Lens drive device and camera module comprising same

A lens drive device includes a housing; a bobbin arranged inside the housing; a magnet arranged on the bobbin; a coil arranged on the housing and facing the magnet; a coupling member arranged on the inner surface of the housing; a roller rotatably arranged on the coupling member; and a rail arranged on the bobbin. The rail is guided according to the rotation of the roller.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Phase of PCT International Application No. PCT/KR2019/004282, filed on Apr. 10, 2019, which claims priority under 35 U.S.C. 119(a) to Patent Application No. 10-2018-0041567, filed in the Republic of Korea on Apr. 10, 2018, all of which are hereby expressly incorporated by reference into the present application.

TECHNICAL FIELD

The present invention relates to a lens driving device and a camera module comprising the same.

BACKGROUND ART

The content described below provides background information for this embodiment, but does not describe the prior art.

As the spread of various mobile terminals is widely generalized and wireless Internet services are commercialized, the demands of consumers related to the mobile terminals are also diversified, and various types of additional devices are mounted on the mobile terminals.

A representative one is a camera module that photographs a subject as a photo or video. Meanwhile, an auto focus function is being applied to a recent camera module to automatically adjust focus according to a distance of a subject.

The auto focus function is generally performed by moving the bobbin in which the lens is disposed, and the conventional lens driving device supports the bobbin through a spring. However, when supporting the movement of the bobbin through the spring as in the prior art, there is a problem that the movable distance of the bobbin is limited within the elastic range of the spring.

DETAILED DESCRIPTION OF THE INVENTION

Technical Subject

The problem to be solved by the present invention is to provide a lens driving device and a camera module comprising the same, which can be used not only for the auto focus function but also for the zoom function because the moving distance of the bobbin is increased.

Technical Solution

For solving the above problem, a lens driving device according to one aspect of the present invention comprises: a housing; a bobbin disposed inside the housing; a magnet disposed on the bobbin; a coil disposed on the housing and facing the magnet; a coupling member disposed on the inner surface of the housing; a roller rotatably disposed on the coupling member; and a rail disposed on the bobbin, wherein the rail is guided according to the rotation of the roller.

Also, the roller comprises at least two rollers, the at least two rollers are spaced apart from each other in the horizontal direction, the coil is disposed between the at least two rollers; the rail comprises at least two rails; the at least two rails are spaced apart from each other in the horizontal direction; and the magnet may be disposed between the at least two rails.

Also, the bobbin comprises a first groove formed by being extended in an optical axis direction on an outer lateral surface, and the rail may be disposed in the first groove.

Also, the rail may be formed by being extended in the optical axis direction.

Also, the rail is formed to be protruded toward the housing, and the cross-section of the rail may be a semi-circular shape.

Also, the rollers may comprise a plurality of rollers spaced apart from one another in the optical axis direction.

Also, the roller may have a shape in which the diameter decreases as it travels from both ends toward the central portion.

Also, the roller and the rail may contact at two contact points.

Also, the two contact points may be positions symmetrical to each other with respect to the central portion of the roller.

Also, the roller may comprise a protruding portion shaped by being extended from both ends.

Also, the coupling member comprises a flat plate disposed on the inner lateral surface of the housing, and a plurality of vertical plates being extended and formed from the flat plate toward the bobbin, and the plurality of vertical plates may be spaced apart from one another, and may comprise a first hole being penetrated by the protruding portion.

Also, the bobbin comprises first to fourth surfaces formed on the outer surface; the magnet comprises a first magnet disposed on the first surface and a second magnet disposed on the third surface, wherein the first magnet and the second magnet are symmetrical to each other with respect to the optical axis; the housing comprises fifth to eighth surfaces formed on an inner lateral surface so as to face each of the first to fourth surfaces; the coil comprises a first coil disposed on the fifth surface and a second coil disposed on the seventh surface, wherein the first coil and the second coil are symmetrical with respect to the optical axis; the coupling member comprises a first coupling member disposed on the fifth surface, and a second coupling member disposed on the seventh surface, wherein the first coupling member and the second coupling member are symmetrical to each other with respect to the optical axis; and the roller comprises a first roller disposed in the first coupling member, a second roller disposed in the second coupling member; the rail comprises a first rail disposed on the first surface and a second rail disposed on the third surface, wherein the first rail and the second rail may be symmetrical with respect to the optical axis.

