WO2015147385A1

WO2015147385A1 - Camera module having autofocus and optical image stabilization functions

Info

Publication number: WO2015147385A1
Application number: PCT/KR2014/007528
Authority: WO
Inventors: 장용훈; 정호준
Original assignee: 넥스타테크놀로지 주식회사
Priority date: 2014-03-25
Filing date: 2014-08-13
Publication date: 2015-10-01
Also published as: KR101421223B1

Abstract

The present invention relates to a camera module capable of adjusting a focal point of a subject by moving a lens in an optical axis direction through an interaction between a coil and a magnet and at the same time, carrying out image stabilization by also moving the lens in the horizontal direction, which is a camera module for performing an autofocus (AF) function by driving the lens in the optical axis direction (z axis) and performing an optical image stabilization (OIS) function by driving the lens on a plane (x-y plane) that is perpendicular to the optical axis (z axis), the camera module comprising: a base which has insertion grooves in each corner direction of the bottom surface thereof, and of which each side surface is open; OIS coil members which are inserted into the insertion grooves of the base and are wound on the x-y plane; a cover seated on the base, having open side surfaces, and having a space part formed therein; a carrier having an AF coil member wounded around the outer circumference thereof and having a lens module inserted thereinto and disposed in the space part of the cover so as to be movable in the optical axis direction; magnets attached to the open side surfaces of the cover and magnetized with different polarities at the inside and the outside of the cover, respectively; and a hook-shaped elastic member for elastically supporting the cover at the base by inserting one end thereof into the upper surface of the cover and coupling the other end thereof to the bottom surface of the base, wherein the magnets and the OIS coil members are disposed to be adjacent to each other in the optical axis direction so as to drive the cover and the carrier on the x-y plane by the magnetic force of the magnets in the optical axis direction, thereby performing the OIS function.

Description

Camera module with auto focus and image stabilization

The present invention relates to a camera module capable of correcting hand shake by moving the lens in the optical axis direction by controlling the focus of the subject by moving the lens in the optical axis direction by the interaction between the coil and the magnet.

Typically, the camera module has an image sensor, which is widely used in mobile devices such as mobile phones, notebook computers, portable degital assistance (PDA), cameras for inserting monitors, rear view cameras or interphones in automobiles.

In addition, since the recent camera module has a trend of miniaturization and light weight with very high pixels, the photographed image is sensitive to disturbance, resulting in distortion of the image.

In order to compensate for the distortion of such an image and to take a clear picture, an AF (Auto Focusing) function and an image stabilization (OIS, Optical Image Stabilization) function have been recently developed and commercialized.

In general, the autofocus function is exerted by moving the barrel containing the lens in the optical axis direction, and the image stabilization function is exerted by moving the lens horizontally on a plane perpendicular to the optical axis direction.

In particular, with respect to the image stabilization function, there is also a camera module which has a more accurate image stabilization function by applying a displacement in the optical axis direction (z-axis) rather than a simple parallel movement in a plane (xy plane) perpendicular to the optical axis direction. .

Among them, Patent Document 1 discloses a camera module for performing the above two functions by the same magnet without having a magnet related to the autofocus function and a magnet related to the camera shake correction function.

In the camera module disclosed in Patent Document 1, as shown in FIG. 1, a second coil member for performing an autofocus function is inserted into an insertion hole formed in the first coil member for performing a camera shake correction function and adjacent to the same magnet. It can be miniaturized by reducing the number of parts and simplifying the structure by arranging it in a simple manner. However, since the polarity for forming the magnetic field in the second coil member and the pole for forming the magnetic field in the first coil member must be provided separately, the magnet Has a long length and has a manufacturing disadvantage in that several magnets should be given to one magnet, and the magnetic fields acting on the first coil member and the second coil member overlap or cancel each other and move in the vertical and horizontal directions of the lens. There is a problem that the power required to be increased.

In addition, Patent Document 2, as shown in Fig. 2, the autofocus coil block facing the two magnets adjacent to each other in the mover including four magnets arranged on the outer peripheral surface of one bobbin, and the remaining adjacent It has a stator including a shake correction coil block facing each of the two magnets, the autofocus coil block moves the lens up and down due to the magnetic force of the magnet, the shake correction coil block is due to the magnetic force of the magnet Because it serves to move the left and right, it is supposed to perform both of the above functions, but since the coil blocks on the four sides are used separately for auto focusing and image stabilization, the driving force is low and to give the necessary driving force Magnets with a large number of turns of coils or magnetic force cannot be used There is no problem.

