WO2010150953A1

WO2010150953A1 - Microspeaker

Info

Publication number: WO2010150953A1
Application number: PCT/KR2009/007324
Authority: WO
Inventors: 도성환
Original assignee: 주식회사 비에스이
Priority date: 2009-06-22
Filing date: 2009-12-08
Publication date: 2010-12-29
Also published as: CN101931844A; TW201101855A; KR20100012959U; CN201608885U; CN101931844B; TWM382684U; KR200454507Y1

Abstract

The present invention relates to a microspeaker. The microspeaker of the present invention comprises: a frame; a yoke which is fixed to the frame and has a reception groove; a permanent magnet fixed to a bottom of the reception groove of the yoke; a plate fixed to an upper surface of the permanent magnet; a diaphragm having an outer circumference fixed to the frame; and a voice coil fixed to a lower surface of the diaphragm. The microspeaker is characterized in that a chamfered surface is formed on at least one of the lateral sides of the plate and a lateral side of the yoke facing the lateral side of the plate. According to the present invention, a horizontal magnetic field region is expanded within a magnetic gap between the yoke and the plate.

Description

Micro speaker

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a micro speaker, and more particularly, to a micro speaker capable of improving the corner structure of the yoke and the plate, and extending the horizontal magnetic field lines in the magnetic gap to improve the driving force acting on the voice coil.

Speakers are generally devices that convert electrical signals into audio signals. Speakers include medium-to-large speakers that are connected to audio or amplifiers and used to amplify the volume, and are small portable devices such as mobile phones, laptops, MP3 players, and earphones. There are also small speakers for sound equipment. Such compact speakers are commonly referred to as micro speakers, and the present invention relates to such micro speakers.

A configuration of a micro speaker having a conventional general structure will be briefly described with reference to FIG. 1. 1 schematically illustrates a conventional micro speaker 100 as a cross-sectional perspective view.

The conventional micro speaker 100 includes a frame 101, a yoke 102, a permanent magnet 103, a plate 104, a voice coil 105, and a diaphragm 106. Although not shown in FIG. 1, a cover is normally coupled to the upper portion of the frame 101.

The frame 101 is a member forming the external shape of the micro speaker, and a vent hole (not shown) is formed at one side. The diaphragm 106 is divided into an inner portion 107 and an outer portion 109 based on the boundary portion 108. The upper end of the voice coil 105 formed by winding the conductor is bonded to the lower surface of the boundary portion 108 of the diaphragm 106. A part (not shown) of the remaining conductor wire wound on the voice coil 105 is exposed to the outside of the frame 101 and is electrically connected to an external power source.

The downwardly extending portion of the voice coil 105 is located in a magnetic gap, which is a space formed between the plate 104 and the inner wall of the yoke 102. At this time, when a current signal including several frequencies is applied to the voice coil 105, the mechanical coil is generated in the voice coil 105 by interaction with the magnetic field according to the strength of the current and the magnitude of the frequency, the up-down direction Movement occurs. Then, the vibration plate 106 to which the voice coil 105 is attached also moves up and down, and vibration is generated. As a result, a sound pressure having a predetermined magnitude that a human ear can recognize is generated.

In Fig. 2, the flow of magnetic force lines is schematically represented. 2 shows only a part of the yoke 102, the permanent magnet 103, the plate 104, and the voice coil 105 in cross-sectional view. In the case of the conventional micro speaker 100 having such a conventional structure, the line of magnetic force M generated in the permanent magnet 103 exits the space through the plate 104 and then enters the yoke 102 and the permanent magnet 103 again. Configure the magnetic circuit back to).

However, in the surfaces of the plate 104 and the yoke 102 that face each other, the yoke surface does not have a structure in which the yoke surface is symmetrical with respect to the plate. 102) The shape of the lines of magnetic force M entering the top and sides of the corners is undesirable. That is, the area in which the magnetic force line M penetrating the voice coil 105 maintains the horizontal state is not large, and the symmetry of the magnetic field between the upper and lower portions of the magnetic circuit is reduced.

