KR102345969B1 - Voice coil motor - Google Patents

Abstract

The voice coil motor includes a stator including a first driving unit; a mover disposed inside the stator and including a second driving unit for generating a second magnetic field moved from the stator by the first magnetic field generated from the first driving unit; a base for fixing the stator; and a first elastic member coupled to a lower portion of the mover and opposite to the lower portion of the mover to maintain the mover spaced apart from the base when a driving signal is not applied to any one of the first and second driving units and an elastic member including a second elastic member coupled to the upper part, and in order to prevent tilt of the movable member by the center of gravity of the movable member, the first and second elastic members have different spring constants (K). have

Description

Voice coil motor {VOICE COIL MOTOR}

The present invention relates to a voice coil motor.

Recently, a mobile phone having a built-in micro digital camera has been developed.

In the case of a miniature digital camera applied to a conventional mobile phone, etc., it was not possible to adjust the distance between the image sensor and the lens that converts external light into a digital image or digital image. With the development of the same lens driving device, it is possible to obtain an improved digital image or digital image from a miniature digital camera.

In general, the voice coil motor has a lens mounted therein, and a bobbin disposed on the base moves upward from the base to adjust the distance between the lens and the image sensor disposed on the rear side of the base.

In addition, a leaf spring is coupled to the bobbin of the voice coil motor so that the bobbin is always in contact with the base by the elastic force of the leaf spring when the voice coil motor is not operating. That is, the bobbin of the conventional voice coil motor is driven in one direction toward the top with respect to the base.

Since the conventional voice coil motor is driven in only one direction, a driving force greater than the weight of the bobbin and the elastic force of the leaf spring is required to drive the voice coil motor, and thus power consumption of the voice coil motor is greatly increased.

In addition, since a driving force greater than the bobbin's own weight and the elastic force of the leaf spring is required to drive the voice coil motor, the size of the coil wound on the magnet or bobbin increases, thereby increasing the overall size of the voice coil motor.

(Patent Document 1) KR10-2009-0026480 A

The present invention provides a voice coil motor that drives a mover with a smaller current and suppresses or prevents tilt of the mover depending on the posture of the mover.

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 stator including a first driving unit; a mover disposed inside the stator and including a second driving unit for generating a second magnetic field moved from the stator by the first magnetic field generated from the first driving unit; a base for fixing the stator; and a first elastic member coupled to a lower portion of the mover and opposite to the lower portion of the mover to maintain the mover spaced apart from the base when a driving signal is not applied to any one of the first and second driving units and an elastic member including a second elastic member coupled to the upper part, and in order to prevent tilt of the movable member by the center of gravity of the movable member, the first and second elastic members have different spring constants (K). have

In one embodiment, the voice coil motor includes a stator including a first driving unit; a mover disposed inside the stator and including a second driving unit for generating a second magnetic field moved from the stator by the first magnetic field generated from the first driving unit; a base for fixing the stator; and a first elastic member coupled to a lower portion of the mover and opposite to the lower portion of the mover to maintain the mover spaced apart from the base when a driving signal is not applied to any one of the first and second driving units and an elastic member including a second elastic member coupled to the upper part of the movable body, and offsetting a moment of the movable member caused by the center of gravity of the movable member eccentric to one side from the center of the movable member to prevent tilt of the movable member In order to do this, the first and second elastic members have different spring constants (K).

According to the voice coil motor according to the present invention, a bobbin equipped with a lens is floated from a bobbin receiving groove formed on an upper surface of a base on which an image sensor is mounted, and the mover is driven in both directions in a direction away from the base or approaching the base. The motor can be driven with low current and power consumption can be reduced, the focus between the lens and the image sensor can be adjusted within a shorter time, and the contact noise caused by the operation of the bobbin can be reduced, and the center of gravity of the mover spaced from the base This has the effect of improving the image quality by preventing the mover from being tilted.

1 is a cross-sectional view conceptually illustrating a voice coil motor according to an embodiment of the present invention.
FIG. 2 is an exploded perspective view illustrating a specific configuration of the voice coil motor of FIG. 1 .
FIG. 3 is an assembly cross-sectional view of FIG. 2 .
4 and 5 are cross-sectional views comparing the voice coil motor according to the first comparative example and an embodiment of the present invention.
6 and 7 are cross-sectional views illustrating a second comparative example and a voice coil motor according to an embodiment of the present invention.

