KR102383169B1 - Voice coil motor - Google Patents

Abstract

The voice coil motor includes a base unit; a movable member disposed on the base unit to support the lens, the bobbin having a plurality of rotation preventing parts intermittently formed along the outer circumferential surface, and a first driving unit disposed on the outer circumferential surface of the bobbin; a stator including a yoke fixed to the base unit and surrounding the movable member and including an inner yoke part extending between the rotation preventing parts, and a second driving part disposed to face the first driving part; an elastic member elastically supporting the movable member with respect to the stator; and a foreign material generation suppressing unit for preventing foreign material from being generated from the bobbin by reducing a contact area between the rotation preventing unit and the inner yoke unit.

Description

Voice coil motor {VOICE COIL MOTOR}

The present invention relates to a voice coil motor.

Recently, a camera module including an image sensor capable of storing a digital image or moving picture of a subject is mounted in portable communication devices such as mobile phones, game consoles, and tablet PCs.

In the conventional camera module, it is difficult to adjust the distance between the image sensor and the lens disposed in front of the image sensor, so it is difficult to accurately set the focus on the subject, so the quality of digital images or moving pictures is deteriorated.

With the recent development of voice coil motor (VCM) technology, the distance between the image sensor and the lens can be adjusted, making it possible to acquire better digital images or moving pictures.

In order to drive the voice coil motor, a stator including a magnet and a yoke, a mover including a coil block disposed inside the stator and disposed on the outer peripheral surface of a bobbin equipped with a lens to generate electromagnetic force by a driving current applied from the outside and a cover disposed on the stator to cover the mover.

The conventional voice coil motor includes a technology to prevent the bobbin from rotating abnormally by making a part of the bobbin catch on the yoke, but as the bobbin comes into contact with the yoke, foreign substances are generated from the bobbin It has a problem in that the display quality of an image or video is deteriorated by being disposed on the back.

(Patent Document 1) KR10-2012-0065492 A

The present invention provides a voice coil motor that reduces or suppresses the generation of foreign substances from the bobbin when the bobbin is in contact with the yoke to prevent deterioration of display quality of images or moving pictures.

The technical problems to be achieved by the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned can be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be.

In one embodiment, the voice coil motor includes a base unit; a movable member disposed on the base unit to support the lens, the bobbin having a plurality of rotation preventing parts intermittently formed along the outer circumferential surface, and a first driving unit disposed on the outer circumferential surface of the bobbin; a stator including a yoke fixed to the base unit and surrounding the movable member and including an inner yoke part extending between the rotation preventing parts, and a second driving part disposed to face the first driving part; an elastic member elastically supporting the movable member with respect to the stator; and a foreign material generation suppressing unit for preventing foreign material from being generated from the bobbin by reducing a contact area between the rotation preventing unit and the inner yoke unit.

According to the voice coil motor according to the present invention, the contact area of the inner yoke portion of the yoke that is in contact with the rotation prevention portion of the bobbin and the rotation prevention portion of the bobbin is reduced so that the rotation prevention portion of the bobbin and the inner yoke portion come into contact with the rotation prevention portion from the By reducing or suppressing the generation of foreign substances, it is possible to prevent deterioration of image or video quality.

1 is a cross-sectional view of a voice coil motor according to an embodiment of the present invention.
FIG. 2 is an enlarged view of part 'A' of FIG. 1 .
3 is a side view of the bobbin of FIG. 1 ;
4 is a perspective view of a bobbin according to another embodiment of FIG. 3 .

Hereinafter, an embodiment according to the present invention will be described in detail with reference to the accompanying drawings. In this process, the size or shape of the components shown in the drawings may be exaggerated for clarity and convenience of explanation. In addition, terms specifically defined in consideration of the configuration and operation of the present invention may vary depending on the intention or custom of the user or operator. Definitions of these terms should be interpreted as meanings and concepts consistent with the technical idea of the present invention based on the contents throughout this specification.