Also, the bobbin comprises first to fourth surfaces formed on an outer lateral surface; the magnet comprises a first magnet disposed on the first surface, a second magnet disposed on the third surface, wherein the first magnet and the second magnet is symmetric to each other with respect to the optical axis; the housing comprises fifth to eighth surfaces formed on an inner lateral surface so as to face each of the first to fourth surfaces; the coil comprise a first coil disposed on the fifth surface, and a second coil disposed on the seventh surface, wherein the first coil and the second coil are symmetrical to each other with respect to the optical axis; the coupling member comprises a first coupling member disposed on the sixth surface and a second coupling member disposed on the eighth surface, wherein the first coupling member and the second coupling member are symmetrical to each other with respect to the optical axis; the roller comprises a first roller disposed in the first coupling member, a second roller disposed in the second coupling member; and the rail comprises a first rail disposed on the second surface and a second rail disposed on the fourth surface, wherein the first rail and the second rail may be symmetrical to each other with respect to the optical axis.

For solving the above problem, a lens driving device according to another aspect of the present invention comprises: a housing; a bobbin comprising a second groove formed on an outer lateral surface and disposed in the housing; a magnet disposed in the bobbin; a coil disposed in the housing and facing the magnet; a roller rotatably disposed in the second groove; and a first rail disposed on the inner lateral surface of the housing, wherein the roller can be guided and rotated along the first rail.

Also, the roller may comprise protruding portions shaped by being extended at both ends.

Also, the bobbin comprises a second hole formed on an inner lateral surface facing each other of the second groove, and the second hole can be penetrated by the protruding portion.

Also, the bobbin comprises a third groove formed on an inner lateral surface facing each other of the second groove, and both ends of the roller may be disposed in the third groove.

Also, the area of the roller disposed in the third groove decreases in diameter as it travels toward the both ends, and the area of the roller disposed between inner lateral surfaces facing each other of the second groove may decrease in diameter as it travels toward the central portion.

Also, the diameter of the central portion of the roller may be formed to be smaller than the diameter of both ends of the roller.

Further, a second rail disposed in the second groove is further included, and the second rail and the roller may be in contact with each other at two contact points.

For solving the above problem, a camera module according to one aspect of the present invention comprises: a housing; a bobbin disposed inside the housing; a lens module disposed on the bobbin; a magnet disposed on the bobbin; a coil disposed on the housing and facing the magnet; a coupling member disposed on the inner surface of the housing; a roller rotatably disposed on the coupling member; and a rail disposed on the bobbin, wherein the rail is guided according to the rotation of the roller.

Advantageous Effects

Through the present embodiment, the moving distance of the bobbin is increased, and thereby a lens driving device and a camera module comprising the same that can be used for a zoom function as well as an auto focus function can be provided.

BEST MODE

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. Advantages and features of the present invention, and methods for achieving them will be apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and the present embodiments are merely provided to complete the disclosure of the present invention and to fully inform the scope of the invention to those skilled in the art to which the present invention belongs, and the present invention will be merely defined by the scope of the claims. Like refer to like elements throughout. Throughout the specification, the same reference numeral refers to the same component.

Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used in a meaning that can be commonly understood by those skilled in the art to which the present invention belongs. In addition, terms that are defined in commonly used dictionaries are not ideally or excessively interpreted unless they are specifically defined clearly.

In addition, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention. In this specification, the singular may also include the plural unless specifically stated in the text. As used in this specification, ‘comprises’ and/or ‘comprising’ means not to exclude the presence or addition of one or more other components, steps, and/or operations in addition to the components, steps, and/or operations mentioned. And “and/or” includes each and all combinations of one or more of the items mentioned.

In addition, in describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are merely intended to distinguish the components from other components, and the terms do not limit the nature, order or sequence of the components. When a component is described as being ‘connected’, ‘coupled’ or ‘jointed’ to another component, the component may be directly connected, coupled or jointed to the another component, but it should be also understood that yet another component may be ‘connected’, ‘coupled’ or ‘jointed’ between the component and the another component.

‘Optical axis direction’ used below is defined as the optical axis direction of the lens coupled to the lens driving device. Meanwhile, the ‘optical axis direction’ may correspond to the ‘up and down’ direction and the ‘z axis direction.