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 conceptually illustrating a voice coil motor according to an embodiment of the present invention. FIG. 2 is an exploded perspective view illustrating a specific configuration of the voice coil motor of FIG. 1 . FIG. 3 is an assembly cross-sectional view of FIG. 2 .

1 to 3 , the voice coil motor 600 includes a stator 100 , a mover 200 , a base 300 , and an elastic member 400 . In addition, the voice coil motor 600 may include a cover can 500 .

The stator 100 includes a first driving unit 120 and a housing 150 . The stator 100 generates a magnetic field for driving a mover 200 to be described later.

The first driving unit 120 may include, for example, a coil block formed by winding a long wire insulated by an insulating resin in a cylindrical shape. When a voltage having a voltage difference is applied to the first driving unit 120 including a coil block formed by winding a long wire insulated by an insulating resin, a first magnetic field is generated from the first driving unit 120 , The direction of the magnetic field is changed according to the direction of the current flowing through the first driver 120 .

Although it is illustrated and described that the first driving unit 120 of the stator 100 is a coil block in an embodiment of the present invention, the first driving unit 120 may include a magnet for generating a magnetic field.

The housing 150 fixes the first driving unit 120 . The housing 150 includes, for example, a housing body 152 and posts 154 .

The housing body 152 is formed in, for example, a rectangular plate shape, and an opening 153 exposing a lens mounted on a bobbin to be described later is formed in the central portion of the housing body 152 .

A plurality of coupling bosses 156 for fixing an elastic member to be described later are formed on the upper surface of the housing body 152 .

The pillars 154 protrude from the four corners of the lower surface of the housing body 152 facing the base 300 , respectively. The inner surface of the first driving unit 120 including the coil block is fixed to the outer peripheral surface of the pillars (154). The pillars 154 may be coupled to the upper surface of the base 300 to be described later.

In one embodiment of the present invention, the first driving unit 120 including the coil block is attached to the pillars 154 of the housing 150 by an adhesive or the like in a state in which it is wound in a cylindrical shape or the pillars of the housing 150 ( 154) can be directly wound on them.

As shown in FIG. 2 , the housing 150 is a first positioned lower than the upper surface of the housing 150 at a position corresponding to the second connection elastic part 453 of the second elastic member 450 . It may include a surface 157 . The first surface 157 of the housing 150 may be formed by a groove recessed from the upper surface of the housing 150 and opened inwardly.

The mover 200 includes a bobbin 210 and a second driving unit 250 .

A cylindrical lens 205 is fixed inside the bobbin 210 . The mover 200 moves with respect to the stator 100 to adjust the distance between the image sensor and the lens 205 disposed on the lower surface of the base 300 to be described later.

The bobbin 210 is, for example, formed in a hollow cylindrical shape, and a screw thread for fixing the lens 205 is formed on the inner circumferential surface of the bobbin 210 .

Flat fixing parts 215 for fixing the second driving parts 250 are formed on the outer peripheral surface of the bobbin 210 . For example, four fixing parts 215 are formed at equal intervals on the outer peripheral surface of the bobbin 210 , for example.

The second driving units 250 may include, for example, a magnet having a plate shape and generating a second magnetic field, and the second driving units 250 are fixed portions 215 formed on the outer circumferential surface of the bobbin 210 . is fixed on Each of the second driving units 250 may be attached to the fixing unit 215 using an adhesive or the like.

Each of the second driving units 250 is disposed to face the first driving unit 120 of the stator 100 .

Although it is illustrated and described that the second driving unit 250 is a magnet in an embodiment of the present invention, the second driving unit 250 may include a coil block formed by winding an insulated long electric wire.

For example, when the first driving unit 120 includes a coil block, the second driving unit 250 includes a magnet, and conversely, when the first driving unit 120 includes a magnet, the second driving unit 250 includes a coil block.

The mover 200 by the attractive or repulsive force generated by the first magnetic field generated from the first driving unit 120 of the stator 100 and the second magnetic field generated from the second driving unit 250 of the mover 200 . is up-down based on the base 300 to be described later. Meanwhile, in one embodiment of the present invention, the mover 200 is spaced apart from the upper surface of the base 300 in a state in which a driving signal is not applied to the first driving unit 120 or the second driving unit 250 .

The base 300 is, for example, formed in the shape of a rectangular parallelepiped plate, and serves to fix the stator 100 .

