KR20220153529A - Lens moving unit and camera module having the same - Google Patents

Abstract

The present invention provides a lens driving device, capable of receiving feedback about position information on a bobbin, and a camera module including the same. According to an embodiment of the present invention, the lens driving device includes: the bobbin having at least one or more sheets of lens, wherein a coil unit is arranged on the outer circumference of the bobbin; a housing member having a magnet installed at a position corresponding to the coil unit; upper and lower elastic members elastically supporting a movement of a parallel direction to an optic axis of the lens in the bobbin as one end is connected to the upper surface and the lower surface surfaces, respectively, of the bobbin; and a sensing unit sensing the movement of the parallel direction to the optic axis of the bobbin. The sensing unit includes: a sensing magnet installed on the outer circumference of the bobbin; and a circuit board installed on a side wall of the housing member, and having a position sensor arranged on the inner surface facing the sensing magnet.

Description

Lens driving unit and camera module having the same {Lens moving unit and camera module having the same}

This embodiment relates to a lens driving device and a camera module having the same.

The camera module includes a printed circuit board on which an image sensor and an image sensor that transmits electrical signals are mounted, an infrared cut-off filter that blocks infrared light from the image sensor, and at least one lens that transmits an image to the image sensor. It may include an optical system consisting of. At this time, a lens driving device capable of performing an auto focusing function and a hand shake correction function may be installed in the optical system.

The lens driving device can be configured in various ways, and a voice coil unit motor is generally used. The voice coil unit motor may perform an auto-focusing function by operating by electromagnetic interaction between a magnet fixed to the housing and a coil unit wound on an outer circumferential surface of a bobbin coupled with a lens barrel. In such a voice coil motor type actuator module, a bobbin that moves up and down can be reciprocally moved in a direction parallel to an optical axis while being elastically supported by lower and upper elastic members.

Recently, in order to shorten the auto-focusing time of the camera module, there is a need for the development of a lens driving device that quickly grasps the optimal focusing position by receiving feedback on the location information of the bobbin where the lens is installed. The performance of the lens driving device, such as the eccentricity of the barrel, may deteriorate.

(Patent Document 1) KR 10-2012-0025811 A

The present embodiment provides a lens driving device capable of receiving feedback on bobbin position information and a camera module having the same.

A lens driving device according to the present embodiment includes a bobbin in which at least one lens is installed and a coil unit is disposed on an outer circumferential surface; a housing member in which a magnet is installed at a position corresponding to the coil unit; upper and lower elastic members having one ends coupled to upper and lower surfaces of the bobbin to elastically support movement of the bobbin in a direction parallel to the lens optical axis direction; and a sensing unit that detects movement in a direction parallel to the optical axis of the bobbin, wherein the sensing unit includes a sensing magnet installed on an outer circumferential surface of the bobbin; and a circuit board installed on a sidewall of the housing member and having a position sensor disposed on an inner surface facing the sensing magnet.

The lens driving device according to the present embodiment may further include a cover member surrounding the housing member, and the cover member may include a window on a surface corresponding to the sensing magnet.

The cover member may be formed of a metallic material.

In the bobbin, a magnet mounting portion to which the sensing magnet is mounted may protrude from an outer circumferential surface of the bobbin.

The magnet mounting part may be disposed at a position that does not interfere with the coil unit.

The magnet mounting part may be disposed above the coil unit.

The magnets may be disposed parallel to each other on two surfaces of the housing member facing each other.

The sensing magnet and the magnet may be disposed on different surfaces so as not to face each other.

The position detection sensor is a hall sensor, and a plurality of terminals may be installed on the circuit board to be exposed to the outside.

The camera module according to the present embodiment includes an image sensor; a printed circuit board on which the image sensor is mounted; and a lens driving device configured as described above.

By installing a sensing magnet on the outer surface of the bobbin, the position of the sensing magnet can be detected by a position sensor such as a hall sensor, so that the position of the bobbin during auto focusing operation can be accurately identified.

In addition, since the sensing magnet is installed on the outer surface of the bobbin, the assembly process is simple.

In addition, since the movement of the bobbin in the optical axis direction is controlled by arranging an even number of magnets to face each other, the electromagnetic force acting on the coil unit can be well balanced.

