the maximum displacement upward, And the upper end may be disposed so as not to exceed the center line.

According to the present invention, by making the structure of the magnetic circuit different from that of the conventional flat-plate speaker, the density of the magnetic flux crossing the transverse coil region of the voice coil plate is higher than that of the conventional flat- , And a width of a region where the direction of the magnetic flux is perpendicular to the voice coil is wider. The present invention has the effect of providing a flat-plate-type speaker with improved output and operation stability through the above-described configuration.

1 shows a main configuration of a flat type speaker according to an embodiment of the present invention.
FIG. 2 shows the intensity and direction of the magnetic field of the magnetic space in the embodiment of FIG.
FIG. 3 is a graph showing the variation of the magnetic flux density according to the thickness of the spacer in the embodiment of FIG.
FIG. 4 shows the relative positional change of the voice coil plate with respect to the magnetic space when the vibration plate vibrates in the embodiment of FIG.
5 shows a voice coil plate of a flat type speaker according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The embodiments described below can be modified in various ways, and the scope of the present invention is not limited to the following embodiments. The embodiments of the present invention are provided to clearly convey the technical idea of the present invention to those skilled in the art.

1 shows a main configuration of a flat type speaker according to an embodiment of the present invention.

A diaphragm 20 for generating vibration of air is arranged at the upper end of the voice coil plate 10 disposed vertically in the center of the figure using up-and-down motion of the voice coil plate 10. Although not shown in the figure, the diaphragm 20 is connected to a fixing structure such as a speaker housing through a structure serving as a spring-damper, and the diaphragm 20 is displaced in a direction perpendicular to the plane within a limited range. .

The voice coil plate 10 may be formed by printing a conductive voice coil pattern on one surface or both surfaces of a base substrate, and may be formed by winding a voice coil on one surface or both surfaces of the base substrate. The voice coil plate 10 includes an upper transverse coil region 11 and a lower transverse coil region 12. The upper and lower transverse coil regions 11 and 12 are elongated in the transverse direction, that is, in the direction perpendicular to the vibration direction of the voice coil plate 10, such that a conductive coil or coil pattern (hereinafter referred to as a coil) And a plurality of coils extending in parallel with each other. The plurality of coils of the upper horizontal coil region 11 and the lower horizontal coil region 12 are connected to each other through a plurality of coils of a vertical coil region not shown, Lt; / RTI > Whereby a current corresponding to an electric signal for generating sound flows through the voice coil. More specifically, the voice coil is continuously formed in a rectangular or track shape elongated in the depth direction of the figure from a single lead wiring to a portion drawn out to the outside of the voice coil plate 10 through the opposite lead wiring .

A pair of upper permanent magnets 41 whose magnetization directions are perpendicular to the voice coil plate 10 are disposed on both sides of the upper lateral coil region 11 and on both sides of the lower lateral coil region 12, And a pair of lower permanent magnets 42 whose magnetization directions are perpendicular to the voice coil plate 10 are disposed. The pair of upper-layer permanent magnets 41 and the pair of lower-layer permanent magnets 42 are arranged at a predetermined interval from each other. To this end, a spacer 44 may be disposed between the pair of upper permanent magnets 41 and the pair of lower permanent magnets 42 to keep the predetermined gap constant. The thickness of the spacer 44 defining the predetermined gap may be smaller than a width in a direction perpendicular to the magnetization direction of the pair of upper permanent magnets 41 and the pair of lower permanent magnets 42 have. The predetermined interval, that is, the thickness of the spacer 44 may be 1 to 2 mm. This is the range of the interval at which a sufficient magnetic flux density can be obtained at the position of the voice coil plate 10 when applied to a general flat type speaker having a width of 2 mm or more of the permanent magnets constituting the upper layer and the lower layer. The appropriate range of the predetermined interval will be described later in more detail.