In order to solve the problems of the prior art as described above, an object of the present invention is to provide a camera module capable of smoothly performing an autofocus function and a camera shake correction function while reducing the number of magnets.

In addition, an object of the present invention is to provide a camera module having a fine and accurate image stabilization function by inducing the lens movement in the horizontal direction on the x-y plane to the displacement in the z-axis direction with a simple mechanical structure.

Camera module of the present invention having the above object, to perform the autofocus function (AF) by driving the lens in the optical axis direction (z axis), the lens on the plane (xy plane) perpendicular to the optical axis (z axis) A camera module for driving an image stabilization function (OIS), comprising: a base having a fitting groove formed in each corner direction of a bottom surface, each side of which is open; An OIS coil member inserted into the fitting groove of the base and wound in an x-y plane; A cover placed in the base and having an open side and having a space formed therein; A carrier disposed along the outer circumference of the AF coil member and disposed in the space portion of the cover to insert a lens module therein and move in an optical axis direction; A magnet attached to an open side of the cover and magnetized with different polarities inside and outside of the cover; And a hook-shaped elastic member having one end inserted into an upper surface of the cover and the other end coupled to a bottom surface of the base to elastically support the cover to the base. Including, The magnet and the OIS coil member is disposed adjacent to each other in the optical axis direction by driving the cover and the carrier on the xy plane by a magnetic force in the optical axis direction of the magnet to perform a hand shake correction function It is done.

In addition, an upper plate spring may be coupled to an upper surface of the cover, and a lower plate spring may be coupled to a lower surface of the carrier.

In addition, the bottom surface of the magnet and the OIS coil member is preferably spaced apart by a predetermined gap by an IR cap interposed between the lower spring and the OIS coil member.

On the other hand, the upper circumferential portion of the IR cap may support the lower spring to form a support protrusion for securing the elastic portion of the lower spring center, one end of the elastic member is formed through the first through hole formed in the upper spring Is inserted into the second through hole formed in the upper surface of the cover through the third through hole formed in the lower spring through the fourth through hole formed in the IR cap connected to the connection, the other end of the elastic member is the bottom of the base It is fixed to the coupling hole formed in the surface.

In addition, a plurality of upper protrusions are formed on an upper surface of the carrier, and the upper spring is formed with an upper coupling groove corresponding to the upper protrusion so that the upper protrusion is fitted into the upper coupling groove so that the cover moves horizontally. It is desirable to allow elastic restoration while moving together.

In addition, the magnet has the same polarity in the optical axis direction, the inner side of the cover is the N pole, the outer side is magnetized to the S pole, it is preferable to perform the autofocus function while the cover is moved upward by the AF coil member. Do.

According to the camera module according to the present invention having the configuration described above, the same magnet can be used to perform the autofocus function and the image stabilization function at the same time, the number of magnets by using the magnetic force in the z-axis direction from the magnet In addition, the lens movement in the horizontal direction on the xy plane can be reduced to the displacement in the z-axis direction due to a simple mechanical structure, thereby performing a fine and accurate image stabilization function.

1 is a perspective view of a conventional camera module disclosed in Patent Document 1,

2 is a perspective view of another conventional camera module disclosed in Patent Document 2;

3 is a perspective view showing an assembled state of a camera module according to an embodiment of the present invention;

4 is a cross-sectional view taken along line A-A of FIG.

5 is an exploded perspective view of FIG. 3;

6 is a perspective view showing a mechanism for performing an autofocus function;

7 is a perspective view showing a mechanism for performing a camera shake correction function,

8 is a perspective view illustrating an operating state of performing a camera shake correction function.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings through preferred embodiments.

The embodiments of the present invention can be modified in various forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. These embodiments are provided to explain in detail the present invention to those skilled in the art. Accordingly, the shape of each element shown in the drawings may be exaggerated to emphasize a more clear description.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are only used to distinguish one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to limit the technical scope of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

3 is a perspective view of the combination of the camera module according to an embodiment of the present invention, Figure 4 is a cross-sectional view A-A of Figure 3, Figure 5 is an exploded perspective view of the camera module of FIG.