In addition, by forming a window in the cover member corresponding to the sensing magnet, it is possible to prevent the deterioration of the preceding movement characteristic of the bobbin due to the attractive force between the sensing magnet and the cover member.

1 is a schematic perspective view of a camera module according to this embodiment;
Figure 2 is an exploded perspective view of Figure 1;
3 is an enlarged perspective view of the bobbin of FIG. 2;
Figure 4 is a front view of Figure 1;
5 is a section II of FIG. 4, and
6 is a front view of the lens driving device from which the circuit board is removed according to the present embodiment.

Hereinafter, embodiments of the present embodiment will be described with reference to the accompanying drawings.

1 is a schematic perspective view of a camera module according to this embodiment, FIG. 2 is an exploded perspective view of FIG. 1, FIG. 3 is an enlarged perspective view of the bobbin of FIG. 2, FIG. 4 is a front view of FIG. 1, and FIG. The II-I cross-sectional view of FIG. 4 and FIG. 6 is a front view of the lens driving device from which the circuit board is removed according to the present embodiment.

As shown in FIGS. 1 and 2 , the lens driving device according to the present embodiment may include a base 20 , a bobbin 30 , and a cover member 60 . The cover member 60 may form the outer periphery of the camera module, and as shown, a housing member 40 supporting a magnet 41 to be described later may be further disposed inside the cover member 60. . Hereinafter, the cover member 60 may be referred to as a 'cover'.

The base 20 may be combined with the cover member 60 .

The bobbin 30 may be installed in the inner space of the cover member 60 to be reciprocally movable in a direction parallel to the optical axis. A coil unit 31 may be installed on an outer circumferential surface of the bobbin 30 .

The bobbin 30 may include a lens barrel 32 in which at least one lens 32a is installed. As shown in FIG. 2, the lens barrel 32 is the inside of the bobbin 30. It may be formed to be screwable to. However, this is not limited, and although not shown, the lens barrel 32 is directly fixed to the inside of the bobbin 30 by a method other than screwing, or the one or more lenses 32a without the lens barrel 32 It is also possible to be integrally formed with the bobbin. The lens 32a may be composed of one sheet, or two or more lenses may form an optical system.

The bobbin 30 may have upper and lower elastic members 51 and 52 respectively installed at upper and lower portions. One end of the upper elastic member 51 is connected to the bobbin 30 and the other end may be coupled to the cover member 60 or the housing member 40, and when coupled to the housing member 40, the upper portion of the housing member It can be bonded to the face or bottom face. One end of the lower elastic member 52 may be connected to the bobbin 30 and the other end may be coupled to the upper surface of the base 20 . In addition, a protrusion for coupling the lower elastic member 52 may be formed on the lower side of the base 20, and a hole or recess is formed at a corresponding position of the lower elastic member 52 to By coupling, the lower elastic member 52 can be fixed and rotation can be prevented. In addition, an adhesive or the like may be added for firm fixation.

On the other hand, the upper elastic member 51 is composed of one body as shown in FIG. 2, and the lower elastic member 52 is provided with two springs in a two-part structure, and can receive power of different polarities. That is, power applied through a terminal not shown is transmitted to two springs of the lower elastic member 52, and this power may be applied to the coil unit 31 wound around the bobbin 30. To this end, the lower elastic member 52 and the coil unit 31 may be energized by soldering or the like. That is, both ends of the two springs and the coil unit 31 may be electrically connected by soldering or the like. However, it is not limited thereto, and on the contrary, it is also possible that the upper elastic member 51 is formed in a bipartite structure and the lower elastic member 52 is integrally configured.

The bobbin 30 may be moved in both directions in the optical axis direction by the upper and lower elastic members 51 and 52 . That is, since the bobbin 30 is spaced apart from the base 20 by a predetermined distance, the bobbin 30 can be controlled to move upward and downward around the initial position of the bobbin 30 . In addition, since the initial position of the bobbin 30 becomes the upper surface of the base 20, movement of the bobbin 30 only upward can be controlled with the initial position of the bobbin 30 as the center.

