Patent ID: 12210168

Throughout the drawings and the detailed description, unless otherwise described or provided, the same drawing reference numerals will be understood to refer to the same elements, features, and structures. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience.

DETAILED DESCRIPTION

The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the systems, apparatuses and/or methods described herein will be apparent to one of ordinary skill in the art. The progression of processing steps and/or operations described is an example; however, the sequence of and/or operations is not limited to that set forth herein and may be changed as is known in the art, with the exception of steps and/or operations necessarily occurring in a certain order. Also, descriptions of functions and constructions that are well known to one of ordinary skill in the art may be omitted for increased clarity and conciseness.

The features described herein may be embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art.

Throughout the specification, it will be understood that when an element, such as a layer, region or wafer (substrate), is referred to as being “on,” “connected to,” or “coupled to” another element, it can be directly “on,” “connected to,” or “coupled to” the other element or other elements intervening therebetween may be present. In contrast, when an element is referred to as being “directly on,” “directly connected to,” or “directly coupled to” another element, there may be no elements or layers intervening therebetween. Like numerals refer to like elements throughout. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.

It will be apparent that though the terms first, second, third, etc. may be used herein to describe various members, components, regions, layers and/or sections, these members, components, regions, layers and/or sections should not be limited by these terms. These terms are only used to distinguish one member, component, region, layer or section from another region, layer or section. Thus, a first member, component, region, layer or section discussed below could be termed a second member, component, region, layer or section without departing from the teachings of the exemplary embodiments.

Spatially relative terms, such as “above,” “upper,” “below,” and “lower” and the like, may be used herein for ease of description to describe one element's relationship to another element(s) as shown in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “above,” or “upper” other elements would then be oriented “below,” or “lower” the other elements or features. Thus, the term “above” can encompass both the above and below orientations depending on a particular direction of the figures. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein may be interpreted accordingly.

The terminology used herein is for describing illustrated embodiments only and is not intended to be limiting of the present description. As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” and/or “comprising” when used in this specification, specify the presence of stated features, integers, steps, operations, members, elements, and/or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, members, elements, and/or groups thereof.

Hereinafter, various embodiments will be described with reference to schematic views. In the drawings, for example, due to manufacturing techniques and/or tolerances, modifications of the shape shown may be estimated. Thus, embodiments of the present description should not be construed as being limited to the particular shapes of regions shown herein, for example, to include a change in shape results in manufacturing. The following embodiments may also be constituted by one or a combination thereof.

The contents of the embodiments described below may have a variety of configurations and propose only a required configuration herein, but are not limited thereto.

The following description relates to a lens driving apparatus and a camera module including the same. The lens driving apparatus and camera module may be applied to portable electronic devices such as mobile communications terminals, smartphones, tablet PCs, and the like.

A camera module is an optical device for capturing still or moving images. A camera module may include a lens that refracts light reflected from a subject and a lens driving apparatus that moves the lens in order to adjust a focus or to compensate for the shaking of the camera module while images are captured.

FIG.1is a perspective view of an example of a camera module, andFIG.2is a schematic exploded perspective view of the camera module.

Referring toFIGS.1and2, the camera module1000includes a lens barrel200, a lens driving apparatus500, an image sensor unit600, a housing120and a case110. The housing120and the case110accommodate the lens barrel200and the lens driving apparatus500therein. The lens driving apparatus500moves the lens barrel200within the housing120and the case110. The image sensor unit600converts light incident through the lens barrel200into an electrical signal.

In this example, the lens barrel200has a hollow cylindrical shape so that a plurality of lenses for capturing an image of the subject may be accommodated therein, and the plurality of lenses is provided in the lens barrel200on an optical axis.

The number of lenses in the lens barrel200may be varied depending on a design of the lens barrel200, and the respective lenses may have optical characteristics such as the same refractive index, different refractive indices, or the like.

The lens driving apparatus500may be an apparatus moving the lens barrel200.

For example, the lens driving apparatus500may adjust a focus by moving the lens barrel200in an optical axis direction (a Z-axis direction) and compensate for the shaking of the camera module1000at the time of capturing images by moving the lens barrel200in directions perpendicular to the optical axis (a Z-axis).

The lens driving apparatus500includes a focus adjustment unit300for adjusting the focus and a shake compensation unit400for compensating for the shaking of the camera.

The image sensor unit600may be an apparatus that converts the light incident through the lens barrel200into an electrical signal.

In this example, the image sensor unit600includes an image sensor610and a printed circuit board620connected to the image sensor610, and may further include an IR filter.

The IR filter may serve to block light in an infrared region in the light incident through the lens barrel200.

The image sensor610may convert the light incident through the lens barrel200into an electrical signal. For example, the image sensor610may be a charge coupled device (CCD) or a complementary metal-oxide semiconductor (CMOS).