According to this embodiment, the pair of upper-layer permanent magnets 41 and the pair of lower-layer permanent magnets 42 are opposite in magnetization direction, and the pair of upper-layer permanent magnets 41 and the pair And a pair of side yoke plates 43 connecting both sides of the lower permanent magnet 42 of the lower permanent magnet 42 parallel to the voice coil plate 10 to form a magnetic circuit. For example, in the figure, the left permanent magnet 41L of the pair of upper permanent magnets 41 is disposed such that the S pole faces the voice coil plate 10 and the N pole faces outward. The right permanent magnet 41R of the pair of upper permanent magnets 41 may be arranged such that the N pole faces the voice coil plate 10 and the S pole faces outward. At this time, the left permanent magnet 42L of the pair of lower permanent magnets 42 is arranged so that the N pole is directed to the voice coil plate 10, the S pole of the permanent magnet 42R on the right side is arranged to face the voice coil plate 10, (10). A side yoke plate 43R on the right side that connects the upper permanent magnet 41R on the right side with the lower permanent magnet 42R on the right side and a lower side permanent magnet 41R on the left side of the upper left permanent magnet 41R, The left side yoke plate 43L connecting the permanent magnets 42L may be disposed.

Here, the expressions of the upper layer, the lower layer, the upper and lower portions and the like are not absolute positions, but represent relative positions viewed from the voice coil plate 10 toward the upper side and the lower side from the diaphragm 20 side. The pair of upper permanent magnets 41 and the pair of lower permanent magnets 42 are arranged such that permanent magnets 41L-41R and 42L-42R are arranged on both sides of the voice coil plate 10 It is arranged in a pair. In other words, the upper layer permanent magnet 41 includes a pair of permanent magnets 41L and 41R, and the lower layer permanent magnet 42 also includes a pair of permanent magnets 42L and 42R. The present invention is not limited to a permanent magnet. As the permanent magnets 41L, 41R, 42L, and 42R, for example, neodymium (NdFeB) magnets may be employed, and the side yoke plates 43L and 43R may employ pure iron or low carbon steel having high permeability .

In the voice coil plate 10, the widths of the upper lateral coil region 11 and the lower lateral coil region 12 in the up-and-down direction correspond to the widths of the pair of upper-layer permanent magnets 41, The width of the permanent magnet 42 in the vertical direction, that is, the width in the direction perpendicular to the magnetization direction thereof. In this case, as shown in FIG. 1, when the diaphragm 20 is in a balanced state, the upper transverse coil region 11 is located between the pair of upper permanent magnets 41, that is, And the lower transverse coil region 12 is disposed between the pair of lower permanent magnet magnets 42, that is, the lower magnetic flux density region 421 and the lower outside thereof .

Each of the upper pair of permanent magnets 41 and the pair of lower pair permanent magnets 42 may have a relatively larger width in a direction perpendicular to the magnetization direction than a thickness in a direction parallel to the magnetization direction . This means that the permanent magnets 41L, 41R, 42L, and 42R shown in this drawing, for example, have larger lengths than the transverse sides of the rectangular cross section. The lower coercive force density region 421 between the pair of upper permanent magnets 41 and the lower coercive force density region 411 between the pair of lower permanent magnets 42 is perpendicular to the voice coil plate 10 And a larger number of transverse coils in the upper transverse coil region 11 and the lower transverse coil region 12 of the voice coil plate 10 are connected to the voice coil plate 10 Thereby effectively generating an electromagnetic force in a parallel direction.

FIG. 2 shows the intensity and direction of the magnetic field of the magnetic space in the embodiment of FIG.

As shown in the figure, horizontal parallel magnetic lines of force across these areas are widely distributed in the upper magnetic flux density region 411 and the lower magnetic flux density region 421. The output from the flat speaker is caused by the electromagnetic force that moves the diaphragm 20 up and down in accordance with the current flowing along the voice coil plate 10, And the intensity of the magnetic field in the direction perpendicular to the voice coil plate 10 is proportional to the intensity of the current flowing along the coil of the voice coil plate 10. According to the present embodiment, the widths of the upper and lower magnetic flux density regions 411 and 421, in which a magnetic field in a direction perpendicular to the voice coil plate 10 is formed, are wider than those of the conventional flat type speaker having permanent magnets of the same volume And it is efficient.