The “auto focus function” used below is defined as the function that automatically focuses on a subject by moving the lens in the direction of the optical axis according to the distance of the subject so that clear images of the subject can be obtained on the image sensor. Meanwhile, ‘auto focus’ can be used interchangeably with ‘Auto Focus (AF)’.

Hereinafter, the configuration of an optical apparatus according to the present embodiment will be described.

The optical apparatus may be any one of a mobile phone, a mobile phone, a smart phone, a portable smart device, a digital camera, a laptop computer, a digital broadcasting terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), and a navigation device. However, the type of the optical apparatus is not limited thereto, and any device for capturing an image or a picture may be included in the optical apparatus.

The optical apparatus may comprise a main body. The main body may form the appearance of the optical apparatus. The main body may accommodate a camera module. A display unit may be disposed on one surface of the main body. For example, the display unit and the camera module may be disposed on one surface of the main body, and another camera module may be additionally disposed on the other surface (a surface opposite to the one surface) of the main body.

The optical apparatus may comprise a display unit. The display unit may be disposed on one surface of the main body. The display unit may output an image photographed by the camera module.

The optical apparatus may comprise a camera module. The camera module may be disposed in the main body. At least a portion of the camera module may be accommodated in the main body. The camera module may be provided in plurality. The camera module may be disposed respectively on one surface of the main body and the other surface of the main body. The camera module may photograph an image of a subject.

Hereinafter, the configuration of a camera module according to the present embodiment will be described with reference to the drawings.

The camera module may comprise a lens module12. The lens module12may comprise at least one lens. The lens module12may comprise a lens and a barrel. The lens module12may be coupled to a bobbin100of a lens driving device. The lens module12may be coupled to the bobbin100by screw-coupling and/or an adhesive. The lens module12may be moved integrally with the bobbin100.

The camera module may comprise a filter. The filter may comprise an infrared filter. The infrared filter may block the light of an infrared region from being incident on an image sensor. The infrared filter may be disposed between the lens module12and the image sensor. In one example, the infrared filter may be disposed in a sensor base disposed between the lens driving device10and a printed circuit board. In another example, the infrared filter can be placed in a hole in the base.

The camera module may comprise a printed circuit board. A lens driving device10may be disposed on the printed circuit board. At this time, a sensor base may be disposed between the printed circuit board and the lens driving device10. The printed circuit board may be electrically connected to the lens driving device10. An image sensor may be disposed on the printed circuit board. The printed circuit board can be electrically connected to the image sensor.

The camera module may comprise an image sensor. The image sensor can be disposed on a printed circuit board. The image sensor can be electrically connected to the printed circuit board. In one example, the image sensor may be coupled to a printed circuit board by a surface mounting technology (SMT). As another example, the image sensor may be coupled to a printed circuit board by a flip chip technology. The image sensor may be disposed such that the optical axis is coincided with the lens module12. That is, the optical axis of the image sensor and the optical axis of the lens module12may be aligned. The image sensor may convert light irradiated to the effective image area of the image sensor into an electrical signal. The image sensor may be any one of a charge coupled device (CCD), a metal oxide semi-conductor (MOS), a CPD, and a CID.

The camera module may comprise a control unit. The control unit may be disposed on the printed circuit board. The control unit may control the direction, intensity, and amplitude of the current supplied to a coil500of the lens driving device10. The control unit may perform an auto focus function by controlling the lens driving device10. Furthermore, the control unit may detect the position of the bobbin100through a Hall sensor to perform auto focus feedback control for the lens driving device10. In addition, the control unit may perform a zoom function by controlling the lens driving device10. The control unit may also perform feedback control for the zoom function through the Hall sensor.

Hereinafter, the present invention will be described in more detail according to the accompanying drawings.

FIG.1is a perspective view of a lens driving device according to an embodiment of the present invention;FIGS.2and3are exploded perspective views of a lens driving device according to an embodiment of the present invention;FIG.4is a perspective view of a coupling member of a lens driving device according to an embodiment of the present invention;FIG.5is a perspective view of a roller of a lens driving device according to an embodiment of the present invention;FIG.6is a bottom view of a lens driving device according to an embodiment of the present invention;FIG.7is a perspective view of a roller and a rail of a lens driving device according to an embodiment of the present invention; andFIG.8is a cross-sectional view of a roller and a rail of a lens driving device according to an embodiment of the present invention.