An opening 310 through which the light passing through the lens 205 built in the bobbin 210 of the mover 200 passes is formed in the central portion of the base 300 .

At the four corners of the upper surface 320 of the base 300 formed in a plate shape, coupling posts 325 are formed, respectively, and the coupling posts 325 mutually couple the cover can 500 and the base 300 to be described later. plays a role

An IR filter 301 and an image sensor (not shown) that generate an image corresponding to the light passing through the lens 205 of the bobbin 210 are fixed to the rear surface of the base 300 .

Meanwhile, a bobbin receiving groove 330 concavely formed from the upper surface 320 is formed on the upper surface 320 of the base 300 . The bobbin receiving groove 330 serves to receive the lower end of the bobbin 210 .

The bobbin receiving groove 330 is formed to be larger than the planar area of the bobbin 210 , and the bobbin 210 and the base 300 may partially overlap each other by the bobbin receiving groove 330 .

In one embodiment of the present invention, the depth of the bobbin receiving groove 330 may be formed in consideration of the stroke length of the mover 200 .

Meanwhile, the shock absorbing member 350 formed along the opening 310 of the base 300 is disposed on the bottom surface 335 of the base 300 formed by the bobbin receiving groove 330 . The shock absorbing member 350 absorbs, for example, shock and vibration caused by the collision between the bobbin 210 and the bottom surface 335 of the base 300 .

In an embodiment of the present invention, the shock absorbing member 350 may include any one of a sponge, a synthetic resin having elasticity, and rubber, and the shock absorbing member 350 may be formed in an annular plate shape having a thin thickness. can

In an embodiment of the present invention, in a state in which a driving signal is not applied to the first driving unit 120 of the stator 100 and the second driving unit 250 of the mover 200 , the mover 200 includes an elastic member ( 400) from the upper surface of the base 300.

As such, when the mover 200 is spaced apart from the upper surface of the base 300 in a state in which the driving signal is not applied, the second driving unit 250 of the mover 200 or the first driving unit of the stator 100 ( As a driving signal is applied to any one of 120 , the mover 200 moves in a direction away from the upper surface of the base 300 or in a direction closer to the upper surface of the base 300 . Accordingly, the intensity of current and power consumption required to drive the mover 200 can be greatly reduced.

The elastic member 400 for separating the movable member 200 from the upper surface of the base 300 includes a first elastic member 440 and a second elastic member 450 .

The elastic member 400 has a bottom surface formed by the bobbin receiving groove 330 formed on the lower surface of the bobbin 210 and the upper surface 320 of the base 300 when a driving signal is not applied to the second driving unit 250 . (335) to be spaced apart.

The first elastic member 440 elastically supports the lower portion of the bobbin 210 of the mover 200 , and the first elastic member 440 has a lower surface of the bobbin 210 of the mover 200 as the base 300 . ) to float on the upper portion of the bobbin receiving groove 330 .

The first elastic member 440 includes a first inner elastic part 410 , a first outer elastic part 420 , and a first connection elastic part 430 .

The first inner elastic part 410 is formed in, for example, an annular ring shape, and the first inner elastic part 410 is coupled to a lower surface or a lower end of the bobbin 210 . The first inner elastic part 410 is coupled to the lower surface of the bobbin 210 by, for example, an adhesive or thermal fusion.

Since the first inner elastic part 410 is coupled to the lower surface or the lower end of the bobbin 210 , the first inner elastic part 410 is also formed in a size to be inserted into the bobbin receiving groove 330 of the base 300 .

The first outer elastic part 420 is disposed outside the first inner elastic part 410 , and the first outer elastic part 420 is formed in a rectangular frame shape.

The first outer elastic part 420 is formed in a size larger than the bobbin receiving groove 330 of the base 300 , and thus the first outer elastic part 420 is disposed on the upper surface 320 of the base 300 . The first outer elastic part 420 may be fixed on the upper surface 320 of the base 300 by, for example, pillars 154 of the housing 150 of the stator 100 .

The first connection elastic part 430 elastically connects the first inner elastic part 410 and the first outer elastic part 420 to each other, and the first inner elastic part 410 by the first connection elastic part 430 . ) is elastic. The first connection elastic part 430 has a first spring constant (K), and the first spring constant (K) may be changed by the shape, thickness, length, and dimensions of the first connection elastic part 430 .