In addition, since the Lorentz force generated by the magnetic force lines M and the current flowing through the voice coil 105 react with each other acts in various directions, the voice coil 105 vibrates non-vertically, resulting in an increase in the distortion rate. In some cases, the voice coil 105 may collide with the plate 104 or the yoke 102 and may be damaged.

SUMMARY OF THE INVENTION An object of the present invention is to provide a micro-speaker which solves the above-mentioned problems and improves the driving force of the voice coil by expanding the horizontal magnetic field line region in the magnetic gap between the yoke and the plate.

The present invention has been made to solve the above problems, the micro speaker according to the present invention, a frame, a yoke fixed to the frame and having a receiving groove (yoke), and fixed to the bottom surface of the receiving groove of the yoke A permanent magnet, a plate fixed to an upper surface of the permanent magnet, a diaphragm fixed to an outer circumference of the permanent magnet, and a voice coil fixed to a lower surface of the diaphragm, wherein the plate faces each other. It is characterized in that the chamfered surface is formed on the upper end of at least one side of the side and the side of the yoke.

On the other hand, the chamfering surface is a yoke chamfering surface formed on the upper portion of the yoke, the yoke chamfering surface, in the vertical cross-sectional view along the imaginary surface passing through the center of the plate, the side of the yoke in the upper surface of the yoke And an arbitrary first point located between a horizontal minimum point equal to 1/4 of the yoke thickness and a horizontal maximum point equal to 3/4 from an imaginary yoke contact extending from the virtual yoke contact with the upper surface, and on the side of the yoke. It is preferably formed along a straight line connecting an arbitrary second point located between the vertical minimum point, which is 1/4 of the yoke thickness, and the vertical maximum point, which is 1/4 of the yoke thickness, from the virtual yoke contact downward.

On the other hand, the chamfering surface is a plate chamfering surface formed on the upper portion of the plate, the plate chamfering surface, in the vertical cross-sectional view along the imaginary surface passing through the center of the plate, in the upper surface of the plate, the side of the plate And an arbitrary third point located between the horizontal minimum point, which is 1/4 of the plate thickness and the horizontal maximum point, which is 3/4, from the imaginary plate contact where the upper surface is extended and meets, and on the side of the plate. It is preferably formed along a straight line connecting an arbitrary fourth point located between the vertical minimum point that is 1/4 of the plate thickness and the vertical maximum point that is 3/4, in the downward direction from the virtual plate contact.

On the other hand, it is preferable that the said chamfer surface contains the plate chamfer surface formed in the said plate, and the yoke chamfer surface formed in the said yoke.

The yoke chamfering surface has a yoke thickness in an outward direction from an imaginary yoke contact in which the side surface and the upper surface of the yoke extend and meet on the upper surface of the yoke in a vertical cross-sectional view along an imaginary surface passing through the center of the plate. An arbitrary first point located between a horizontal minimum point equal to 1/4 of and a horizontal maximum point equal to 3/4 of the yoke, and at the side of the yoke, downward of the yoke thickness from the virtual yoke contact. And formed along a straight line connecting an arbitrary second point located between a vertical minimum point of 4 and a vertical maximum point of 3/4, wherein the plate chamfering surface, in the upper surface of the plate, Located between the horizontal minimum point that is 1/4 of the plate thickness and the horizontal maximum point that is 3/4 from the imaginary plate contact where the upper surface is extended An arbitrary third point and an arbitrary third position located on the side of the plate between the vertical minimum point, which is 1/4 of the plate thickness and the vertical maximum point, which is 3/4, downward from the imaginary plate contact; It is preferably formed along a straight line connecting four points.

The plate chamfer surface and the yoke chamfer surface are preferably mutually symmetrical with respect to an imaginary vertical line across the midpoint of the two facing sides.

The first point is a point at which the yoke thickness is 1/2 from the virtual yoke contact to the outside, and the second point is at a half of the yoke thickness downward from the virtual yoke contact. It is preferable that it is a point.

According to the micro-speaker of the present invention, the horizontal magnetic field line region in the magnetic gap between the yoke and the plate is expanded to improve the driving force of the voice coil, the magnetic field symmetry of the upper and lower plates is improved to improve the distortion rate of the diaphragm, and The effect that the vibration in the non-vertical direction of the diaphragm is reduced can be obtained.