Magnetic flux density
(Gauss) Thickness of permanent magnet (mm) Width of permanent magnet (mm) 2.0 2.5 3.0 3.5 2.0 6997.5 7104.0 7158.6 7188.4 2.5 7648.8 7797.4 7879.7 7928.0 3.0 8025.3 8209.5 8322.2 8394.4 3.5 8165.5 8397.5 8551.6 8659.0

In Table 1, the widths of the pair of upper permanent magnets 41 and the pair of lower permanent magnets 42 (the direction perpendicular to the magnetization direction, that is, the length of the longitudinal side in the drawing) And the maximum magnetic flux density in the upper and lower magnetic flux density regions 411 and 421 when the thickness (corresponding to the direction parallel to the magnetization direction, that is, the length of the roadside in the drawing) is different.

As the overall size (width * thickness) of the magnets increases, the maximum magnetic flux density increases, among which the width of the permanent magnets exerts a greater influence on the maximum magnetic flux density. More specifically, in the table above, it can be seen that a higher maximum magnetic flux density is obtained when a permanent magnet having a width of 3.5 mm and a thickness of 3.0 mm is employed, as compared with the case of adopting a permanent magnet having a width of 3.0 mm and a thickness of 3.5 mm have. As described above, in the flat type speaker according to the present invention, the width of the permanent magnet is made larger than its thickness, so that a higher output can be obtained compared with the size.

On the other hand, in the area between the spacers 44, the upper author density area 412 and the lower author density area 422 are formed with reference to the center line (actually, the center face) in the drawing. Curve-like magnetic lines of force are distributed in the upper and lower author density regions 412 and 422. In this section, the magnetic flux density is rapidly reduced and the direction of the magnetic field is reversed at the centers thereof, so that the effect on the voice coil plate 10 is negligible .

FIG. 3 is a graph showing the variation of the magnetic flux density according to the thickness of the spacer in the embodiment of FIG. The maximum magnetic flux density varies depending on the thickness of the spacer 44, that is, the distance between the pair of upper-layer permanent magnets 41 and the pair of lower-layer permanent magnets 42 even when the sizes of the permanent magnets are the same. 1, when the width of the permanent magnets 41L, 41R, 42L, and 42R is 3 mm and the thickness is 2 mm, the thickness of the spacers 44 is increased from 0.5 mm to 3 mm in 0.5 mm increments And the magnetic flux density according to the distance from the center line (5.5 mm on the horizontal axis of the graph).

Spacer
Thickness (mm) Maximum magnetic flux density
(Gauss) 0.5 7810 1.0 7914 1.5 7974 2.0 8003 2.5 8015 3.0 8018

Table 2 above shows the maximum magnetic flux density according to the thickness of the spacer 44, that is, the height of the peak of each curve in the graph of FIG. 3 and Table 2, the maximum magnetic flux density is rapidly increased until the thickness of the spacer 44, that is, the distance between the upper permanent magnet 41 and the lower permanent magnet 42 is about 2.0 mm However, it is seen that the growth rate is rapidly declining as it exceeds 2.0mm. As the thickness of the spacer 44 increases, the maximum magnetic flux density increases somewhat. However, the height of the entire plate-type speaker is increased, and the height of the both side yoke plates 43 in FIGS. 1 and 2 increases accordingly. Raw material costs will rise. Therefore, the thickness of the spacer 44 can be adopted between about 1 mm and about 2 mm.

FIG. 4 shows the relative positional change of the voice coil plate with respect to the magnetic space when the vibration plate vibrates in the embodiment of FIG.