In order to avoid duplication of explanation, the coupling relationship between the configurations of the camera module according to the embodiment of the present invention will be described with reference to the exploded perspective view of FIG. 5.

As shown in FIG. 5, the remaining components are accommodated in an internal space formed by the base 100.

The base 100 has a substantially rectangular shape when viewed in a plane (xy plane), and is fitted in such a manner that the bobbins on which the OIS coil member 200 and the OIS coil member are wound may be mounted together in the respective corner directions of the upper surface. The groove 110 is formed, and a support for performing a role of a frame extends in the upward direction near each corner.

The height of the upper support is approximately equal to the overall height of the camera module according to this embodiment.

The OIS coil member 200 is wound around a bobbin having a rod shape as a focusing body. The OIS coil member 200, which is a feature of the present invention, is arranged to allow current to flow in a loop present on the x-y plane.

IR cap 900 is a central hole is a plate-like. Each corner portion of the upper surface is formed with a support protrusion 910, each vertex portion is protruded to the outside somewhat, the protruding portion is formed with a fourth through hole 950, the elastic member (to be described later) One end of the 600 is connected through the fourth through hole 950 and may move in a horizontal direction together with the cover 300 to be described later.

The lower spring 800 is seated above the IR cap 900. At this time, the lower spring 800 is also a leaf spring, and is supported by the support protrusion 910 formed on the IR cap 900, the lower spring 800 is floating from the upper surface of the IR cap 900, As a result, the lower spring 800 is able to exert an elastic return force against displacement in the optical axis direction even when it is placed in the IR cap 900.

In addition, the bottom surface of the magnet 500 to be described later and the top surface of the OIS coil member 200 by the thickness of the IR cap can maintain a predetermined gap with each other. In addition, a third through hole 850 is formed at each corner of the lower spring 800, and one end of the elastic member 600 to be described later is connected to the fourth through hole 950.

* The carrier 400 is seated on the upper surface of the upper lower spring 800 is fixed.

In the carrier 400, the lens module L is inserted, and the AF coil member 450 is wound around the center of the outer circumferential surface thereof in a band shape.

Figure 5 is a lens module (L) and the frame of the carrier is screwed together to move integrally but shown in a separated state for convenience of explanation.

Four projections are formed on the circumferential surface of the upper surface of the carrier 400 for coupling with the upper spring, which will be described later, so that the carrier 400, the upper spring 700, and the lower spring 800 are fixed to each other and integrated. It works.

The cover 300 has a substantially rectangular shape when viewed in a plan view, and four legs are formed downward from each vertex, and both side and top surfaces are opened, and the upper carrier 400 is accommodated therein. There is this.

In addition, four second through holes 350 are formed through the legs of the cover so that one end of the elastic member 600 to be described later is inserted near the top vertex of the cover 300.

Magnets 500 are attached to each of the four open side surfaces of the cover 300, and a plate-shaped yoke as a focusing body is attached to the outer surface of the magnet 500.

The upper spring 700 is placed on the upper surface of the cover 300, the lower spring 800 is configured to be in contact with the bottom surface of the cover 300, the upper spring 700, the carrier 300 and the lower spring 800 ) Is fixed integrally, the cover 300 is only connected to the upper spring 700 and the lower spring 800 by the elastic member 600.

The magnet 500 is disposed to have a different polarity only in the x-axis and y-axis directions. That is, the magnet 500 according to the present exemplary embodiment does not necessarily have to be a single magnet when viewed based on any one side of the cover 300, but is arranged such that the same polarity is always given in the z-axis direction.

In addition, the magnet 500 is fixed to the legs of the cover 300, the polarized magnetized on the bottom of each magnet 500 is disposed to face each cross section of the OIS coil member 200.

The upper spring 700 has an upper coupling groove 710 formed to correspond to the upper protrusion 410 formed in the upper carrier 400 so as to be integrally coupled to the carrier 400 and the cover 300. It is installed at the height settled on the upper surface of).

In addition, the first through hole 750 is also formed near each vertex of the upper spring 700, and one end of the elastic member 600, which will be described later, becomes the first insertion hole.