1 is a schematic cross-sectional perspective view of a conventional micro speaker,

2 is a schematic flow of the magnetic force line of FIG.

3 is a schematic cross-sectional perspective view of a micro speaker of one embodiment according to the present invention;

4 and 5 are cross-sectional views of the main part of the yoke and the plate of the micro speaker of FIG.

6 is a schematic cross-sectional view of a micro speaker of another embodiment according to the present invention;

7 is a schematic cross-sectional view of a micro speaker of another embodiment according to the present invention;

A micro speaker of an embodiment according to the present invention will be described with reference to FIGS. 3 to 5.

FIG. 3 is a schematic perspective view showing a cross section of the micro speaker 1 of the embodiment according to the present invention, and FIGS. 4 and 5 are yokes 20 having the features of the present invention in the configuration of the micro speaker 1 of FIG. ) And only the main part such as the plate 40 is shown in cross section.

The micro speaker 1 of the present embodiment includes a frame 10, a yoke 20 fixed to the frame 10 and having a receiving groove, and a permanent magnet fixed to the bottom surface of the receiving groove of the yoke 20. 30, a plate 40 fixed to the upper surface of the permanent magnet 30, a diaphragm 50 having its outer circumference fixed to the frame 10, and an upper end thereof fixed to the lower surface of the diaphragm 50. It is comprised including the voice coil 60 which became.

The present invention is an invention having the characteristics in the shape of the yoke 20 and the plate 40, the rest of the configuration is similar to the conventional conventional configuration, so the description thereof will be omitted, in the following configuration of the features of the present invention Only in detail.

In the micro speaker 1 of the present embodiment, the yoke chamfered surface 24 and the plate chamfered surface (the upper end of the side surface 22 of the yoke 20 facing each other and the upper end of the side surface 42 of the plate 40 respectively) 44) is formed.

4 and the yoke 20 of FIG. 4, which are vertical cross-sectional views along the imaginary plane passing through the center of the plate 40 of the micro speaker 1, with respect to the yoke chamfer surface 24 and the plate chamfer surface 44. Only the plate 40 is described in detail with reference to FIG. 5.

Yoke 20 has a bottom member and sidewalls extending upwardly along the circumference of the bottom member. A chamfer 24 is formed on top of the inner side 22 of the side wall. The yoke chamfered surface 24 is formed in the part where the side surface 22 and the upper surface 23 meet.

Referring to FIG. 5, the yoke chamfered surface 24 is located on the upper surface 23 of the yoke 20 from the virtual yoke contact Y1 where the side surface 22 and the upper surface 23 of the yoke extend and meet. An arbitrary first point A1 located between the horizontal minimum point Y2, which becomes 1/4 of the yoke thickness Yt in the direction, and the horizontal maximum point Y3, which becomes 3/4;

On the side surface 22 of the yoke 20, the vertical minimum point Y4 equal to 1/4 of the yoke thickness Yt and the vertical maximum point equal to 3/4 downward from the virtual yoke contact Y1. It is formed along a straight line connecting any second point A2 located between (Y5). In other words, the yoke chamfered surface 24 is formed three-dimensionally along the sidewall of the yoke 20 along a straight line connecting the first point A1 and the second point A2 defined in the cross-sectional view.

The plate chamfered surface 44 is provided in the upper part of the side surface 42 of the plate 40. The plate chamfered surface 44 is formed in the part where the side surface 42 and the flat upper surface 43 meet.

The plate chamfered surface 44 is a plate inward from the imaginary plate contact point P1 where the side surface 42 and the upper surface 43 of the plate 40 extend and meet on the upper surface 43 of the plate 40. An arbitrary third point A3 located between the horizontal minimum point P2, which is 1/4 of the thickness Pt, and the horizontal maximum point P3, which is 3/4;

On the side surface 42 of the plate 40, in the downward direction from the plate contact point P1, the vertical minimum point P4, which is 1/4 of the plate thickness Pt, and the vertical maximum point P5, which is 3/4, It is formed along a straight line connecting any fourth point (A4) located between the).