The electrical signal converted by the image sensor610may be output as an image through a display unit of the portable electronic device.

The image sensor610may be attached to the printed circuit board620and electrically connected to the printed circuit board620by a wire bond.

The lens barrel200and the lens driving apparatus500are accommodated in the housing120.

In this example, upper and lower portions of the housing120include openings, and the lens barrel200and the lens driving apparatus500are accommodated in an internal space of the housing120.

The image sensor unit600is disposed below the housing120.

The case110may be coupled to the housing120to enclose an outer surface of the housing120, and serve to protect internal components of the camera module.

Further, the case110may serve to block electromagnetic waves.

For example, the case110may block electromagnetic waves so that electromagnetic waves generated in the camera module do not affect other electronic component in the portable electronic device.

Further, because various electronic components in addition to the camera module are mounted in the portable electronic device, the case110may block electromagnetic waves so that electromagnetic waves generated in these electronic components may not affect the overall camera module1000.

The case110may be formed of a metal to thereby be grounded via a ground pad provided in the printed circuit board620, such that the case110may block the electromagnetic wave.

FIG.3is a cross-sectional view taken along line A-A′ ofFIG.1, andFIG.4is a schematic enlarged view of part B ofFIG.3.

In addition,FIG.5is a partially exploded perspective view of the camera module according to the example illustrated inFIG.2.

The focus adjustment unit300of the lens driving apparatus500will be described with reference toFIGS.3through5.

The lens barrel200may be moved inside the lens driving apparatus500in order to adjust the camera lens to be in focus on a subject.

For instance, referring to the example illustrated inFIGS.3through5, the focus adjustment unit300may move the lens barrel200in the optical axis direction (the Z-axis direction) in order to adjust the lens to be in focus on a subject.

In this example, the focus adjustment unit300includes a carrier310that accommodates the lens barrel200therein and a focus adjustment driving part that generates a driving force to move the lens barrel200and the carrier310in the optical axis direction (the Z-axis direction).

The focus adjustment driving part includes a magnet320aand a coil330a.

Referring toFIG.4, the magnet320ais mounted on one side surface of the carrier310.

In this example, the coil330ais attached to the housing120via a board130. Referring toFIG.3, the coil330ais mounted on the board130on an opposing surface of the housing120from a coil452of the shake compensation unit400.

The magnet320amay be a movable structure mounted on the carrier310and moving together with the carrier310in the optical axis direction (the Z-axis direction), and the coil330amay be a stationary structure attached to the housing120. However, positions of the magnet320aand the coil330aare not limited thereto, but may be exchanged with each other.

When power is applied to the coil330a, the carrier310may be moved in the optical axis direction (the Z-axis direction) by electromagnetic interaction between the magnet320aand the coil330a.

Because the lens barrel200is accommodated inside the carrier310, the lens barrel200may also be moved in the optical axis direction (the Z-axis direction) by moving the carrier310.

While the carrier310is moving in the optical axis direction (the Z-axis direction), a rolling member370disposed between the carrier310and the housing120is used to decrease friction between the carrier310and the housing120. In this example, the rolling member370has a ball shape.

The rolling member370may be disposed on both sides of the magnet320a, as illustrated inFIG.5.

A first yoke350may be disposed in the housing120. Referring toFIG.4, the first yoke350is disposed on an inner side surface of the housing120to face the magnet320awith the coil330ainterposed therebetween.

An attractive force may act between the first yoke350and the magnet320ain a direction perpendicular to the optical axis (the Z-axis).

Therefore, the rolling member370may maintain a state of contact with the carrier310and the housing120due to the attractive force between the first yoke350and the magnet320a.

In addition, the first yoke350may serve to focus the magnetic force of the magnet320a. Therefore, the generation of leakage magnetic flux may be prevented.

The first yoke350and the magnet320amay form a magnetic circuit.

According to one example, a length of the first yoke350in the optical axis direction (the Z-axis direction) may be longer than that of the magnet320ain the optical axis direction (the Z-axis direction).

In the event that the length of the first yoke350in the optical axis direction (the Z-axis direction) is set to be shorter than that of the magnet320ain the optical axis direction (the Z-axis direction), when the magnet320amoves in the optical axis direction (the Z-axis direction), attractive force acting on the center of the magnet320ato direct the magnet320atoward the center of the first yoke350may be increased.

Therefore, restoring force of the magnet320ato allow the magnet320ato return to an original position may be further increased, such that an amount of current required in order to move the magnet320amay be increased, and power consumption may be increased.