Although it is shown and described that the first elastic member 440 is formed as one in one embodiment of the present invention, differently, the first elastic member 440 has a mutually symmetrical shape and a pair of lower surfaces of the bobbin 210 It is free even if it is connected to

The second elastic member 450 is coupled to the coupling boss 156 formed on the upper surface of the housing body 152 of the housing 150 of the stator 100 .

The second elastic member 450 includes a second inner elastic part 451 , a second outer elastic part 452 , and a second connection elastic part 453 .

The second inner elastic part 451 is coupled to an upper surface or an upper end of the bobbin 210 , and the second outer elastic part 452 is disposed on the upper surface of the housing body 152 . The second connecting elastic portion 453 interconnects the second outer and second inner elastic portions 451 and 452, and the second connecting elastic portion 453 has a second spring constant (K). The second spring constant (K) of the second elastic connection part 453 may be changed according to the shape, thickness, length and dimension of the second elastic part 453 .

A coupling hole 455 coupled to the coupling boss 156 formed on the top surface of the housing body 152 is formed in the second outer elastic part 452 disposed on the upper surface of the housing body 152 .

Referring back to FIG. 2 , the voice coil motor 600 may further include a cover can 500 .

The cover can 500 includes an upper plate 510 having an opening exposing the lens 205 of the mover 200 and a side plate 520 extending from the edge of the upper plate 510 toward the base 300 . Including, the side plate 520 is coupled to the side of the base (300).

Referring back to FIG. 1 , the bobbin 210 of the mover 200 according to an embodiment of the present invention is the base 300 by the force generated from the first driving unit 120 and the second driving unit 250 . Driven in the first direction FD away from the upper surface 320 of the base 300 and the second direction SD facing the bottom surface of the bobbin receiving groove 330 of the base 300 in the opposite direction to the first direction FD, respectively can be

In one embodiment of the present invention, the bobbin 210 of the mover 200 is driven in the first direction FD, for example, when a forward current is applied to the first driving unit 120 , and the bobbin 210 ) is driven in the second direction SD that is opposite to the first direction when a reverse current that is opposite to the forward current is applied to the first driver 120 .

In this case, the forward current or the reverse current applied to the first driving unit 120 may be implemented by adjusting the voltage difference applied to both ends of the first driving unit 120 .

In the voice coil motor 600 shown in FIGS. 1 to 3, when the optical axis of the lens 205 is vertically disposed with respect to the ground (or horizontal plane), that is, the voice coil motor 600 is positioned on the ground (or horizontal plane). In a properly placed state, the mover 200 of the voice coil motor 600 is disposed without tilting in a direction perpendicular to the ground.

However, when a user images an object using a smart phone equipped with the voice coil motor 600 , the voice coil motor 600 is disposed in various directions. For example, when the optical axis of the lens 205 mounted on the mover 200 of the voice coil motor 600 is directed in a direction parallel to the ground (or horizontal plane), it is moved according to the center of gravity of the mover 200 . A moment is applied to the ruler 200 according to gravity and the position of the center of gravity of the mover 200 , and thus the mover 200 may be tilted.

In one embodiment of the present invention, the voice coil motor 600 suppresses or prevents the tilt of the mover 200 that is generated as the posture or arrangement is changed with respect to the reference plane (ground or horizontal plane).

The first elastic member 440 of the elastic member 400 elastically supporting the movable member 200 in order to suppress or prevent the tilt of the movable member 200 according to a change in the posture or arrangement of the voice coil motor 600 . ) and the second elastic member 450 have different spring constants (K) corresponding to the center of gravity of the mover 200 .

Although it has been shown and described that the first and second elastic members 440 and 450 have different spring constants (K) corresponding to the center of gravity of the mover 200 in one embodiment of the present invention, the mover 200 ) It is also possible for the first and second elastic members 440 and 450 to have different elastic moduli E with respect to the center of gravity.

4 is a cross-sectional view illustrating a voice coil motor according to a comparative example as compared to a voice coil motor according to an embodiment of the present invention.

4, the mover 200a is coupled to the stator 100a by elastic members 440a, 450a; 400a, and the mover 200a is the base 300a when no driving signal is applied. separated from the upper surface. In the comparative example, the first elastic member 440a and the second elastic member 450a of the elastic member 400a have the same elastic modulus E and the same spring constant K, respectively. In addition, in the comparative example, the center of gravity G of the mover 200a is formed at a position spaced apart toward the top of the mover 200a by the length of L1 based on the center C of the mover 200a. .

