KR20150051359A

KR20150051359A - Speaker Having Flat-Type Voice Coil

Info

Publication number: KR20150051359A
Application number: KR1020130132675A
Authority: KR
Inventors: 유승열
Original assignee: 주식회사 드림소닉
Priority date: 2013-11-04
Filing date: 2013-11-04
Publication date: 2015-05-13

Abstract

A planar speaker in which output is improved and vibration mode is stable is disclosed. According to an aspect of the present invention, there is provided a planar speaker comprising: a top loudspeaker region having a high magnetic flux density and a first direction of a magnetic field from an upper portion of the magnetic space, An upper autogenous region having a low magnetic flux density and a magnetic field direction being the first direction, a lower author region having a lower magnetic flux density and a second direction in which the direction of the magnetic field is opposite to the first direction, A pair of magnetic bodies forming a lower stator magnetic field region in the second direction; A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space to generate a displacement within a limited range by an electromagnetic force acting on the voice coil plate, And a plurality of lower horizontal coils having a component parallel to the diaphragm and flowing in a second direction in which the current is opposite to the first direction, And an upper end of the lower transverse coil region is arranged to reach the upper author region when a maximum displacement of the diaphragm occurs.

Description

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

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker, and more particularly, to a flat speaker having a flat voice coil plate.

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 printed in the form of a track or the like 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.

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

An object of the present invention is to provide a planar speaker capable of improving output by arranging a coil or a coil pattern by efficiently utilizing an area of a voice coil plate in a magnetic space.

Further, according to the present invention, a vertical coil region for generating a force in a direction independent of vibration of a diaphragm is disposed out of a magnetic space among a horizontal coil region and a vertical coil region of a voice coil plate, The purpose is to provide a speaker.

In order to solve the above-mentioned problems, a flat speaker according to one aspect of the present invention is arranged to be spaced apart from each other by a predetermined distance to form a magnetic space, wherein the magnetic flux density is high from the top of the magnetic space, A lower autogenous region having a lower magnetic flux density and a lower magnetic flux density and a second direction in which a direction of a magnetic field is opposite to the first direction; A pair of magnetic bodies forming a lower annular magnetic region having a high magnetic flux density and a direction of a magnetic field in the second direction; A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space to generate a displacement within a limited range by an electromagnetic force acting on the voice coil plate, And a plurality of lower horizontal coils having a component parallel to the diaphragm and flowing in a second direction in which the current is opposite to the first direction, And an upper end of the lower transverse coil region is arranged to reach the upper author region when a maximum displacement of the diaphragm occurs.

The voice coil may be formed such that a lower end of the upper lateral coil region is located in the upper author region when there is no displacement of the diaphragm.

The magnetic flux density may be nonlinearly changed according to the positions of the boundary between the upper and lower autonomous regions and the upper autogenous region and between the lower autogenous region and the sub-autonomous region.

Wherein each of the pair of magnetic bodies comprises: a permanent magnet in which an anode is disposed on the top and bottom; And an upper yoke plate and a lower yoke plate respectively disposed on the upper surface and the lower surface of the permanent magnet, wherein the upper magnetostrictive region is sandwiched between a pair of upper yoke plates facing each other, Between a pair of opposing lower yoke plates, and the upper and lower author regions may be formed between a pair of opposing permanent magnets.

Wherein the voice coil is disposed on both sides of the upper and lower transverse coil regions and comprises a vertical coil region constituted by vertical coils including components vertical to the diaphragm by connecting coils constituting the upper and lower transverse coil regions, And at least a part of the vertical coil region may be disposed outside the magnetic space.

According to an aspect of the present invention, there is provided a planar speaker comprising: a pair of magnetic bodies arranged at predetermined intervals to form a magnetic space; A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space to generate a displacement within a limited range by an electromagnetic force acting on the voice coil plate, And a plurality of lower horizontal coils having a component parallel to the diaphragm and flowing in a second direction in which the current is opposite to the first direction, And the plurality of upper transverse coils and the plurality of lower transverse coils may be evenly distributed from the upper end of the upper transverse coil region to the lower end of the lower transverse coil region.

According to an aspect of the present invention, there is provided a planar speaker comprising: a pair of magnetic bodies arranged at predetermined intervals to form a magnetic space; A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space and generating a displacement within a limited range by an electromagnetic force acting on the voice coil plate, wherein the voice coil has a component perpendicular to the diaphragm And at least a part of the vertical coil region is disposed outside the magnetic space.