That is, the plate chamfered surface 44 is formed three-dimensionally along the outer peripheral part of the plate 40 along the straight line which connected the 3rd point A3 and the 4th point A4 defined in sectional drawing.

In the case of this embodiment, the plate chamfer 44 and the yoke chamfer 24 are mutually symmetrical with respect to the imaginary vertical line C across the midpoint of the two facing

sides

42 and 22. In other words, the chamfered surfaces 44 and 24 on both sides have the same angle and area.

In the present embodiment, the first point A1 of the yoke chamfered surface 24 is a point that becomes 1/2 of the yoke thickness from the virtual yoke contact Y1 in the outward direction, and the second point A2. Is the point which becomes 1/2 of the thickness of a yoke in the downward direction from the virtual yoke contact Y1. In addition, the plate chamfered surface 44 is also a point that becomes half of the plate thickness, and when the thickness is the same as the yoke, the plate chamfer surface 44 has a symmetrical shape.

According to the microspeaker 1 having the above-described configuration, by providing the chamfered surfaces 24 and 44 at the upper end portions of the yoke and the plate facing each other, the effect of extending the horizontal magnetic field lines in the magnetic gap can be obtained.

That is, in the case of the conventional micro speaker, since the upper end of the yoke and the plate is formed at almost right angles, the horizontality in the magnetic gap of the magnetic force lines constituting the magnetic circuit is not sufficiently secured, and the symmetry of the magnetic field of the upper and lower plates is not sufficient. I couldn't. For this reason, the driving force which moves a voice coil becomes weak, and there existed a problem which a non-vertical movement generate | occur | produces.

However, in the case of the present invention, by providing the chamfer surface (24, 44) in the yoke and the plate, respectively, to solve the above-mentioned conventional problem, the horizontal magnetic field line region in the magnetic gap is expanded, the symmetry of the magnetic field of the upper and lower plates This was improved.

In addition, this improves the driving force of the voice coil and reduces the vibration in the non-vertical direction, thereby improving the distortion rate of the diaphragm, and the yoke and the plate of the voice coil yoke generated by the twisting vibration caused by the rocking mode of the voice coil. The effect of reducing the scratch shape with the inner wall can be obtained.

On the other hand, in the case of the micro speaker 1 of the above-described embodiment, since the first point and the second point are separated by the same distance from the virtual yoke contact Y1, the yoke chamfered surface 24 is separated from the center vertical line C. Although it forms an angle of 45 degrees, this invention is not limited to this. That is, in another embodiment, when the first point and the second point become various points within the above-described limited range, the angle between the chamfered surface and the center vertical line C may also have various values other than 45 °. The area of the chamfer will also vary.

However, the position of the first point A1 is less than 1/4 or greater than 3/4 of the yoke thickness from the contact Y1, or the position of the second point A2 is of the yoke thickness from the contact Y1. If the chamfer surface becomes too small or too large when the position becomes smaller than 1/4 or larger than 3/4, i.e., outside the requirements set out, the shape of the magnetic force line does not become the desired desired shape. Point A1 and second point A2 must meet the above requirements.

The plate chamfered surface 44 is also similar to the yoke chamfered surface 24, and in other embodiments, the third and fourth points A3 and A4 may be changed to various positions within the requirements. It is deformable to have an area.

On the other hand, in the present embodiment, the yoke chamfered surface 24 and the plate chamfered surface 44 are illustrated in a plane. However, the present invention is not limited thereto, and according to an exemplary embodiment, the chamfered surface may be a smoothly convex curved surface. That is, the line connecting the first and second points or the line connecting the third and fourth points may be a convex arc instead of a straight line.

In the present embodiment, the yoke chamfered surface 24 and the plate chamfered surface 44 are symmetrical with respect to the center line C, but the present invention is not limited thereto. That is, in another embodiment, the shape of the yoke chamfer surface and the shape of the plate chamfer surface may not be symmetrical with respect to the mutual center line (C).