In the comparative example, when the optical axis of the mover 200a of the voice coil motor 600a is disposed parallel to the ground, that is, toward the second direction SD, which is a direction in which the elastic member 400a is perpendicular to the ground. When disposed, a moment (M) is generated by the weight of the movable member (200a) at the center of gravity (G) of the movable member (200a), and the movable member (200a) is a moment (M) generated in a clockwise direction. is tilted by

In the comparative example, as the mover 200a is tilted, the optical axis of the lens may not coincide with the optical axis of the image sensor, which may cause serious image generation failure.

5 is a cross-sectional view illustrating a voice coil motor according to an embodiment of the present invention in contrast to the comparative example shown in FIG. 4 .

Referring to FIG. 5 , the mover 200 is coupled to the stator 100 by elastic members 440 , 450 ; 400 , and the mover 200 is moved from the upper surface of the base 300 when no driving signal is applied. are spaced apart The first elastic member 440 and the second elastic member 450 of the elastic member 400 have different spring constants (K). In addition, the center of gravity G of the mover 200 is spaced apart toward the top of the mover 200 by the length of L1 based on the center C of the mover 200 in the same way as in the comparative example of FIG. 4 . formed in position.

When the optical axis of the mover 200 of the voice coil motor 600 is disposed parallel to the ground, that is, when the elastic member 400 is disposed toward the second direction SD, which is a direction perpendicular to the ground, In the center of gravity G of the mover 200, a moment M due to the weight of the mover 200 is generated, but in an embodiment of the present invention, as in the comparative example of FIG. 200) does not occur.

This is because the first and second elastic members 440 and 450 have different spring constants (K) as described above in order to prevent the mover 200 from tilting by the center of gravity G of the mover 200 . to be.

Specifically, when the center of gravity G of the mover 200 is formed close to the second elastic member 450 with respect to the center C of the mover 200, the first elastic member 440 is While having 1 spring constant (K1), the second elastic member 450 is greater than the first spring constant (K1) of the first elastic member 440 in order to cancel the moment to prevent the mover 200 from tilting. It has a second spring constant (K2).

In an embodiment of the present invention, the second spring constant (K2) has a value suitable for canceling the moment tilting the mover 200, and the second spring constant (K2) is the center ( C) and the center of gravity (G) of the mover 200 may be increased in proportion to the length (L1). Alternatively, the first spring constant K1 of the first elastic member 440 may be decreased in inverse proportion to the second spring constant K2.

In one embodiment of the present invention, the first elastic member 440 has a first spring constant (K1), the second elastic member 450 is a second spring constant (K2) greater than the first spring constant (K1) To have a , the first elastic member 440 may have a first cross-sectional area, and the second elastic member 450 may have a second cross-sectional area larger than the first cross-sectional area.

In addition, in order for the first elastic member 440 to have a first spring constant (K1) and the second elastic member 450 to have a second spring constant (K2) greater than the first spring constant (K1), the second The first connecting elastic portion 430 of the first elastic member 440 has a first length, and the second connecting elastic portion 453 of the second elastic member 450 has a second length longer than the first length. is formed

In addition, in order for the first elastic member 440 to have a first spring constant (K1) and the second elastic member 450 to have a second spring constant (K2) greater than the first spring constant (K1), the second The first connection elastic part 430 of the first elastic member 440 and the second connection elastic part 453 of the second elastic member 450 may be formed in different shapes.

6 is a cross-sectional view illustrating a voice coil motor according to Comparative Example 2 as compared with the voice coil motor according to an embodiment of the present invention.

Referring to FIG. 6 , the mover 200b is coupled to the stator 100b by elastic members 440b, 450b; 400b, and the mover 200b moves to the base 300b when a driving signal is not applied. separated from the upper surface. In Comparative Example 2, the first elastic member 440b and the second elastic member 450b of the elastic member 400b have the same elastic modulus E and the same spring constant K, respectively. Further, in Comparative Example 2, the center of gravity G of the mover 200b is formed at a position spaced apart from the center C of the mover 200b toward the lower end of the mover 200b by the length of L1. do.

In Comparative Example 2, when the optical axis of the mover 200b of the voice coil motor 600b is disposed parallel to the ground, that is, the second direction SD of the elastic member 400b is perpendicular to the ground. When placed toward the center of gravity G of the mover 200b, a moment M due to the weight of the mover 200b is generated, and the mover 200b has a counterclockwise moment ( It is tilted by M).