The upper spring 700 is also a plate-like spring that allows the central portion to exert an elastic force, similar to the lower spring 800, and performs a function of allowing the carrier 400 to return due to its restoring force after moving upward. It is to perform the function of limiting the displacement width in the up and down direction of the carrier 400.

Next, as shown in FIG. 5, the elastic member 600 has a hook shape. One end of the elastic member 600 is the first through hole 750 of the upper spring 700, the second through hole 350 of the cover 300, the third through hole 850 of the lower spring 800 and IR The upper spring 700, the cover 300, the lower spring 800 and the IR cap 900 are connected to the fourth through hole 950 of the cap 900 in order, and the other end is directly the base 100. It is fixed to the insertion hole 150 formed in the bottom surface of the.

The operation between the components will be described below.

1.Operation of AF

6 illustrates a process of performing an autofocus function of the camera module according to the present embodiment.

One magnet 500a of the four magnets 500 attached to the side of the cover 300 will be described based on the magnet 500a.

In the optical axis direction, the upper direction is defined as the positive z-axis direction, the plane perpendicular to the optical axis is defined as the x-y plane, and the left direction is defined as the x-axis positive direction and the right direction as the y-axis positive direction.

Around the inside of the cover 300, the magnet 500a is magnetized to the north pole and the south pole in the positive y-axis direction. Since the line of magnetic force comes from the surface of the N pole of the magnet 500a, the direction of the magnetic force is directed in the direction of the y-axis negative, and the current is in the x-axis negative direction to the AF coil member 450 wound along the outer circumferential surface of the carrier 400. When a voltage is applied from the controller (not shown) to flow, force is generated in the positive z-axis direction by the left-hand rule of Fleming, which causes the carrier 400 to adjust the focus while moving upward.

2. OIS (Stabilizer)

The biggest feature of the present invention is that it is possible to perform the image stabilization at the same time with the auto focus using the magnetic force generated in the same magnet, perform the OIS function using the magnetic force generated in the z-axis direction of the magnetic force generated from the same magnet Is that.

7 is a diagram illustrating an operation of performing an OIS function.

For convenience of description, unlike the magnet 500a of FIG. 6, the magnet of FIG. 7 will be described based on a magnet 500b having a good bottom surface and an OIS coil member 200a disposed opposite thereto.

The bottom surface of the magnet 500b is also magnetized to the north pole and the south pole in the y-axis negative direction, and the magnetic force lines emerge in a direction perpendicular to the bottom of the magnet 500b, that is, in the z-axis negative direction.

At this time, the OIS coil member 200 of the present embodiment is wound on the xy plane, and when the power is applied from the controller (not shown) so that the current flows in the clockwise direction on the xy plane, the inner member of the OIS coil member 200a Current flows in the x-axis positive direction at 200a ', and current flows in the x-axis negative direction at the outer member 200a ".

In addition, the upper surface of the inner member 200a 'of the OIS coil member 200a faces the N pole of the magnet 500b, and the upper surface of the outer member 200a "of the OIS coil member 200a is of the magnet 500b. Opposite the S pole.

Then, the magnetic force acts in the negative direction of the z-axis to the inner member 200a 'of the OIS coil member 200a, and toward the S pole toward the outer member 200a "of the OIS coil member 200a, that is, z Since the magnetic force acts in the positive direction of the axis, Fleming's left-hand law causes the electromagnetic force to act in the positive direction of the y axis.

Therefore, the shake correction function is performed by a mechanism in which the cover 300 in which the carrier 400 is accommodated, including the magnet 500, is moved in the positive y-axis direction.

This indicates that the electromagnetic force may act in the x-axis positive direction, the y-axis positive direction, the x-axis negative direction, or the y-axis negative direction depending on the direction of the current and the direction of the polarity. ) Polarity in the z-axis direction is the same, and if the OIS coil member 200 is wound on the xy plane means that it can move in a plane perpendicular to the optical axis (z-axis).

At this time, one end of the elastic member 600, as described above, the first through hole 750 of the upper spring 700, the second through hole 350 of the cover 300, the third of the lower spring 800 It passes through the through hole 850 and the fourth through hole 950 of the IR cap 900 in order to connect the upper spring 700, the cover 300, the lower spring 800 and the IR cap 900, Since the other end is inserted and fixed only in the coupling hole 150 formed on the bottom surface of the base 100 directly, the base 100 is fixed to the rest of the cover 300, the carrier 400, the upper spring 700 ), The lower spring 800 and the IR cap 900 are all moved in the horizontal direction to compensate for camera shake.