1 is a cross-sectional view of a voice coil motor according to an embodiment of the present invention. FIG. 2 is an enlarged view of part 'A' of FIG. 1 . 3 is a side view of the bobbin of FIG. 1 ;

1 to 3 , the voice coil motor 600 includes a base unit 100 , a mover 200 , a stator 300 , an elastic member 400 , and a foreign material generation suppressor 500 .

The base unit 100 is formed in the shape of a rectangular parallelepiped plate, and a through hole 110 penetrating through the upper surface of the base unit 100 and the lower surface opposite to the upper surface is formed in the central portion of the base unit 100 .

At the four corners formed on the upper surface of the base unit 100, coupling posts 120 protrude, respectively, and the coupling posts 120 are coupled to a spacer 330 to be described later.

The mover 200 includes a bobbin 210 and a first driving unit 220 .

The bobbin 210 is formed in a cylindrical shape with upper and lower surfaces opened, and a female screw part 212 for mounting at least one lens having a cylindrical shape may be formed on an inner surface of the bobbin 210 .

A plurality of rotation prevention parts 213 protrude from the outer peripheral surface 211 of the bobbin 210 along the outer peripheral surface 211 of the bobbin 210 , and each rotation prevention part 213 has an outer peripheral surface 211 of the bobbin 210 . In, for example, four are formed equally spaced.

The rotation preventing unit 213 is caught by the inner yoke portion 323 of the yoke 320 to be described later to prevent rotation of the bobbin 210 .

Although a plurality of rotation preventing parts 213 protruding at equal intervals from the outer circumferential surface 211 of the bobbin 210 are shown and described in the embodiment of the present invention, differently from this, the rotation preventing part formed on the bobbin 210 . Reference numeral 213 may be formed in the shape of a recess concave from the outer peripheral surface 211 of the bobbin 210 .

The first driving unit 220 is formed by winding a long wire insulated by an insulating resin in a cylindrical shape, and the first driving unit 220 is to be adhered to the surface of the rotation preventing unit 213 of the bobbin 210 by an adhesive. can

The stator 300 includes a second driving unit 310 and a yoke 320 . In addition, the stator 300 may further include a spacer 330 .

In an embodiment of the present invention, the second driving unit 310 is disposed outside the first driving unit 220 , and the second driving unit 310 is disposed to face the first driving unit 220 .

The second driving unit 310 includes, for example, four magnets having a column shape, and the four second driving units 310 are formed around the first driving unit 220 at equal intervals.

The yoke 320 is formed in the shape of a square plate and extends from the four edges of the yoke top plate 321 and the yoke top plate 321 having a circular opening in the center, and includes the yoke side plate 322 surrounding the mover 100. do.

Among the yoke side plates 322 of the yoke 320 , the second driving unit 310 is disposed at inner corners formed by a pair of adjacent yoke side plates 322 , respectively.

An inner yoke part 323 extending between the rotation preventing parts 213 of the bobbin 210 from the opening of the yoke top plate 321 is formed on the yoke top plate 321 .

The inner yoke unit 323 is a rotation preventing unit 213 when the bobbin 210 is rotated by the leakage of the electromagnetic field generated from the first driving unit 220 and the rotational force generated when the lens is mounted on the bobbin 210 . It comes into contact with and serves to prevent rotation of the bobbin 210 .

The elastic member 400 is disposed on the lower surface of the bobbin 210 of the mover 200 . In one embodiment of the present invention, the elastic member 400, for example, is made of a pair, each elastic member 400 is electrically insulated from each other.

The pair of elastic members 400 includes an inner elastic part 410 , an outer elastic part 420 , and a connection elastic part 430 .

The outer elastic part 420 is formed in a bent band shape when viewed in a plan view, and the outer elastic part 420 is inserted into a pair of adjacent coupling posts 120 of the base unit 100 and the coupling posts 120 . ) is bound to

The inner elastic part 410 is disposed on the lower surface of the bobbin 210 . Accordingly, the inner elastic part 410 is formed in a curved band shape similar to the shape of the lower surface of the bobbin 210 .