In Comparative Example 2, as the mover 200b is tilted counterclockwise, the optical axis of the lens does not coincide with the optical axis of the image sensor, which may cause serious image generation failure.

7 is a cross-sectional view illustrating a voice coil motor according to an embodiment of the present invention in contrast to Comparative Example 2 shown in FIG. 6 .

Referring to FIG. 7 , the mover 200 is coupled to the stator 100 by elastic members 440 , 450 ; 400 , and the mover 200 moves from the upper surface of the base 300 when no driving signal is applied. are spaced apart The first elastic member 440 and the second elastic member 450 of the elastic member 400 have different spring constants (K). In addition, the center of gravity G of the mover 200 is spaced apart toward the lower end of the mover 200 by the length of L1 based on the center C of the mover 200 in the same manner as in Comparative Example 2 of FIG. 6 . formed in a location

When the optical axis of the mover 200 of the voice coil motor 600 is disposed parallel to the ground, that is, when the elastic member 400 is disposed toward the second direction SD, which is a direction perpendicular to the ground, In the center of gravity G of the mover 200, a moment M due to the weight of the mover 200 is generated, but in an embodiment of the present invention, as in the comparative example of FIG. 200) does not occur.

This is because the first and second elastic members 440 and 450 have different spring constants (K) as described above in order to prevent the mover 200 from tilting by the center of gravity G of the mover 200 . to be.

Specifically, when the center of gravity (G) of the mover 200 is formed close to the first elastic member 440 with respect to the center (C) of the mover 200 , the second elastic member 450 is the second elastic member 450 . 2 has a spring constant (K2), while the first elastic member 440 is greater than the second spring constant (K2) of the second elastic member 450 in order to offset the moment to prevent the mover 200 from tilting. It has a first spring constant (K1).

In one embodiment of the present invention, the first spring constant (K1) of the first elastic member 440 has a value suitable for offsetting the moment (M) for tilting the mover 200, the first spring constant ( K1) may increase in proportion to the length L1 between the center (C) of the mover 200 and the center of gravity (G) of the mover 200 . Alternatively, the second spring constant K2 of the second elastic member 450 may be reduced in inverse proportion to the first spring constant K1.

In one embodiment of the present invention, the second elastic member 450 has a second spring constant (K2), the first elastic member 440 is a first spring constant (K1) greater than the second spring constant (K2) In order to have a , the first elastic member 440 may have a first cross-sectional area, and the second elastic member 450 may have a second cross-sectional area smaller than the first cross-sectional area.

In addition, in order for the first elastic member 440 to have a first spring constant (K1) and the second elastic member 450 to have a second spring constant (K2) greater than the first spring constant (K1), the second The first connecting elastic portion 430 of the first elastic member 440 has a first length, and the second connecting elastic portion 453 of the second elastic member 450 has a second length shorter than the first length. is formed

In addition, the second elastic member 450 has a second spring constant (K2), in order to have the first elastic member 450 have a first spring constant (K1) greater than the second spring constant (K2), The first connection elastic part 430 of the first elastic member 440 and the second connection elastic part 453 of the second elastic member 450 may be formed in different shapes.

As described above, a technique for individually adjusting the spring constant (K) of the first elastic member 440 and the second elastic member 450 coupled to the upper and lower ends of the movable member to prevent tilt of the movable member is disclosed. However, alternatively, the tilt of the mover may be prevented by changing the intrinsic modulus of elasticity E of the first and second elastic members 440 and 450 .

As described in detail above, the voice coil motor is operated by floating the bobbin with the lens from the bobbin receiving groove formed on the upper surface of the base on which the image sensor is mounted and driving the mover in both directions away from the base or approaching the base. It can reduce driving and power consumption with low current, adjust focus between lens and image sensor within a shorter time, reduce contact noise caused by bobbin driving, and operate by the center of gravity of the mover separated from the base It has the effect of improving image quality by preventing self-tilting.