In addition, in the present embodiment, the chamfered surface is formed on both sides of the yoke and the plate, but the present invention is not limited thereto. That is, the chamfer surface may be formed only in one of the yoke and the plate.

6 and 7 show a modified embodiment in which a chamfer is formed only on the yoke and the flake, respectively.

That is, in Fig. 6, the embodiment in which the chamfered surface 24a is formed only in the yoke 20 is shown in cross section. Since the description of the chamfered surface 24a is the same as the description of the first embodiment described above, further description is omitted.

In FIG. 7, the embodiment in which the chamfered surface 44a is formed only on the plate 40 is shown in cross section. Since the description of the chamfered surface 44a is the same as the description of the first embodiment described above, further description is omitted.

Claims

A frame, a yoke fixed to the frame and having a receiving groove, a permanent magnet fixed to a bottom surface of the receiving groove of the yoke, a plate fixed to an upper surface of the permanent magnet, and to the frame In the micro speaker comprising a diaphragm fixed to the outer peripheral portion and a voice coil fixed to the lower surface of the diaphragm,

And a chamfered surface is formed at an upper end of at least one side of the side of the plate and the side of the yoke that face each other.
The method of claim 1,

The chamfered surface is a yoke chamfered surface formed on the upper portion of the yoke,

The yoke chamfered surface,

In the vertical section along the imaginary plane passing through the center of the plate,

On the upper surface of the yoke, an arbitrary position located between the horizontal minimum point that is 1/4 of the yoke thickness and the horizontal maximum point that is 3/4 from the imaginary yoke contact where the side and the upper surface of the yoke extend and meet in the outward direction. The first point,

On the side of the yoke, a straight line connecting a second point located downwards from the virtual yoke contact point between a vertical minimum point that is 1/4 of the yoke thickness and a vertical maximum point that is 3/4. Micro speaker, characterized in that formed along.
The method of claim 1,

The chamfered surface is a plate chamfered surface formed on the upper portion of the plate,

The plate chamfer surface,

In the vertical section along the imaginary plane passing through the center of the plate,

On the upper surface of the plate, any position located between the horizontal minimum point that is 1/4 of the plate thickness and the horizontal maximum point that is 3/4 inward from the virtual plate contact where the side and the upper surface of the plate extend and meet. The third point,

On the side of the plate, a straight line connecting downwards from the imaginary plate contact connecting any fourth point located between a vertical minimum point of 1/4 of the plate thickness and a vertical maximum point of 3/4 of the plate thickness. Micro speaker, characterized in that formed along.
The method of claim 1,

The chamfering surface, the plate chamfering surface formed on the plate and the yoke chamfering surface formed on the yoke.
The method of claim 4, wherein

The yoke chamfered surface,

In the vertical section along the imaginary plane passing through the center of the plate,

On the upper surface of the yoke, an arbitrary position located between the horizontal minimum point that is 1/4 of the yoke thickness and the horizontal maximum point that is 3/4 from the imaginary yoke contact where the side and the upper surface of the yoke extend and meet in the outward direction. The first point,

On the side of the yoke, a straight line connecting a second point located downwards from the virtual yoke contact point between a vertical minimum point that is 1/4 of the yoke thickness and a vertical maximum point that is 3/4. Formed along

The plate chamfer surface,

On the upper surface of the plate, any position located between the horizontal minimum point that is 1/4 of the plate thickness and the horizontal maximum point that is 3/4 inward from the virtual plate contact where the side and the upper surface of the plate extend and meet. The third point,

On the side of the plate, a straight line connecting downwards from the imaginary plate contact connecting any fourth point located between a vertical minimum point of 1/4 of the plate thickness and a vertical maximum point of 3/4 of the plate thickness. Micro speaker, characterized in that formed along.
The method of claim 5,

And the plate chamfer surface and the yoke chamfer surface are mutually symmetrical with respect to an imaginary vertical line crossing the midpoint of the two facing sides.
The method of claim 6,

The first point is a point that becomes 1/2 of the yoke thickness in the outward direction from the virtual yoke contact, and the second point is a point that becomes 1/2 of the yoke thickness in the downward direction from the virtual yoke contact. Micro speaker, characterized in that.