8 is a diagram showing a movement path of the camera module in this embodiment. That is, the camera module according to the present embodiment does not compensate for hand shake by simply moving in the horizontal direction, but the base 100 is fixed due to the elastic member 600 and all remaining components mounted thereon are moved in the horizontal direction. Therefore, it is possible to prevent camera shake by synthesizing a motion component in the vertical direction, not a simple linear motion on the xy plane.

The above has been described the camera module of the present invention through a preferred embodiment, which is intended to help the understanding of the present invention is not intended to limit the technical scope to the matters described in the embodiments and drawings.

Those skilled in the art will appreciate that various modifications and variations are possible within the technical scope of the present invention and that they are also within the technical scope of the present invention.

For example, although the polarity of the magnet 500 of the present invention is illustrated and described as the north pole and the south pole from the inside to the outside, the polarity may be changed and the cover 300 may be changed as long as there is no change in the polarity in the z-axis direction. Of course, the number of magnets attached to each side of the can also be more than one.

Claims

Camera that performs auto focus function (AF) by driving the lens in the optical axis direction (z axis), and performs camera shake correction function (OIS) by driving the lens on a plane (xy plane) perpendicular to the optical axis (z axis) In the module,

A fitting groove 110 is formed in each corner direction of the bottom surface, and each side of the base 100 is opened;

An OIS coil member 200 inserted into the fitting groove 110 of the base 100 and wound in an x-y plane;

A cover 300 placed in the base 100 and having a side open and having a space formed therein;

An AF coil member 450 is wound along an outer circumferential surface thereof, and a carrier module 400 is disposed in the space portion of the cover 300 so that the lens module L is inserted therein and movable in the optical axis direction;

A magnet 500 attached to an open side of the cover 300 and magnetized with different polarities inside and outside of the cover 300;

One end is inserted into the upper surface of the cover 300 and the other end is coupled to the bottom surface of the base 100 hook-shaped elastic member 600 for elastically supporting the cover 300 to the base 100 ; And

A plate-shaped lower spring 800 coupled to a bottom surface of the carrier 400; Including,

The magnet 500 and the OIS coil member 200 are disposed adjacent to each other in the optical axis direction, so that the cover 300 and the carrier 400 are in xy plane by a magnetic force in the optical axis direction of the magnet 500. To stabilize the camera,

A bottom surface of the magnet 500 and an upper surface of the OIS coil member 200 are spaced apart by a predetermined gap by an IR cap 900 interposed between the lower spring 800 and the OIS coil member 200. Camera module with auto focus and image stabilization.
The method of claim 1,

The upper surface of the cover is a camera module having an autofocus function and image stabilization function characterized in that the upper plate 700 coupled to the plate.
The method of claim 2,

The auto focusing function and the image stabilization are characterized in that the upper peripheral portion of the IR cap (900) supports the lower spring (800) so that a support protrusion (910) for securing the elasticity of the central portion of the lower spring (800) is formed. Camera module with functions.
The method of claim 3,

One end of the elastic member 600 is inserted into the second through hole 350 formed on the upper surface of the cover 300 through the first through hole 750 formed in the upper spring 700 and the lower spring 800. ) Penetrates through the third through hole 850 formed therein to the fourth through hole 950 of the IR cap 900, and the other end of the elastic member 600 is connected to the base 100 of the base 100. Camera module having an autofocus function and image stabilization function, characterized in that fixed to the coupling hole 150 formed on the bottom surface.
The method according to claim 1 or 2,

A plurality of upper protrusions 410 are formed on an upper surface of the carrier 400, and an upper coupling groove 710 corresponding to the upper protrusions 410 is formed on the upper spring 700 so that the upper protrusions 410. ) Is a camera module having an auto focusing function and a camera shake correction function, characterized in that is fitted into the upper coupling groove (710).
The method according to any one of claims 1 to 4,

The magnet 500 has the same polarity in the optical axis direction (z-axis direction), and the inner side of the cover 300 is the N pole, and the outer side is magnetized to the S pole. Camera module having a.