All of the vertical coil regions may be disposed outside the magnetic space.

According to the present invention, it is possible to provide a planar speaker capable of improving output by arranging a coil or a coil pattern by efficiently utilizing the area of the voice coil plate in the magnetic space.

Further, according to the present invention, by disposing the vertical coil region out of the magnetic space in the transverse coil region and the vertical coil region of the voice coil plate, generation of force in a direction independent of vibration of the diaphragm is originally blocked, And the manufacturing cost can be reduced by reducing the size of the magnetic body without loss of the output.

1 is an exploded perspective view showing a main part of a flat type speaker according to an embodiment of the present invention.
2 is a front view showing a voice coil plate of the flat speaker according to the embodiment of FIG.
3 is a schematic view showing the arrangement of the voice coil and the magnetic body in operation of the flat speaker according to the embodiment of FIG.
FIG. 4 is a schematic view showing a Lorentz force acting in a maximum displacement state of the voice coil plate in the flat speaker according to the embodiment of FIG. 1; FIG.
5 is a front view showing the arrangement of the voice coil and the magnetic body in the flat speaker according to the embodiment of FIG.

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 is an exploded perspective view showing a main part of a flat type speaker according to an embodiment of the present invention. According to this embodiment, the upper end of the planar voice coil plate 100 having the voice coil 11 on the surface side of the base substrate 10 is vertically coupled to the diaphragm 20 that vibrates the air. The periphery of the diaphragm 20 is connected to a fixing structure such as a housing of a speaker through a spring-damper structure (not shown), and is installed so as to be able to vibrate in a limited range while displacing in a direction perpendicular to the plane.

The voice coil 11 may be formed by winding a coil on one surface or both surfaces of the base substrate 10, or may be formed by printing a conductive pattern on one surface or both surfaces of the base substrate 10 It is possible. The voice coil 11 generates a Lorentz force so that the diaphragm 20 can vibrate in a magnetic space in which a magnetic field is formed by the pair of magnetic bodies 40. To this end, the voice coil 11 includes a section extending laterally to have a component parallel to the diaphragm 20. For convenience of explanation, a direction parallel to the diaphragm 20 in the base substrate 10 will be referred to as a transverse direction, and a direction perpendicular thereto will be referred to as a longitudinal direction.

Although not shown in the drawing, both ends of the voice coil 11 are connected to terminals of a speaker through lead wirings. So that a current accompanied by an electric signal for generating sound flows through the voice coil 11. More specifically, the voice coil 11 is formed to be continuous with a rectangular or oval shape extending in the transverse direction from the one lead wire to the portion drawn out to the outside of the voice coil plate 100 through the opposite lead wire . The form in which the voice coil 11 is wound or printed will be described in more detail below with reference to the related drawings.

The pair of magnetic bodies 40 are arranged at predetermined intervals with the voice coil plate 100 interposed therebetween. The pair of magnetic bodies 40 may be installed to be spaced apart by a housing of a speaker or a structure fixed thereto. The pair of magnetic bodies 40 forms a magnetic field in a direction perpendicular to the plane of the voice coil plate 100. Each of the magnetic bodies 40 includes an upper yoke plate 42a and a lower yoke plate 42b disposed on upper and lower surfaces of the permanent magnet 41, . &Lt; / RTI > As the permanent magnet 41, for example, a neodymium (NdFeB) magnet may be employed, and the upper and lower yoke plates 42a and 42b may be made of pure iron or low carbon steel having high magnetic permeability. In the pair of magnetic bodies 40, the pair of permanent magnets 41 are arranged such that the opposite polarities of the pair of permanent magnets 41 correspond to each other.

2 is a front view showing a voice coil plate of the flat speaker according to the embodiment of FIG. When the voice coil 11 formed on the voice coil plate 100 is divided into regions, a current flows in a first direction, for example, from left to right on the drawing, with a component parallel to the diaphragm 20, An upper transverse coil region 110A constituted by a coil 11a and a plurality of second transverse coil regions 11A which have a component parallel to the diaphragm 20 and whose current flows in a second direction opposite to the first direction, A lower horizontal coil region 110B constituted by a lower horizontal coil 11b and vertical coils constituted by vertical coils including components vertical to the diaphragm 20 on both sides of the upper and lower horizontal coil regions 110A and 110B. And a coil region 110C.