However, in an example in which the length of the first yoke350in the optical axis direction (the Z-axis direction) is longer than that of the magnet320ain the optical axis direction (the Z-axis direction), because the attractive force acting on the center of the magnet320ato direct the magnet320atoward the center of the first yoke350is relatively decreased, power consumption may be relatively decreased.

Meanwhile, a second yoke340is disposed between the carrier310and the magnet320a.

The second yoke340may serve to focus magnetic force of the magnet320a, thereby preventing the generation of leakage magnetic flux.

The second yoke340and the magnet320amay form a magnetic circuit.

In this example, a closed loop control method of sensing a position of the lens barrel200is used to provide feedback regarding the positon of the lens barrel200.

Therefore, a position sensor360may be required for the closed loop control. The position sensor360may be a hall sensor.

The position sensor360may be disposed at an inner side or outer side of the coil330a, and mounted on the board130on which the coil330ais mounted.

In addition, the position sensor360may be formed integrally with a circuit element (as an example, Driver IC) providing a driving signal to the focus adjustment unit300(seeFIG.5). However, the position sensor360is not limited thereto, and the position sensor360and the circuit element may be provided as separate components, respectively.

When the camera module is turned on, the position sensor360may sense an initial position of the lens barrel200. In addition, the lens barrel200may be moved from the sensed initial position to an initial setting position. The initial position may be a position of the lens barrel200in the optical axis direction when the camera module is turned on, and the initial setting position may be a position of the lens barrel200at which a focal length of the lens barrel200becomes infinite.

The lens barrel200may be moved from the initial setting position to a target position by a driving signal of the circuit element.

During the adjustment of the focus, the lens barrel200may be moved forwards and backwards along the optical axis direction (the Z-axis direction). This is, the lens barrel200may be bi-directionally moved along the optical axis direction (the Z-axis direction).

In order to secure sufficient driving force at the time of adjusting the focus, a magnet320band a coil330bmay be additionally utilized.

In the event that a mount area for a magnet is decreased in order to produce a slim camera module, it is possible that a size of the magnet may be also decreased so that it becomes difficult to secure a sufficient driving force.

However, according to the example provided above, the magnets320aand320bmay be attached to different surfaces of the carrier310, respectively, and the coils330aand330bmay be provided on different surfaces of the housing120, respectively, to face the magnets320aand320b, respectively, such that sufficient driving force required for focus adjustment may be secured even when the camera module is reduced in size to product a slim electronic product.

FIG.6is a schematic perspective view illustrating another example of a focus adjustment unit of a lens driving apparatus.

Referring toFIG.6, any one magnet of a plurality of magnets320aand320bmounted on different surfaces of the carrier310may face a coil330a, and the other magnet thereof may face a position sensor360.

In the example illustrated inFIG.6, the magnet320afaces the coil330a, and the magnet320bfaces a position sensor360. Therefore, the magnet320amay serve as a driving magnet, and the magnet320bmay serve as a sensing magnet.

Further, because the coil330aand the position sensor360are disposed on different surfaces of the housing120to be spaced apart from each other, a larger space may be secured to mount the coil330a. Therefore, the number of turns for the coil330amay be increased, and thus, driving force may be improved.

In addition, because the coil330aand the position sensor360are disposed on different surfaces of the housing120to be spaced apart from each other, an influence of an electric field of the coil330aon the position sensor360may be significantly decreased. Therefore, sensing accuracy of the position sensor360may be improved.

FIGS.7and8illustrate exploded perspective views of an example of a shake compensation unit according toFIG.2.

The shake compensation unit400is used in order to correct image blurring or image distortion caused due to factors such as the shaking of a user's hand at the time of capturing still or moving images.

For example, at the time an image is captured, in the event that the camera is shaken by the instability of a user's hand or the like, the shake compensation unit400may impart relative displacement corresponding to the shaking of the hand to the lens barrel200in order to correct the blurring.

In order to compensate for the shaking of the camera module, the shake compensation unit400may move the lens barrel200in directions that are perpendicular to the optical axis (the Z-axis).

Referring toFIGS.7and8, the shake compensation unit400includes a guide member that guides the movement of the lens barrel200, and a shake compensation driving part that generates a driving force to move the guide member in directions that are perpendicular to the optical axis (the Z-axis).

In this example, the guide member includes a frame410and a lens holder420. The frame410and the lens holder420are inserted into the carrier310to thereby be disposed in the optical axis direction (the Z-axis direction), and serve to guide the movement of the lens barrel200.

The frame410and the lens holder420both include spaces or openings into which the lens barrel200may be inserted (seeFIG.2). The lens barrel200may be attached to the lens holder420so that the lens barrel200and the lens holder410moves together.

The frame410and the lens holder420may be moved inside the carrier310in a direction perpendicular to the optical axis (the Z-axis) by driving force generated in the shake compensation driving part.