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...stator
200...Movers 300...Base
400...Elastic member 500...Cover can

Claims (20)

cover;
a bobbin disposed within the cover;
a housing disposed between the bobbin and the cover;
a base disposed under the bobbin and coupled to the cover;
a magnet and a coil disposed in the cover and configured to move the bobbin in an optical axis direction;
a first elastic member connecting the bobbin and the base; and
and a second elastic member connecting the bobbin and the housing,
The first elastic member includes a first outer portion coupled to the base, a first inner portion coupled to the bobbin, and a first connection elastic portion connecting the first outer portion and the first inner portion,
The second elastic member includes a second outer portion coupled to the upper surface of the housing, a second inner portion coupled to the bobbin, and a second connecting elastic portion connecting the second outer portion and the second inner portion,
and the housing includes a first surface disposed at a position corresponding to the second connection elastic part of the second elastic member and lower than a position of the upper surface of the housing. According to claim 1,
The upper surface of the housing and the first surface of the housing form a step difference. The method of claim 1,
The first surface of the housing is formed by a groove recessed from the upper surface of the housing and opened inwardly. According to claim 1,
The cover includes a top plate, and a side plate extending from the top plate and coupled to the base,
The housing includes a coupling boss protruding from the upper surface of the housing,
The upper surface of the housing is spaced apart from the upper plate of the cover by the coupling boss. According to claim 1,
The spring constant of the first connection elastic part is different from the spring constant of the second connection elastic part. The method of claim 1,
The shape of the first connection elastic part is different from the shape of the second connection elastic part. According to claim 1,
The length of the first connection elastic part is different from the length of the second connection elastic part. The method of claim 1,
and a portion having a cross-sectional area different from a cross-sectional area of the second connecting elastic part of the first connecting elastic part. According to claim 1,
A length of the second connecting elastic part is longer than a length of the first connecting elastic part. According to claim 1,
A length of the first connecting elastic part is longer than a length of the second connecting elastic part. According to claim 1,
The position of the first inner portion of the first elastic member by the movement of the bobbin is a voice coil motor disposed below the position of the first outer portion along the optical axis direction based on the first outer portion of the first elastic member . According to claim 1,
The position of the second inner portion of the second elastic member is lower than the position of the second outer portion in the optical axis direction based on the second outer portion of the second elastic member by the movement of the bobbin. . According to claim 1,
When a forward current is applied to the coil, the first of the first elastic member so that the position of the first inner portion of the first elastic member is located at a higher position than the position of the first outer portion of the first elastic member The connecting elastic portion is deformed,
When a reverse current is applied to the coil, the first inner portion of the first elastic member is positioned at a lower position than that of the first outer portion of the first elastic member. The connecting elastic part is a deformable voice coil motor. 5. The method of claim 4,
The second connecting elastic part of the second elastic member is spaced apart from the upper plate of the cover upwardly and spaced apart from the housing downwardly. According to claim 1,
and a mover including the bobbin and the coil;
A voice coil motor in which the center of gravity of the mover is disposed closer to the first elastic member than to the second elastic member. housing;
a bobbin disposed within the housing;
a base disposed under the bobbin;
a cover including an upper plate and a side plate extending from the upper plate and coupled to the base;
a magnet and a coil for moving the bobbin in an optical axis direction;
a first elastic member connecting the bobbin and the base; and
and a second elastic member connecting the bobbin and the housing,
The first elastic member includes a first outer portion coupled to the base, a first inner portion coupled to the bobbin, and a first connection elastic portion connecting the first outer portion and the first inner portion,
The second elastic member includes a second outer portion coupled to the upper surface of the housing, a second inner portion coupled to the bobbin, and a second connecting elastic portion connecting the second outer portion and the second inner portion,
The housing includes a groove recessed from the upper surface of the housing,
The groove of the housing includes a first surface disposed at a position corresponding to the second connection elastic portion of the second elastic member in the optical axis direction,
The housing includes a coupling boss protruding from the upper surface of the housing,
The upper surface of the housing is spaced apart from the upper plate of the cover by the coupling boss. 17. The method of claim 16,
The upper surface of the housing and the first surface of the housing form a step difference. 17. The method of claim 16,
When a forward current is applied to the coil, the first of the first elastic member so that the position of the first inner portion of the first elastic member is located at a higher position than the position of the first outer portion of the first elastic member The connecting elastic portion is deformed,
When a reverse current is applied to the coil, the first inner portion of the first elastic member is positioned at a lower position than that of the first outer portion of the first elastic member. The connecting elastic part is a deformable voice coil motor. image sensor;
The voice coil motor of any one of claims 1 to 18; and
and a lens coupled to the bobbin of the voice coil motor and spaced apart from the image sensor. A mobile phone comprising the camera of claim 19 .

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