Meanwhile, the coil unit 31 may be provided as a ring-shaped coil block coupled to the outer circumferential surface of the bobbin 30 . However, this is not limited, and the coil may be directly wound on the outer circumferential surface of the bobbin 30. As shown in FIG. 3, the coil unit 31 may be installed at a position close to the lower surface of the bobbin 30, and may include a straight surface and a curved surface depending on the shape of the bobbin 30. .

Alternatively, the coil unit 31 formed of coil blocks may have an angular shape or an octagonal shape. That is, all of them may be formed as straight surfaces without curved surfaces. This is in consideration of the electromagnetic action with the magnets 41 disposed opposite to each other. If the corresponding surface of the magnet 41 is flat, the electromagnetic force can be maximized when the face of the facing coil unit 31 is flat. However, it is not limited thereto, and the surface of the magnet 41 and the surface of the coil unit 31 may all be curved, both flat, or one curved and the other flat, depending on design specifications.

In addition, the bobbin 30 has a first surface formed flat on a surface corresponding to the straight surface and a second surface formed round on a surface corresponding to the curved surface so that the coil unit 31 can be coupled to the outer circumferential surface. It may include a surface, but the second surface may also be a flat surface. At this time, a groove 33 corresponding to an inner yoke 61 to be described later may be formed on the upper side of the second surface, and the coil unit 31 may be disposed below the groove 33, but the coil unit 31 ) A portion of the groove 33 may be disposed even. However, it is not limited thereto, and a separate yoke may be provided and installed instead of the inner yoke 61 .

The housing member 40 may be composed of a substantially hexahedral frame. A coupling structure for coupling the upper and lower elastic members 51 and 52 may be provided on the upper and lower surfaces of the housing member 40, and a magnet 41 may be installed on each surface. At this time, as shown in FIG. 2, a mounting hole 42a in which the magnet 41 is installed may be formed, but is not limited thereto, and the magnet 41 is directly placed on the inner circumferential surface of the housing member 40 without the mounting hole 42a. It can also be adhesively fixed. In this way, when the magnet 41 is directly fixed to the housing member 40 , the magnet 41 may be directly bonded and fixed to the side surface or corner of the housing member 40 .

In addition, the housing member 40 may be additionally provided with a through hole 42b in addition to the mounting hole 42a. A pair of through holes 42b may be formed to face each other as shown, but this is not limited thereto. . That is, a through hole 42b larger than the size of the sensing magnet 100 may be formed on a wall surface of the housing member 40 facing the sensing magnet 100, which will be described later. At this time, the through hole 42b may be rectangular, or may be provided in a circular or polygonal shape. Alternatively, the existing housing member 40 having four mounting holes 42a may be used as it is, the magnets 41 may be installed in the two mounting holes 42a, and the remaining two may be through holes 42b. .

Also, unlike the embodiment, there may be only the cover member 60 without a separate housing member 40 . The cover member 60 may be formed of a ferromagnetic metal material such as iron. In addition, the cover member 60 may be provided in an angular shape when viewed from above so as to cover all of the bobbin 30 . At this time, the cover member 60 may have a quadrangular shape as shown in FIG. 1 or, although not shown, may be provided in an octagonal shape. In addition, if the cover member 60 has an octagonal shape when viewed from above, and the shape of the magnet 41 disposed at the corner of the housing member 40 is trapezoidal when viewed from above, the magnetic field emitted from the corner of the housing member can be minimized.

In the cover member 60, the inner yoke 61 may be integrally formed at a position corresponding to the receiving groove. According to the present embodiment, one side of the inner yoke 61 is the coil unit 31 It is spaced a certain distance from, and the other side surface may be arranged to be spaced apart from the bobbin 30 by a certain distance. Also, the inner yoke 61 may be formed at four corners of the housing member 40 . The inner yoke 61 may be bent from the upper surface of the housing member 40 inward in a direction parallel to the optical axis. Although not shown in the inner yoke 61, an escape groove may be formed at a position close to the bent portion. These escape grooves may be formed in pairs or symmetrically, and the bent portion in which the escape grooves are formed forms a bottleneck section. Due to this escape groove formation section, the inner yoke 61 and the bobbin 30 ) can be minimized. That is, when the bobbin 30 moves upward, it is possible to prevent partial damage of the bobbin 30 due to interference of the corner portion of the inner yoke. The end of the inner yoke 61 needs to be spaced apart from the bottom surface of the groove 33 at a reference position by a predetermined distance. This is to prevent contact and interference between the end of the groove and the bottom surface of the groove 33. In addition, the end of the inner yoke 61 may function as a stopper to regulate the movement of the bobbin 30 to a section other than the design specification. In addition, when there is no separate housing member 40, the magnet 41 may be bonded and fixed directly to the side surface or corner of the cover member 60. That is, the magnet 41 may be fixed to the sidewall of the cover member 60 by an adhesive. In addition, the magnetization direction of the magnet 41 may be a side facing the bobbin 30 and a side facing the cover member 60 . However, it is not limited thereto, and the magnetization direction may be changed according to design.