The shake compensation driving part includes first and second shake compensation driving parts440and450, and the first and second shake compensation driving parts440and450include magnets441and451and coils442and452, respectively.

The first shake compensation driving part440may generate driving force in a first axis direction (an X-axis direction) perpendicular to the optical axis (the Z-axis), and the second shake compensation driving part450may generate driving force in a second axis direction (a Y-axis direction) perpendicular to the first axis (the X-axis).

In this example, the second axis (the Y-axis) is an axis perpendicular to both the optical axis (the Z-axis) and the first axis (the X-axis).

The first and second shake compensation driving parts440and450are disposed to be orthogonal to each other on a plane perpendicular to the optical axis (the Z-axis). For example, the magnet441of the first shake compensation driving part440and the magnet451of the second shake compensation driving part450are disposed to be orthogonal to each other on the plane perpendicular to the optical axis (the Z-axis).

The magnets441and451of the first and second shake compensation driving parts440and450are mounted on the lens holder420, and the coils442and452facing the magnets441and451, respectively, are mounted on the housing120. For convenience of explanation,FIGS.7and8illustrate an example in which the coils442and452are disposed toward the carrier310. However, as illustrated inFIG.2, the coils442and452may be attached to the housing120via the board130.

The magnets441and451may be movable structures that move together with the lens holder420in the directions perpendicular to the optical axis (the Z-axis), and the coils442and452may be stationary structures attached to the housing120. However, the arrangements of the magnets441and451and the coils442and452are not limited thereto, but positions thereof may be interchangeable.

Meanwhile, a plurality of ball members supporting the shake compensation unit400are provided. The plurality of ball members may serve to guide the frame410and the lens holder420to compensate for the shaking of the camera. In addition, the plurality of ball members may serve to maintain intervals between carrier310, the frame410, and the lens holder420.

The plurality of ball members include first and second ball members700and800.

The first ball members700guide movement of the shake compensation unit400in the first axis direction (the X-axis direction), and the second ball members800guide movement of the shake compensation unit400in the second axis direction (the Y-axis direction).

For example, in response to a driving force being generated in the first axis direction (the X-axis direction), the first ball members700may be moved in a rolling motion in the first axis direction (the X-axis direction). Therefore, the first ball members700may guide the movement of the frame410and the lens holder420in the first axis direction (the X-axis direction).

Further, in response to a driving force being generated in the second axis direction (the Y-axis direction), the second ball members800may be moved in a rolling motion in the second axis direction (the Y-axis direction). Therefore, the second ball members800may guide the movement of the lens holder420in the second axis direction (the Y-axis direction).

The first ball members700include a plurality of ball members disposed between the carrier310and the frame410, and the second ball members800include a plurality of ball members disposed between the frame410and the lens holder420.

Referring toFIG.7, first guide grooves710a,710b,710c,720a,720b, and720cthat accommodate the first ball members700therein are formed in surfaces of the carrier310and the frame410facing each other in the optical axis direction (the Z-axis direction), respectively. The first guide grooves710a,710b,710c,720a,720b, and720cinclude a plurality of guide grooves.

The first ball members700are accommodated in the first guide grooves710a,710b,710c,720a,720b, and720cto thereby be inserted between the carrier310and the frame410.

Because the first ball members700are accommodated in the first guide grooves710a,710b,710c,720a,720b, and720, the movement of the first ball members700is restricted in the optical axis direction (the Z-axis direction) and the second axis direction (the Y-axis direction). Thus, the first ball members700are movable only in the first axis direction (the X-axis direction). For example, the first ball members700may move in a rolling motion only in the first axis direction (the X-axis direction).

To this end, a plan view shape of each of the plurality of first guide grooves710a,710b,710c,720a,720b, and720cmay be a rectangle of which a length in the first axis direction (the X-axis direction) is longer than a width thereof in the second axis direction (the Y axis direction).

Further, a cross-sectional shape of some of the plurality of first guide grooves710a,710b,710c,720a,720b, and720cmay be different from that of the other guide grooves.

For example, a cross sectional shape of some guide grooves710band720bof the plurality of first guide grooves710a,710b,710c,720a,720b, and720cmay be substantially ‘∪’ shape, but a cross-sectional shape of the other guide grooves710a,710c,720a, and720cmay be substantially ‘v’ shape.

In this example, the guide grooves710band720bhaving a substantially ‘∈’ shaped cross section are guide grooves disposed to be farthest away from third guide grooves910and920among the plurality of first guide grooves710a,710b,710c,720a,720b, and720c(seeFIGS.7,8, and13).

Referring toFIG.8, second guide grooves810a,810b,810c,820a,820b, and820cthat accommodate the second ball members800therein are formed in surfaces of the frame410and the lens holder420facing each other in the optical axis direction (the Z-axis direction), respectively. The second guide grooves810a,810b,810c,820a,820b, and820cinclude a plurality of guide grooves.