The connection elastic part 430 is formed in a zigzag shape when viewed in a plan view, and the connection elastic part 430 is connected to the inner elastic part 410 and the outer elastic part 420 .

Referring back to FIG. 1 , an additional elastic member 450 for elastically supporting the bobbin 210 is disposed on the upper surface opposite to the lower surface of the bobbin 210 .

The spacer 330 serves to fix the elastic member 400 , the additional elastic member 450 , the mover 200 , and the stator 300 .

The spacer 330 includes an upper spacer 332 and a lower spacer 335 , the upper spacer 332 and the lower spacer 335 are engaged with each other, and the lower spacer 335 is coupled to the base unit 100 . It is coupled to the pillar (120).

The outer elastic part 420 of the elastic member 400 is fixed between the lower spacer 335 and the upper surface of the base unit 100 , and the additional elastic member 450 is fixed to the lower surface of the upper spacer 332 .

The cover 550 includes a cover top plate 560 formed in a rectangular plate shape having a circular opening for exposing a lens, and a cover side plate 570 extending from the edge of the cover top plate 560, and the cover side plate 570 ) is coupled to the base unit 100 .

2 and 3 , when a lens is coupled to the bobbin 210 or when the bobbin 210 is up-down, a rotational force is applied to the bobbin 210 , and the bobbin 210 is caused by the rotational force applied to the bobbin 210 . ) is rotated in the horizontal direction, and when the bobbin 210 is rotated, shape deformation or distortion of the elastic member 400 and the additional elastic member 450 occurs, so that the optical axis of the mover 100 is misaligned or the mover ( 100), driving failure occurs.

The rotation of the bobbin 210 is prevented by the rotation preventing part 213 formed on the outer peripheral surface of the bobbin 210 and the inner yoke part 323 of the yoke 320, the inner yoke part 323 and the rotation preventing part When the 213 is in contact, a fine foreign material may be generated from the bobbin 210 which is an injection product, and the fine foreign material may fall and be introduced into the upper surface of the IR filter disposed on the rear surface of the base unit 100 .

When a fine foreign material generated from the bobbin 210 is disposed on the IR filter, the quality of a digital image or video may be deteriorated due to the foreign material.

In one embodiment of the present invention, the voice coil motor 600 generates foreign substances to prevent foreign substances from being generated by the contact between the rotation prevention part 213 of the bobbin 210 and the inner yoke part 323 of the yoke 320 . It includes a suppression unit (500).

The foreign material generation suppression unit 500, for example, by reducing the contact area between the rotation preventing unit 213 of the bobbin 210 and the inner yoke unit 323 of the yoke 320, the rotation preventing unit of the bobbin 210 (213) to reduce or suppress the amount of foreign matter generated.

The foreign material generation suppression unit 500 faces both side surfaces of the inner yoke unit 323 and is formed on each side surface 213a of the rotation preventing unit 213 in contact with the inner yoke unit 323 .

In particular, the foreign material generation suppression unit 500 formed on the side surfaces 213a facing both sides of the inner yoke unit 323 is formed from the rotation prevention unit 213 to reduce the amount of foreign matter generated from the rotation prevention unit 213 . It is formed in a stepped shape extending outward.

Specifically, when both side surfaces of the inner yoke unit 323 are formed in a straight shape, a first gap is formed between the side surfaces of the rotation preventing unit 213 and the side surfaces of the inner yoke unit 323 , and foreign matter is generated. A second gap larger than the first gap is formed between the side surfaces of the suppression part 500 and the inner yoke part 323 .

Accordingly, when the bobbin 210 is rotated, the side surfaces of the inner yoke unit 323 come into contact with the respective side surfaces 213a of the rotation preventing unit 213 having a reduced area, thereby causing foreign substances caused by the rotation preventing unit 213 . It is possible to reduce or suppress the amount of occurrence.