The plurality of upper transverse coils 11a and the plurality of lower transverse coils 11b may be disposed on the base substrate 10 in the direction of the displacement of the voice coil plate 100, In a portion corresponding to the magnetic space between them. For example, it may be formed at a constant pitch Pa across the upper and lower transverse coil regions 110A and 110B. A coil at the lowermost end of the plurality of upper lateral coils 11a and a plurality of lower lateral coils 11b at the boundary (coil center line CC) of the upper horizontal coil region 110A and the lower horizontal coil region 110B May be different from the coil pitch Pa of other portions but may be formed so as not to exceed twice the coil pitch Pa. By doing so, the Lorentz force acting on the diaphragm 20 can be increased by efficiently utilizing a larger number of lateral coils in the unit area of the voice coil plate 100. An increase in the Lorentz force leads to an increase in the output of the speaker.

In this embodiment, as the material of the base substrate 10 constituting the voice coil plate 100, a polyimide such as a high heat resistant polymer film such as Kapton (R) film of DuPont (TM) Film can be employed. Since the voice coil plate 100 often reaches a high temperature of 100 DEG C or more due to joule heat generated in the voice coil 11 at the time of operation of the loudspeaker, It is preferable to adopt a material having less strain. This is because when the base substrate 10 is thermally deformed in a narrow magnetic space, it may cause a defect in friction between the voice coil plate 100 and the magnetic body.

The base substrate 10 may have a chamfered corner 13. Heat generated during operation of the speaker is first accumulated in the voice coil plate 100 to raise the temperature. At this time, the degree of thermal expansion of each portion of the voice coil plate 100 may vary and cause thermal deformation. The largest displacement occurs when the thermal deformation occurs, and the portion directly contacting with the surrounding magnetic body is a corner portion farther from the diaphragm in the base substrate 10. Therefore, in the flat speaker according to the present embodiment, the corner portion 13 of the base substrate 10 is chamfered. With this structure, even if a slight thermal deformation occurs in the base substrate 10, the base substrate 10 can be prevented from contacting the surrounding magnetic body.

3 is a schematic view showing the arrangement of the voice coil and the magnetic body in operation of the flat speaker according to the embodiment of FIG. In the figure, (a) shows the case where the voice coil plate 100 is in the initial position, and (b) shows when the voice coil plate 100 has the maximum displacement.

(a) and (b), the pair of magnetic bodies 40 is constituted by a configuration in which the permanent magnets 41 having the positive and negative poles and the yoke plates 42a and 42b are disposed on the upper and lower portions thereof The upper magnetic flux area H1 between the pair of upper yoke plates 42a and the plane MC having the magnetic field strength of 0 between the pair of permanent magnets 41 in the order from the upper side to the lower side in the drawing A lower author region L2 which is lower than a plane MC having a magnetic field strength of 0 between a pair of permanent magnets 41 and a pair of lower yoke plates L1 42b of the lower magnetic pinned region H2. Here, the upper and lower yoke plates 42a and 42b may be in the form of a flat plate, but the outer portion may be formed as an oblique plane as shown in the figure. By applying such a shape, the magnetic flux uniformity and the magnetic flux density of the upper and lower magnetic flux regions H1 and H2 can be further increased. A magnetic field is formed on the upper side of the plane MC having a zero magnetic field intensity from left to right in the figure and a magnetic field is formed on the lower side in the drawing from the right side to the left side in the drawing.

(a), a current flows in a first direction (e.g., a direction protruding from the figure) to a plurality of upper transverse coils 11a, and a plurality of lower transverse coils 11b A current flows in a second direction opposite to the first direction. When a current flows through a conductor in a magnetic field, a Lorentz force is generated, which is proportional to the intensity of the magnetic field and the current. A relatively strong Lorentz force is generated in the upper and lower magnetostrictive regions H1 and H2 and the upper and lower author regions L1 and L2 Relatively weak Lorentz force occurs. That is, the force causing the displacement of the diaphragm 20 is most affected by how many upper and lower transverse coils 11a and 11b exist in the upper and lower stator regions H1 and H2.