The second ball members800are accommodated in the second guide grooves810a,810b,810c,820a,820b, and820cand are thereby inserted between the frame410and the lens holder420.

Because the second ball members800are accommodated in the second guide grooves810a,810b,810c,820a,820b, and820c, the movement of the second ball members800is restricted in the optical axis direction (the Z-axis direction) and the first axis direction (the X-axis direction). Thus, the second ball members800are only movable in the second axis direction (the Y-axis direction). For example, the second ball members800may move in a rolling motion only in the second axis direction (the Y-axis direction).

To this end, a plan view shape of each of the plurality of second guide grooves810a,810b,810c,820a,820b, and820cmay be a rectangle of which a length in the second axis direction (the Y-axis direction) is longer than a width thereof in the first axis direction (the X axis direction).

Further, a cross-sectional shape of some of the plurality of second guide grooves810a,810b,810c,820a,820b, and820cmay be different from that of the other guide grooves.

For example, a cross sectional shape of some guide grooves810band820bamong the second guide grooves810a,810b,810c,820a,820b, and820cmay be substantially ‘∈’ shape, but a cross-sectional shape of the other guide grooves810a,810c,820a, and820cmay be substantially ‘v’ shape.

In this example, the guide grooves810band820bhaving a substantially ‘∈’ shaped cross section are guide grooves disposed to be farthest away from the third guide grooves910and920among the plurality of second guide grooves810a,810b,810c,820a,820b, and820c(seeFIGS.7,8, and14).

Meanwhile, a third ball member900supporting movement of the lens holder420is provided between the carrier310and the lens holder420.

The third ball member900may guide movement of the lens holder420in both the first axis direction (the X-axis direction) and the second axis direction (the Y-axis) direction.

For example, in response to a driving force being generated in the first axis direction (the X-axis direction), the third ball member900may move in a rolling motion along the first axis direction (the X-axis direction). Therefore, the third ball member900may guide movement of the lens holder420in the first axis direction (the X-axis direction).

Further, in response to a driving force being generated in the second axis direction (the Y-axis direction), the third ball member900may move in a rolling motion along the second axis direction (the Y-axis direction). Therefore, the third ball member900may guide movement of the lens holder420in the second axis direction (the Y-axis direction).

Meanwhile, the second and third ball members800and900may support the lens holder420while coming into contact with the lens holder420. In this example, the second and third ball members800and900are positioned on different planes to each other (seeFIGS.8and11A through12B).

Referring toFIG.8, the magnets441and451of the first and second shake compensation driving parts440and450are provided on the lens holder420, and the second and third ball members800and900are positioned on both sides of the respective magnets441and451, respectively.

That is, the respective magnets441and451of the first and second shake compensation driving parts440and450are positioned between the ball members positioned on different planes from each other.

The third guide grooves910and920accommodating the third ball member900therein are formed in surfaces of the carrier310and the lens holder420facing each other in the optical axis direction (the Z-axis direction), respectively.

The third ball member900is accommodated in the third guide grooves910and920to thereby be inserted between the carrier310and the lens holder420.

Because the third ball member900is accommodated in the third guide grooves910and920, the movement of the third ball member900is restricted in the optical axis direction (the Z-axis direction), but the third ball member900may move in the rolling motion in both the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction).

To this end, a plan view shape of the third guide grooves910and920may be circular. Therefore, the plan view shape of the third guide grooves910and920and the plan view shapes of the first guide grooves710a,710b,710c,720a,720b, and720cand the second guide grooves810a,810b,810c,820a,820b, and820cdiffer from each other.

As a result, the first ball members700are movable in the rolling motion along the first axis direction (the X-axis direction), and the second ball members800are movable in the rolling motion along the second axis direction (the Y-axis direction). The third ball member900is movable in the rolling motion along both the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction).

Accordingly, a degree of freedom permitted for some of the plurality of ball members supporting the shake compensation unit400differ from a degree of freedom permitted for the remaining ball members.

Referring toFIG.9, a degree of freedom of an object may correspond to the number of independent variables required to indicate a movement state of the object in a three-dimensional coordinate system.

Generally, a degree of freedom of an object in a three-dimensional coordinate system is 6. The movement of the object may be represented by an orthogonal coordinate system in three directions and a rotary coordinate system in three directions.

For example, the object may move in a translational motion in each of the axis directions (the X-axis direction, the Y-axis direction, and the Z-axis direction) and move in a rotational motion with respect to each of the axes (the X-axis, the Y-axis, and the Z-axis).