In addition, considering that the bobbin 210 is injection-molded, the foreign material generation suppression unit 500 may be formed to a predetermined depth from the upper surface of the bobbin 210 .

On the other hand, although injection molding is more difficult, in order to further reduce the contact area between the rotation prevention part 213 and the inner yoke part 323 of the bobbin 210, the foreign material generation inhibiting part 500 is at least in the rotation prevention part 213. It is okay even if two are intermittently formed.

Referring to FIG. 4 , even if the amount of foreign matter generated by the contact between the rotation preventing unit 213 and the inner yoke unit 323 due to the rotation of the bobbin 210 is reduced or suppressed through the foreign material generation suppressing unit 500 , a trace amount of foreign matter This may occur, in one embodiment of the present invention, in order to prevent a small amount of foreign matter generated through the rotation preventing unit 213 from flowing into the IR filter, etc., on the bottom surface formed by the rotation preventing unit 213 A foreign material adsorption member 590 may be disposed.

The foreign material adsorbing member 590 may include, for example, a synthetic resin having sufficient viscosity to collect the foreign material, and the foreign material adsorbing member 590 may include an epoxy resin having viscosity.

Although in one embodiment of the present invention, in order to prevent foreign substances generated from the rotation preventing unit 213 of the bobbin 210, a recessed foreign material generation suppressing unit 500 is formed in the rotation preventing unit 213 of the bobbin 210. Although it is shown and described to reduce or suppress the generation of foreign substances from the rotation prevention unit 213 by forming a A portion of the portion 323 may be cut and cut to reduce the contact area with the rotation preventing portion 213 .

As described in detail above, the contact area of the inner yoke portion of the yoke that is in contact with the rotation prevention portion of the bobbin and the rotation prevention portion of the bobbin is reduced, thereby generating from the rotation prevention portion when the rotation prevention portion of the bobbin and the inner yoke portion are in contact. By reducing or suppressing the generation of foreign substances, it is possible to prevent deterioration of image or video quality.

Although the embodiments according to the present invention have been described above, these are merely exemplary, and those of ordinary skill in the art will understand that various modifications and equivalent ranges of embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

600...voice coil motor 100...base unit
200...Movers 300...Stators
400...Elastic member 500...Foreign matter generation suppression part

Claims (20)