On the other hand, the lens driving device according to the present embodiment may be provided with a sensing unit for sensing the motion of the bobbin 30 .

The sensing unit may include a sensing magnet 100 and a position sensor 210 . Here, the position sensor 210 may be installed on the circuit board 200 . Hereinafter, the position sensor 210 may be referred to as a 'position sensor'.

The sensing magnet 100 may be smaller and thinner than the magnet 41 and may be provided in a square shape as shown. However, it is not limited thereto, and various configurations such as a rectangle, a triangle, a polygon, and a circle are possible.

The sensing magnet 100 may be installed on the outer circumferential surface of the bobbin 30 . According to the present embodiment, the sensing magnet 100 may be fixed to the magnet mount 110 provided on the bobbin 30 with an adhesive or the like. At this time, the magnet mounting portion 110 may include a rib-shaped guide protruding from the outer circumferential surface of the bobbin 30, but is not limited thereto, and a groove portion in which the sensing magnet 100 may be disposed may be formed. have. As shown in FIG. 3 , the rib-shaped guide may have an opening on the lower side and may be provided to cover at least three surfaces of the sensing magnet 100 . At this time, the protruding height of the guide of the magnet mount 110 may correspond to the thickness of the sensing magnet 100 or may be formed to be lower or higher. Therefore, when the sensing magnet 100 is fixed to the magnet mount 110 with an adhesive or the like, the sensing magnet 100 may or may not protrude outside the guide.

Meanwhile, the sensing magnet 100 may be disposed at a position where it does not interfere with the coil unit 31 . That is, when the coil unit 31 is installed on the lower side of the bobbin 30 as shown in FIG. 3 , the sensing magnet 100 may be disposed on the upper side of the coil unit 31 . This is to prevent the coil unit 31 from affecting the lifting operation of the bobbin 30 in the optical axis direction.

Also, as shown in FIG. 2 , the sensing magnet 100 may be disposed so as not to face the magnet 41 . That is, two magnets 41 are provided as a pair, and are arranged to face each other while being parallel. At this time, when the housing member 40 is provided in a rectangular shape, the sensing magnet 100 is not installed at a position facing the two surfaces on which the magnets 41 are installed. The reason for arranging the sensing magnet 100 so as not to face the magnet 41 is to prevent a change in the magnetic force of the sensing magnet 100 from interfering with the magnetic force of the magnet 41, so that the position sensor 210 This is to ensure that the movement of the bobbin 30 can be accurately fed back.

As shown in FIG. 2 , the circuit board 200 may be disposed to correspond to sidewalls of the bobbin 30 , the housing member 40 and/or the cover member 60 . In the present embodiment, a cover member 60 serving as a shield can may be provided, and the circuit board 200 may be closely attached to the sidewall of the cover member 60 . In addition, the circuit board 200 may be contact-fixed to the outer or inner surface of the cover member 60 and may be larger than the window 300 of the cover member 60 . In addition, the circuit board 200 includes a terminal 201 at one end so that it can be electrically connected to the printed circuit board 10 on which the image sensor 11, which will be described later, is mounted. In addition, in order to apply current to the coil unit 31 through the circuit board 200, the coil unit 31 is directly electrically connected to the circuit board 200, or the coil unit 31 is divided into two After being connected to the lower spring, the two lower springs may be electrically connected to the circuit board 200 and electrically connected to the printed circuit board 100 . As a method of electrical connection, various methods such as soldering, conductive epoxy, and Ag epoxy are possible. That is, the two lower springs may be directly soldered to the circuit board 200 .