when the diaphragm 20 is in the initial position, the lower end of the plurality of upper transverse coils 11a may be located in the upper author region L1 described above. (MC) whose magnetic field strength is 0 in the upper author region (L1).

the displacement of the diaphragm 20 and the voice coil plate 100 also increases and they move upward until they reach the position of (b). Here, the voice coil plate 100 may move until the uppermost coil 111b of the lower transverse coil 11b is positioned in the upper author region L1. Up to this time, even if some voice coil plates 100 are moved upward and some of the coils located above the plurality of upper transverse coils 11a are out of the upper exciter area H1, new upper transverse coils 11a Contribute to generating a strong Lorentz force as they enter the upper annular zone H1. At this time, the plurality of upper transverse coils 11a are arranged such that the coil at the lower end of the upper transverse coil 11a can be located close to the boundary with the upper autogenous region L1 in the upper magnetic flux area H1, And a plurality of lower transverse coils 11b are arranged such that a coil at the lower end of the plurality of lower transverse coils 11b does not overlap with the lower annular region H2, It is advantageous to arrange it so as to be located close to the boundary with the outside of the magnetic space. This is because the upper and lower magnetostrictive zones H1 and H2 having a large influence on the Lorentz force can be maximally utilized.

In other words, when a plurality of upper transverse coils 11a and a plurality of lower transverse coils 11b are distributed evenly on the voice coil plate 100 and when the voice coil plate 100 has caused maximum displacement, By arranging the voice coil so that the lower transverse coil 11a is located in the upper magnetic flux area H1 and the upper end of the lower transverse coil 11b is located in the upper author area L1, . In comparison with a conventional flat-plate-type speaker having a track-shaped voice coil having a margin between the upper transverse coil and the lower transverse coil, assuming that the height of the voice coil plate 100, that is, The output of the flat speaker with the voice coil arrangement is higher. This means that it is possible to make the flat-plate speaker that outputs the same output much thinner, which contributes greatly to downsizing and thinning of the electronic device on which the speaker is mounted.

FIG. 4 is a schematic view showing a Lorentz force acting in a maximum displacement state of the voice coil plate in the flat speaker according to the embodiment of FIG. 1; FIG. The upper magnetic flux confinement region H1 and the upper magnetic flux confinement region H2 are formed by the constitution of the pair of magnetic bodies 40 in which the respective yoke plates 42a and 42b are disposed on the upper and lower portions of the permanent magnet 41, The intensity of the magnetic field decreases or increases nonlinearly with respect to the height at the boundary between the upper author region L1 and the lower author region L2 and the lower annular region H2. This is because the upper and lower yoke plates 42a and 42b serve to close the magnetic flux.

Therefore, when the displacement of the voice coil plate is close to the maximum value as shown in FIG. 3 (b), the coils of the upper end portion of the plurality of lower lateral coils 11b are located in the upper author region L1 Even if a force f1 in a direction opposite to the moving direction of the diaphragm is generated, a large number of upper transverse coils 11a are disposed in the upper annular region H1 and a lower transverse coil 11b is arranged in the lower annular region H2 And generate large forces F1 and F2 in the same direction as the moving direction of the diaphragm, so that a large total force can be obtained as a whole.

5 is a front view showing the arrangement of the voice coil and the magnetic body in the flat speaker according to the embodiment of FIG. As shown in this figure, in the voice coil plate 100, at least a part of the vertical coil region 110C composed of vertical coils including components vertical to the diaphragm 20, more preferably, May be disposed outside the magnetic space formed by the pair of magnetic bodies 40. [ In the voice coil plate 100, when a portion of the voice coil having a longitudinal component is disposed in the magnetic field, a Lorentz force in a direction (for example, transverse direction) independent of the vibration direction of the vibration plate 20 is generated. In the ideal case, this force is not balanced with the left-hand direction and the right-hand direction components and does not affect the vibration mode of the diaphragm 20. However, when the equilibrium of the bi- directional components is broken due to manufacturing errors or deformation of the voice coil plate The vibration mode of the vibration plate 20 is unpredictably affected.

In the flat type speaker according to the present embodiment, the entire or at least a part of the vertical coil region 110C is located outside the magnetic space between the pair of magnetic bodies 40, so that the action of unnecessary force on the vibration of the diaphragm 20 Or at least reduce its effect. The arrangement of the voice coil and the magnetic body 40 may be applied together with the shape of the horizontal coil arrangement of the voice coil described above with reference to Figs. 3 to 4, or may be separately applied thereto.