a yoke including an upper plate, a side plate extending from an outer edge of the upper plate, and an inner yoke part extending from an inner edge of the upper plate;
a base unit coupled to the side plate of the yoke;
a bobbin disposed within the yoke and disposed on the base unit;
a coil disposed on the bobbin;
a magnet disposed between the coil and the side plate of the yoke; and
It includes an upper elastic member coupled to the upper surface of the bobbin,
The bobbin includes a first outer circumferential surface and a plurality of rotation preventing portions protruding from the first outer circumferential surface,
Each of the plurality of rotation preventing parts includes a second outer circumferential surface facing the same direction as the first outer circumferential surface,
The coil is disposed on the second outer peripheral surface of the anti-rotation part,
At least a portion of the inner yoke portion is disposed between the plurality of rotation preventing portions,
At least one of the plurality of rotation preventing parts includes a first surface connecting the first outer peripheral surface and the second outer peripheral surface,
The first surface of the rotation preventing unit faces the same direction as the upper surface of the bobbin and is disposed at a lower position than the upper surface of the bobbin. The method of claim 1,
The bobbin may include a foreign material suppressing part formed between the upper surface of the bobbin and the first surface of the rotation preventing part. The method of claim 1,
and the bobbin includes a recess recessed from the upper surface of the bobbin to the first surface of the anti-rotation part so as to reduce a contact area between the rotation prevention part and the inner yoke part of the bobbin. According to claim 1,
At least one of the plurality of anti-rotation parts includes a second surface extending downward from the first surface and connecting the first outer peripheral surface and the second outer peripheral surface,
The second surface is a voice coil motor facing the inner yoke unit. 5. The method of claim 4,
When the bobbin rotates, the inner yoke portion is in contact with the second surface of the rotation preventing portion of the voice coil motor. The method of claim 1,
The at least a portion of the inner yoke part is disposed between the plurality of rotation prevention parts so as to be caught by the rotation prevention part to prevent rotation of the bobbin. According to claim 1,
The coil is disposed on the second outer circumferential surface of the anti-rotation part so that a space is formed between the coil and the first outer circumferential surface of the bobbin,
The at least part of the inner yoke part is disposed in the space between the coil and the first outer peripheral surface of the bobbin. According to claim 1,
The first surface of the rotation preventing part is spaced apart from the upper elastic member of the voice coil motor. 3. The method of claim 2,
The foreign material generation suppression portion is formed to reduce the contact area between the rotation prevention portion and the inner yoke portion,
A voice coil motor in which a portion of the inner yoke portion overlaps in a direction perpendicular to the optical axis direction and a space formed by the foreign material generation suppressing portion. The method of claim 1,
wherein the bobbin includes a protrusion protruding from the second outer circumferential surface of the rotation preventing unit and disposed under the coil. 4. The method of claim 3,
The inner yoke part includes a side facing the side of the rotation preventing part,
A first gap is formed between the side surface of the rotation preventing part and the side surface of the inner yoke part, and a second gap is formed between the side surface of the recess and a side surface between the inner yoke part,
The second gap is larger than the first gap of the voice coil motor. 12. The method of claim 11,
It includes a foreign material adsorption member disposed between the plurality of rotation preventing parts,
The foreign material adsorption member is a voice coil motor comprising an epoxy resin having a viscosity. According to claim 1,
A voice coil motor in which the plurality of rotation preventing units are integrally formed with the bobbin. a yoke including an upper plate, a side plate extending from an outer edge of the upper plate, and a plurality of inner yoke parts extending from an inner edge of the upper plate;
a base unit coupled to the side plate of the yoke;
a bobbin disposed within the yoke and disposed on the base unit;
a coil disposed on the bobbin;
a magnet disposed between the coil and the side plate of the yoke; and
It includes an upper elastic member coupled to the upper surface of the bobbin,
The bobbin includes a first outer circumferential surface and a rotation preventing portion protruding from the first outer circumferential surface,
The rotation preventing part includes a second outer peripheral surface facing the same direction as the first outer peripheral surface, and a first surface connecting the first outer peripheral surface and the second outer peripheral surface,
The coil is disposed on the second outer peripheral surface of the anti-rotation part,
At least a portion of the inner yoke portion is disposed between the coil and the first outer peripheral surface of the bobbin,
The rotation preventing part is disposed between the plurality of inner yoke parts,
The first surface of the rotation preventing unit faces the same direction as the upper surface of the bobbin and is disposed at a lower position than the upper surface of the bobbin. 15. The method of claim 14,
The bobbin may include a foreign material suppressing part formed between the upper surface of the bobbin and the first surface of the rotation preventing part. 15. The method of claim 14,
and the bobbin includes a recess recessed from the upper surface of the bobbin to the first surface of the anti-rotation part so as to reduce a contact area between the rotation prevention part and the inner yoke part of the bobbin. 15. The method of claim 14,
The rotation preventing portion includes a second surface extending downward from the first surface and connecting the first outer peripheral surface and the second outer peripheral surface,
When the bobbin rotates, the inner yoke portion is in contact with the second surface of the rotation preventing portion of the voice coil motor. 15. The method of claim 14,
The first surface of the rotation preventing part is spaced apart from the upper elastic member of the voice coil motor. The voice coil motor of any one of claims 1 to 18;
a lens coupled to the bobbin of the voice coil motor; and
A camera module containing an image sensor. A mobile phone comprising the camera module of claim 19.

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