At this time, since the position sensor 210 such as a Hall sensor is disposed on the inner surface of the circuit board 200, the position sensor 210 is not exposed to the outside. In addition, a window 300 is provided on the sidewall of the cover member 60 corresponding to the position sensor 210, and a through hole 42b is formed in the housing member 40, so that the position sensor 210 may pass through the window 300 and be spaced apart from the sensing magnet 100 by a predetermined distance. At this time, the through hole 42b formed in the housing member 40 may be provided in a shape corresponding to the mounting portion 42a for installing the magnet 41, and has a larger width and height than the sensing magnet 100. may be provided.

In addition, a plurality of terminals 201 may be provided on the circuit board 200 . This terminal 201 is for applying a current to the coil unit 31 while outputting a detection signal of the position sensor 210 .

According to the present embodiment as described above, since the movement of the bobbin 30 in the optical axis direction can be fed back using the sensing magnet 100, the time required for the auto focusing operation can be shortened.

In addition, the coil unit 31 operates in a state where the coil unit 31 is wound around the bobbin 30, and a thin and light sensing magnet 100 is attached to the outer wall of the bobbin 30, and the magnetic force of the sensing magnet 100 can be sensed. Since the position sensor 210 is configured to be closely disposed on one side wall of the camera module, it is possible to perform the auto focusing function more precisely and quickly without fear of deterioration of response characteristics.

In addition, the center of the position sensor 210 and the center of the sensing magnet 100 may coincide, and the vertical length of the sensing magnet 100 (part magnetized in two) is longer than the sensing part of the position sensor 210. can be made long. In addition, since the surface of the sensing magnet 100 facing the position sensor 210 is magnetized into two parts, position detection may be possible.

In addition, the vertical length of the through hole 42b and/or the window 300 may be larger than the space of the sensing magnet 100 moving along the vertical direction of the bobbin 30 and/or the size of the position sensor 210. can

The position sensor 210 may be any sensor capable of detecting a position, such as a gyro sensor, an angular velocity sensor, an acceleration sensor, or a photo reflector.

The camera module may include the lens driving device configured as described above, the lens barrel 32 coupled to the bobbin 30, the image sensor 11, and the printed circuit board 10. At this time, the image sensor 11 is mounted on the printed circuit board 10 and may form a bottom surface of the camera module.

An infrared cut filter may be additionally installed on the base 20 at a position corresponding to the image sensor 11 and may be combined with the housing member 40 . In addition, the lower side of the housing member 40 may be supported. A separate terminal member may be installed on the base 20 to conduct electricity with the printed circuit board 10, or it is possible to integrally form the terminal using a surface electrode or the like. Meanwhile, the base 20 may function as a sensor holder to protect the image sensor 11, and in this case, a protrusion may be formed downward along a side surface of the base 20. However, this is not an essential configuration, and although not shown, a separate sensor holder may be disposed below the base 20 to perform its role.

Although the embodiments according to the present embodiment have been described above, this is only exemplary, and those skilled in the art will understand that various modifications and embodiments of equivalent scope are possible therefrom. Therefore, the true technical protection scope of this embodiment should be defined by the following claims.

10; Printed circuit board 11; image sensor
20; base 30; bobbin
31; coil unit 32; lens barrel
40; housing members 51, 52; Upper and lower elastic members
60; cover member 100; sensing magnet
110; Magnet mount 200; circuit board
210; Position sensor 300; window

Claims (16)