In the present specification, the degree of freedom may refer to the number of independent variables required to indicate movement of the first to third ball members700,800, and900when the shake compensation unit400is moving due to a driving force generated in the directions perpendicular to the optical axis (the Z-axis) by power applied to the shake compensation unit400.

For example, the third ball member900may move in a rolling motion in two axis directions (the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction)) (seeFIG.15C), while the first and second ball members700and800may move in a rolling motion along one axis direction, which may be the first axis direction (the X-axis direction) or the second axis direction (the Y-axis direction) (seeFIGS.15A and15B) in response to a driving force generated in a direction perpendicular to the optical axis (the Z-axis).

Therefore, in this example, the degree of freedom of the third ball member900is greater than those of the first and second ball members700and800.

The movement of the first to third ball members700,800, and900in response to a driving force generated in a direction perpendicular to the optical axis (the Z-axis) will be described with reference toFIGS.10through12B.

In response to a driving force Fx being generated in the first axis direction (the X-axis direction) as illustrated inFIG.11B, the frame410and the lens holder420may move together in the first axis direction (the X-axis direction).

The first and third ball members700and900may move in a rolling motion in the first axis direction (the X-axis direction) to allow the lens holder420to move in the first axis direction (the X-axis direction). In this example, the movement of the second ball members800is restricted in the first axis direction (the X-axis direction).

Further, in response to a driving force Fy being generated in the second axis direction (the Y-axis direction) as illustrated inFIG.12B, the lens holder420may move in the second axis direction (the Y-axis direction).

The second and third ball members800and900may move in a rolling motion in the second axis direction (the Y-axis direction). In this example, the movement of the first ball member700is restricted in the second axis direction (the Y-axis direction).

The rotation of the frame410and the lens holder420based on the optical axis (the Z-axis) may be prevented by restricting the movement of some of the ball members as described above while a compensation is being performed for camera instability.

Because the inadvertent shaking of the camera module rapidly occurs at a rate of several ten Hz per second, the shake compensation unit400may be continuously moved in the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction). Therefore, because it is difficult to allow driving force generated in the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction) to be continually applied to the center of the shake compensation unit400, there is a risk that the shake compensation unit400will be rotated based on the optical axis (the Z-axis) during the compensation to remove the effect of the shaking of the camera module.

For example, in the event that all of the ball members are configured to be movable in a rolling motion in both the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction), there is a risk that the shake compensation unit400will be rotated about the optical axis (the Z-axis), which may deteriorate image quality.

However, according to the example illustrated inFIGS.7and9, the movement of some of the ball members is restricted during the compensation of the camera shaking, such that a rotation of the shake compensation unit400about the optical axis (the Z-axis) may be prevented by a mechanical structure.

Meanwhile, when ball members moved in the rolling motion in the first axis direction (the X-axis direction) are referred to as the first ball members and ball members moved in the rolling motion in the second axis direction (the Y-axis direction) are referred to as the second ball members, the ball member (the above-mentioned third ball member900) disposed between the carrier310and the lens holder420may serve as the first ball member when the shake compensation unit400is moved in the first axis direction (the X-axis direction), and serve as the second ball member when the shake compensation unit400is moved in the second axis direction (the Y-axis direction).

Therefore, in this example, the first and second ball members may share the third ball member with each other.

In the lens driving apparatus500, the closed loop control method of sensing the position of the lens barrel200to provide the feedback may be used to compensate for the shaking of the camera.

Therefore, position sensors443and453for a closed loop control may be provided. In the example illustrated inFIGS.8and10, the position sensors443and453are disposed inside the coils442and452of the first and second shake compensation driving parts440and450.

The position sensors443and453may be hall sensors. The position sensors443and453may sense the position of the lens barrel200through the magnets441and451of the first and second shake compensation driving parts440and450.

Meanwhile, a yoke part380maintains a state of contact between the shake compensation unit400and the plurality of ball members.

The yoke part380is attached to the carrier310so as to face the magnets441and451of the first and second shake compensation driving parts440and450in the optical axis direction (the Z-axis direction).

Therefore, an attractive force may be generated between the yoke part380and the magnets441and451in the optical axis direction (the Z-axis direction).

Because the shake compensation unit400is pressed in a direction toward the yoke part380by the attractive force between the yoke part380and the magnets441and451, the frame410and the lens holder420of the shake compensation unit400maintains a state of contact with the plurality of ball members.

For example, the lens holder420is pressed toward the frame410by the attractive force between the yoke part380and the magnets441and451, and thus, the frame410is pressed toward the carrier310.

In this example, the yoke part380includes first and second yoke parts380aand380b. The yoke part380may be formed of a material capable of generating attractive force between the yoke part380and the magnets441and451. For example, the yoke part380may be formed of a magnetic material.