4 (a) shows a state in which the diaphragm 20 and the voice coil plate 10 are displaced downward to the maximum, and FIG. 4 (b) shows a state in which the diaphragm 20 and the voice coil plate 10 are moved upward It shows the state of maximum displacement. the lower end of the upper transverse coil region 11 does not extend beyond the center line bisecting the predetermined gap in the upper and lower directions when the diaphragm 20 is at the maximum displacement downward as shown in FIG. The upper end of the lower transverse coil region 12 may be disposed so as not to exceed the center line when the movable transducer 20 is at the maximum displacement.

The number of coils located in the upper magnetic flux density region 411 of the upper lateral coil region 11 and the number of coils located in the lower magnetic flux density region 421 of the lower lateral coil region 12 are large, The electromagnetic force is uniformly applied to the voice coil plate 10 within the amplitude range of the diaphragm 20 to provide excellent acoustic characteristics. According to the embodiment of the present invention, when the voice coil plate 10 moves downward as shown in (a), the coils located on the lower end side of the upper transverse coil region 11 are separated from the upper intrinsic density region 411 by the upper intrinsic density The lower coaxial region 411 does not move down to the region 412 but the coils located outside the upper coaxiality region 411 enter the inside and reinforce the electromagnetic force. When the voice coil plate 10 moves upward as shown in (b) The coils located on the upper end side of the lower magnetic flux density region 421 rise from the lower magnetic flux density region 421 to the lower magnetic flux density region 422 but the coils located outside the lower magnetic flux density region 421 enter the inside, It does. Even when the voice coil plate 10 is at the maximum displacement, the lower end coil of the upper transverse coil region 11 and the upper end coil of the lower transverse coil region 12 do not exceed the center line where the direction of the magnetic field is changed, It is possible to prevent the occurrence of electromagnetic force of

5 shows a voice coil plate of a flat type speaker according to another embodiment of the present invention.

The voice coil plate 10M includes an upper transverse coil region 11P and a lower transverse coil region 11B formed on one or both sides of the base substrate 101 with a multilayer coil pattern sandwiching the insulating layer 102 therebetween, And a coil region 12P. The multilayer coil pattern may be formed by various methods for forming a conductive pattern, such as an etching process, and they may include an interlayer connection structure via a via hole.

10, 10M: Voice coil plate
11, 11P: Upper horizontal coil area (voice coil)
12, 12P: Lower horizontal coil area (voice coil)
20: diaphragm
41: upper permanent magnet
42: Lower layer permanent magnet
43: Side yoke plate
44: Spacer

Claims

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A plate-shaped voice coil plate including an upper transverse coil region and a lower transverse coil region, and a diaphragm connected to the upper transverse coil region and the lower transverse coil region;
A pair of upper-layer permanent magnets disposed on both sides of the upper lateral coil region, the pair of upper-layer permanent magnets having a magnetization direction perpendicular to the voice coil plate; And
And a pair of lower layer permanent magnets disposed on both sides of the lower lateral coil region and having a magnetization direction perpendicular to the voice coil plate,
Wherein the pair of upper-layer permanent magnets and the pair of lower-layer permanent magnets are disposed at a predetermined interval from each other,
Wherein the widths of the upper and lower horizontal coil regions in the vertical direction are larger than the widths of the pair of upper permanent magnets and the pair of lower permanent magnets in a direction perpendicular to the magnetization direction thereof,
Flat-panel speakers.

8. The method of claim 7,
When the vibration plate is in an equilibrium state,
Wherein the upper lateral coil region is disposed between the upper pair of permanent magnets and outside the upper pair of permanent magnets,
Wherein the lower lateral coil region is disposed between the pair of lower layer permanent magnets and on the lower outside thereof,
Flat-panel speakers.

8. The method of claim 7,
Wherein a lower end of the upper lateral coil region does not exceed a center line bisecting the predetermined gap vertically when the diaphragm is at the maximum displacement downward,
Wherein when the diaphragm is displaced upward to the maximum, the upper end of the lower horizontal coil region does not exceed the center line,
Flat-panel speakers.