cover;
a bobbin disposed within the cover;
a coil disposed on the bobbin;
a driving magnet disposed between the coil and the cover;
a sensing magnet disposed on the bobbin; and
Includes a position sensor disposed to face the sensing magnet,
The cover includes a first sidewall and a second sidewall disposed opposite to each other, and a third sidewall and a fourth sidewall disposed opposite to each other,
The driving magnet is disposed on the first sidewall and the second sidewall of the cover,
The sensing magnet is disposed in one area of a side surface of the bobbin located in the same direction parallel to a part of the coil and an optical axis,
The sensing magnet does not overlap the third sidewall of the cover in a direction perpendicular to the optical axis. cover;
a bobbin disposed within the cover;
a coil disposed on the bobbin;
a driving magnet disposed between the coil and the cover;
a sensing magnet disposed on the bobbin; and
Includes a position sensor disposed to face the sensing magnet,
The cover includes a first sidewall and a second sidewall disposed opposite to each other, and a third sidewall disposed between two imaginary straight lines contacting the first sidewall and the second sidewall, respectively, and having an opening formed therein,
The driving magnet includes a first magnet disposed on the first sidewall of the cover and a second magnet disposed on the second sidewall of the cover;
The sensing magnet is disposed on a side surface of the bobbin located in the same direction parallel to a part of the coil and an optical axis,
The sensing magnet overlaps the opening of the third sidewall and the position sensor in a direction perpendicular to the optical axis. a cover comprising a side wall;
a bobbin disposed within the cover;
a coil disposed on the bobbin;
a driving magnet disposed between the coil and the sidewall of the cover;
a sensing magnet disposed on the bobbin;
a circuit board disposed on the sidewall of the cover; and
A position sensor disposed on the circuit board;
The sidewall of the cover includes a first sidewall and a second sidewall disposed opposite to each other, and a third sidewall disposed between two imaginary straight lines contacting the first sidewall and the second sidewall, respectively, and having an opening formed therein, ,
The driving magnet includes a first magnet disposed on the first sidewall of the cover and a second magnet disposed on the second sidewall of the cover;
The coil includes a first region overlapping the sensing magnet in an optical axis direction,
The drive magnet is not disposed between the first region of the coil and the third sidewall,
The sensing magnet overlaps the opening of the third sidewall in a direction perpendicular to the optical axis direction. a cover comprising a side wall;
Housing disposed within the cover
a bobbin disposed within the housing;
a coil disposed on the bobbin;
a driving magnet disposed between the coil and the sidewall of the cover;
a sensing magnet disposed on the bobbin; and
a circuit board having a position sensor facing the sensing magnet and including a plurality of terminals; and
Including an elastic member coupled to the housing and the bobbin,
The sidewall of the cover includes a first sidewall and a second sidewall disposed opposite to each other, and a third sidewall disposed between two imaginary straight lines contacting the first sidewall and the second sidewall, respectively, and having an opening formed therein, ,
A part of the coil overlaps the sensing magnet in the optical axis direction;
The sensing magnet overlaps the opening of the third sidewall of the cover in a first direction perpendicular to the optical axis direction, and
The elastic member includes a first area electrically connected to one end of the coil and a second area electrically connected to one of the plurality of terminals of the circuit board. According to claim 1 or 2,
Including a circuit board including a plurality of terminals,
The lens driving device wherein the position sensor is disposed on the circuit board. According to claim 2 or 3,
The first magnet and the second magnet are coupled to the cover by an adhesive. According to claim 5,
Including an elastic member coupled to the bobbin,
The elastic member is coupled to the circuit board and the lens driving device by solder. According to claim 5,
Includes a base coupled to the cover,
At least some of the plurality of terminals of the circuit board are exposed to the side of the base. According to claim 1 or 2,
The bobbin includes a recess formed on the side surface of the bobbin and in which the sensing magnet is disposed. According to claim 3 or 4,
The sensing magnet is disposed on the upper side of the coil in the optical axis direction. According to any one of claims 1 to 4,
The bobbin includes a protruding area protruding from an outer surface of the bobbin and an opening opening toward the coil,
At least a portion of the sensing magnet is disposed within the protrusion area. According to claim 5,
One end of the coil is coupled to the terminal of the circuit board by solder. According to claim 7,
The elastic member is coupled to at least one of the plurality of terminals of the circuit board by solder. According to claim 7,
The elastic member includes a first region coupled to one side of the coil by solder, and a second region coupled to one terminal of the circuit board by solder. According to claim 7,
The elastic member includes a first spring and a second spring,
The first spring includes a first region coupled to one side of the coil by solder, and a second region coupled to one terminal of the circuit board by solder,
The second spring includes a third region coupled to the other side of the coil by solder, and a fourth region coupled to the other terminal of the circuit board by solder. image sensor;
A printed circuit board on which an image sensor is mounted; and
A camera module comprising the lens driving device of any one of claims 1 to 4.

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