10: base substrate
11: voice coil 11a: upper voice coil
11b: lower voice coil 13: base substrate corner portion
20: diaphragm 40: magnetic body
41: permanent magnet 42a: upper yoke plate
42b: lower yoke plate 100: voice coil plate
110A: upper horizontal coil region 110B: lower horizontal coil region
110C: vertical coil region H1: upper magnetic flux area
H2: Lower annulus region L1: Upper author region
L2: sub-author region

Claims

Wherein the magnetic flux density is low and the direction of the magnetic field is in the first direction and the direction of the magnetic field is in the first direction, A lower author region having a lower magnetic flux density and a second direction in which the direction of the magnetic field is opposite to the first direction and a lower magnetic domain region having a higher magnetic flux density and a magnetic field direction in the second direction , A pair of magnetic bodies;
A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And
And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space to generate a displacement within a limited range by an electromagnetic force acting on the voice coil plate,
Wherein the voice coil includes an upper lateral coil region having a plurality of upper lateral coils having a component parallel to the diaphragm and flowing in a first direction and an upper transverse coil region having a component parallel to the diaphragm, And a lower transverse coil region composed of a plurality of lower transverse coils flowing in a second direction, wherein an upper end of the lower transverse coil region is arranged to reach the upper author region when a maximum displacement of the diaphragm occurs,
Flat-panel speakers.

The method according to claim 1,
Wherein the voice coil is formed such that the lower end of the upper lateral coil region is located in the upper author region when there is no displacement of the diaphragm.
Flat-panel speakers.

The method according to claim 1,
Wherein the magnetic flux density varies non-linearly with respect to a boundary between the upper and lower autonomous region and the upper autogenous region and between the lower autogenous region and the sub-autonomous region.
Flat-panel speakers.

The method according to claim 1,
Wherein each of the pair of magnetic bodies comprises:
A permanent magnet having an anode arranged vertically; And
And upper and lower yoke plates respectively disposed on the upper surface and the lower surface of the permanent magnet,
Wherein the upper annular zone comprises a pair of upper yoke plates facing each other, the lower annular zone is between a pair of lower yoke plates facing each other, and the upper and lower author zones are facing each other And the permanent magnet is formed between the permanent magnets.
Flat-panel speakers.

The method according to claim 1,
Wherein the voice coil is disposed on both sides of the upper and lower transverse coil regions and comprises a vertical coil region constituted by vertical coils including components vertical to the diaphragm by connecting coils constituting the upper and lower transverse coil regions, Further comprising:
Characterized in that at least a part of the vertical coil region is disposed outside the magnetic space.
Flat-panel speakers.

A pair of magnetic bodies arranged at predetermined intervals to form a magnetic space;
A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And
And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space to generate a displacement within a limited range by an electromagnetic force acting on the voice coil plate,
Wherein the voice coil includes an upper lateral coil region having a plurality of upper lateral coils having a component parallel to the diaphragm and flowing in a first direction and an upper transverse coil region having a component parallel to the diaphragm, And a plurality of lower transverse coils extending from the upper end of the upper transverse coil region to a lower end of the lower transverse coil region, Characterized in that it is evenly distributed.
Flat-panel speakers.

The method of claim 6,
Wherein the voice coil is disposed on both sides of the upper and lower transverse coil regions and comprises a vertical coil region constituted by vertical coils including components vertical to the diaphragm by connecting coils constituting the upper and lower transverse coil regions, Further comprising:
Characterized in that at least a part of the vertical coil region is disposed outside the magnetic space.
Flat-panel speakers.

A pair of magnetic bodies arranged at predetermined intervals to form a magnetic space;
A voice coil plate disposed in the magnetic space and having a voice coil formed on a planar surface of the base substrate; And
And a diaphragm coupled to an upper end of the voice coil plate exposed to the outside of the magnetic space to generate a displacement within a limited range by an electromagnetic force acting on the voice coil plate,
Characterized in that the voice coil comprises a vertical coil region composed of vertical coils comprising a component perpendicular to the diaphragm and at least a part of the vertical coil region is arranged outside the magnetic space.
Flat-panel speakers.

The method of claim 8,
And the vertical coil region is entirely disposed outside the magnetic space.
Flat-panel speakers.