The first yoke part380afaces the magnet441of the first shake compensation driving part440in the optical axis direction (the Z-axis direction), and the second yoke part380bfaces the magnet451of the second shake compensation driving part450in the optical axis direction (the Z-axis direction).

The lengths of the first and second yoke parts380aand380bin the directions perpendicular to the optical axis (the Z-axis) may be equal to or shorter than those of the magnets441and451in the directions perpendicular to the optical axis (the Z-axis). In this case, in response to the magnets441and451being moved in directions perpendicular to the optical axis (the Z-axis), a restoring force to return to the original positions may be further increased by the attractive force between the magnets441and451and the yoke part380.

To compensate for the shaking of the camera module1000, there is a need to instantly correspond to an unstable movement of the camera module generated due to a user's hand movement or the like. That is, the lens barrel200may have to be continuously moved in the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction).

For example, because the shaking of the camera module occurs rapidly at a rate of several tens of Hz per second, it may be difficult to generate vibrations that correspond to the shaking of the camera module using only electromagnetic force between the magnets441and451and the coils442and452.

Therefore, the lens barrel200may be moved in the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction) by simultaneously using the restoring force acting between the magnets441and451and the yoke part380and the electromagnetic force between the magnets441and451and the coils442and452.

Therefore, the position of the lens barrel200may be continuously adjusted, corresponding to the shaking, which may be further decrease power consumption.

When the camera module is turned on, the initial position (position in the directions perpendicular to the optical axis (the Z-axis)) of the lens barrel200may be sensed by the position sensors443and453. In addition, the lens barrel200may be moved from the sensed initial position to a setting position.

The setting position may be the center of a movable range in the first axis direction (the X-axis direction) and the center of a movable range in the second axis direction (the Y-axis direction). Mechanically, the setting position may be the center of the carrier310in which the shake compensation unit400is accommodated in the first axis direction (the X-axis direction) and in the second axis direction (the Y-axis direction).

When the camera module is not shaken, there is a need to fix the lens barrel200so as not to be moved in the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction).

According to this example, because the yoke part380attracts the magnets441and451in the optical axis direction (the Z-axis direction), when a shake compensation signal is not applied, the lens barrel200may be maintained in a state in which the lens barrel200is fixed in a predetermined position in the directions perpendicular to the optical axis (the Z-axis) by the attractive force between the yoke part380and the magnets441and451.

However, because each of the components of the camera module is accompanied with a manufacturing tolerance, in a case of only fixing the lens barrel200with the attractive force between the yoke part380and the magnets441and451, there is a risk that the optical axis (the Z-axis) of the lens may be misaligned with the center of the image sensor610, which may deteriorate image quality.

In addition, it may be difficult to maintain the lens barrel200to be in a fixed state only by the attractive force between the yoke part380and the magnets441and451.

Therefore, when the camera module is turned on, the position of the lens barrel200(in the directions perpendicular to the optical axis (the Z-axis)) may be adjusted so that the lens barrel200is mechanically positioned at the center in the directions perpendicular to the optical axis (the Z-axis).

Therefore, when the camera module is not shaking while the camera module is turned on, the lens barrel200may be maintained in a state in which the lens barrel200is mechanically fixed to the center in the directions perpendicular to the optical axis (the Z-axis) by the attractive force between the yoke part380and the magnets441and451and the driving force of the first and second shake compensation driving parts440and450.

Meanwhile, while the camera module is turned off, the position of the lens barrel200may be fixed by the attractive force between the yoke part380and the magnets441and451.

In this example, the yoke part380is provided so that the frame410and the lens holder420may maintain the state of contact with the plurality of ball members. In addition, as illustrated inFIG.2, a stopper210is provided to prevent the plurality of ball members, the frame410, and the lens holder420from being separated to the outside of the carrier310by external impacts or the like.

The stopper210is coupled to the carrier310to at least partially cover an upper surface of the lens holder420.

Meanwhile, when an optical image stabilization function is provided in a camera, because guide members guiding a lens barrel are additionally provided in a carrier310of a camera module, the sizes of the lens driving apparatus and the camera module tend to increase in comparison to cases in which the optical image stabilization function is not provided in a camera module.

For instance, in general, because a frame and the lens holder are sequentially disposed in the carrier in the optical axis direction (the Z-axis direction), the size of the lens driving apparatus500and the thickness of the camera module1000are increased in comparison to cases in which a frame and a lens holder are not provided.

However, according to the example illustrated inFIG.2, the lens driving apparatus500and the camera module1000are configured to provide the compensation function for the shaking of camera module without increasing the sizes of the lens driving apparatus500and the camera module1000.

The plan view shapes of the frame410and the lens holder420may be different from each other. The positions of the centers of gravity of the frame410and the lens holder420may be also different from each other.

For example, the plan view shape of the frame410may be a substantially ‘’ shape or an L-bracket shape, and the plan view shape of the lens holder420may be a substantially ‘’ shape or a rectangular shape with an opening in the center.

Therefore, a region in which the frame410is positioned and a region in which the frame410is not positioned may exist in a region in the optical axis direction (the Z-axis direction) between the carrier310and the lens holder420.

For example, when viewed in the optical axis direction (the Z-axis direction), there are a region in which the frame410and the lens holder420overlap each other and a region in which the frame410and the lens holder420do not overlap each other.

The region in which the frame410and the lens holder420overlap each other in the optical axis direction (the Z-axis direction) is a region in which the frame410is positioned between the carrier310and the lens holder420.

The region in which the frame410and the lens holder420do not overlap each other in the optical axis direction (the Z-axis direction) is a region in which the frame410is not positioned between the carrier310and the lens holder420. Therefore, the carrier310and the lens holder420directly face each other in the optical axis direction (the Z-axis direction) in this region.

The magnets441and451of the first and second shake compensation driving parts440and450and the yoke part380are disposed in the region in which the carrier310and the lens holder420directly face each other in the optical axis direction (the Z-axis direction).

That is, the frame410has an opening in a region in which the magnets441and451of the first and second shake compensation driving parts440and450and the yoke part380face each other in the optical axis direction (the Z-axis direction).

Therefore, the frame410is not positioned between the magnets441and451of the first and second shake compensation driving parts440and450and the yoke part380in the optical axis direction (the Z-axis direction), and thus, the magnets441and451are positioned close to the yoke part380.

According to this example, the region in which the frame410is not positioned between the carrier310and the lens holder420is obtained by allowing the frame410and the lens holder420to have different plan view shapes from each other, and the magnets441and451are positioned closer to the yoke part380by disposing the magnets441and451and the yoke part380in this region.

Therefore, the lens driving apparatus500and camera module1000may provide a shake compensation function without increasing the sizes or heights of the lens driving apparatus500and camera module1000in the optical axis direction (the Z-axis directions).

In this example, the mounting surfaces of the lens holder420on which the magnets441and451are mounted may further protrude toward a bottom surface of the carrier310as compared to the other portions of the lens holder420.

Meanwhile, the third ball member900is disposed between the carrier310and the lens holder420to support the lens holder420.

Because the magnets441and451of the first and second shake compensation driving parts440and450are mounted on one surface and another surface of the lens holder420to be orthogonal to each other, and the attractive force may act between the magnets441and451and the yoke part380, a pressing force biased toward the yoke part380may be applied to the lens holder420.

In this case, since the frame410is not disposed in the region in which the attractive force acts between the magnets441and451and the yoke part380, the lens holder420may be inclined by the attractive force between the magnets441and451and the yoke part380.

However, according to the example illustrated inFIG.2, the third ball member900is disposed between the carrier310and the lens holder420to prevent the lens holder420from being inclined.

Because the third ball member900directly supports the lens holder420between the carrier310and the lens holder420, the third ball member900may guide movement of the lens holder420in both the first axis direction (the X-axis direction) and the second axis direction (the Y-axis direction).

As described above, the frame410is not disposed in the region in which the attractive force acts between the magnets441and451and the yoke part380, but the lens holder420is supported by the third ball member900by disposing the third ball member900in the region in which the frame410is not disposed. Thus, the lens driving apparatus500and camera module1000provide a shake compensation function without increasing the sizes (heights) of the lens driving apparatus500and camera module1000in the optical axis direction (the Z-axis directions).

Because the biased pressing force is applied to the lens holder420, levels of strength of the pressing force applied to the second and third ball members800and900supporting the lens holder420may be different from each other.

For example, because the pressing force applied to the lens holder420is largest in the region in which the magnets441and451and the yoke part380face each other, the intensity of the pressing force applied to the third ball member900may be greater than that of the pressing force applied to the second ball member800.

Further, the intensity of the pressing force applied to the third ball member900may also be greater than that of the pressing force applied to the first ball member700.

As described above, the cross-sectional shape of the guide grooves disposed farthest away from the third guide grooves910and920accommodating the third ball member900to which the maximum pressing force is applied may differ from that of the guide grooves disposed to be closer to the third grooves910and920.

Meanwhile, as shown inFIG.1, because the sizes of the lens driving apparatus500and the camera module1000according to the present example are decreased, the lens barrel200may partially protrude outside the case110.

FIG.2illustrates that, even when the lens barrel200is positioned at its lowermost position in the housing120along the optical axis direction (the Z-axis direction), the lens barrel200partially protrudes outside the case110.

As set forth above, the lens driving apparatus and the camera module including the same may be miniaturized while providing the shake compensation function.

While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.