Referring toFIGS.1to8, a lens driving device10according to an embodiment of the present invention may comprise a bobbin100, a housing200, a cover can300, a magnet400, a coil500, a coupling member600, a roller700, and a rail800, however, other additional components are not excluded.

The lens driving device10may be a voice coil motor (VCM). The lens driving device10according to an embodiment of the present invention may move the bobbin100accommodating the lens module12by 0.5 mm or more in the optical axis C direction due to the electromagnetic force between at least one coil and the magnet. At this time, a roller700and a rail800structure may be applied to minimize the frictional force generated while the bobbin100moves. The rail800is attached to a moving part, and the roller700is attached to a fixed part so as to perform rolling motion in place. Or, as illustrated inFIG.12andFIG.16, as another modified embodiment, the rail800is attached to the housing200which is a fixed part, and the roller700is attached to the bobbin100which is a moving part to perform rolling motion. Since the roller700and the rail800are in contact with each other at two contact points C1and C2to guide the movement of the bobbin100, frictional force against the movement of the bobbin100can be reduced.

The lens driving device10may comprise a bobbin100. The bobbin100may be disposed on a plurality of side walls of the housing200. The bobbin100may be disposed on the base. The bobbin100may be disposed to be spaced apart from the housing200and/or the base at least in a portion thereof. The bobbin100may be moved along the inner surfaces220,230,240, and250of the side walls of the housing200. The bobbin100can be moved with respect to the base and an image sensor. The bobbin100may be moved in an optical axis C direction (vertical direction, z-axis direction, up-down direction) with respect to the image sensor. The bobbin100may be moved on the optical axis C of the lens module12and/or the image sensor.

In the present embodiment, the bobbin100may be moved to drive an autofocus function. Also, the bobbin100may be moved to drive a zoom function. The maximum movable range (stroke) of the bobbin100for the autofocus function may be 0.2 to 0.4 mm, and the maximum movable range (stroke) of the bobbin100for the zoom function may be 3 to 5 mm. In more detail, the maximum movable range (stroke) of the bobbin100for the autofocus function may be about 0.3 mm, and the maximum movable range of the bobbin100for the zoom function may be about 4 mm. Here, the ‘maximum movable range (stroke)’ may be a distance difference between the position of the bobbin100in a state where the bobbin100is moved upward as far as possible and the position of the bobbin100in a state where the bobbin100is moved downward as far as possible.

The bobbin100may comprise a through hole110. The through hole110may penetrate the central portion of the bobbin100in the vertical direction. The lens module12may be coupled to the through hole110. A thread may be formed on the inner circumferential surface of the bobbin100that forms the through hole110. In this case, the lens module12and the bobbin100may be screw-coupled. The bobbin100may be formed through injection.

The bobbin100may comprise a plurality of lateral surfaces. The plurality of lateral surfaces may comprise first to fourth surfaces130,140,150, and160. The bobbin100may comprise a first surface130and a third surface150disposed opposite each other, and a second surface140and a fourth surface160disposed opposite each other between the first surface130and the second surface150.

The bobbin100may comprise a groove120. The groove120may be a ‘rail groove’ in which a rail800is disposed. Also, the groove120may be referred to as a ‘first groove’ and the like to distinguish it from other grooves. The groove120may be formed on a lateral surface of the bobbin100. The rail800may be disposed in the groove120. The groove120may be extended from the lateral surface of the bobbin100in the optical axis C direction or in the vertical direction. The width of the groove120may be extended from the lower end to the upper end of the bobbin100. Or, the vertical length of the groove120may correspond to the vertical length of the rail800. Through this, the moving distance of the bobbin100can be maximized. The width of the groove120(horizontal length) may be greater than the width of the rail800. Through this, the number of points in contact between the roller700and the rail800can be reduced to minimize the frictional force.

The groove120may comprise a plurality of grooves122and124formed on one surface of the bobbin100. The plurality of grooves122and124may be formed with a width corresponding to each other and a length corresponding to each other (vertical length). A magnet400may be disposed between the plurality of grooves122and124. The plurality of grooves122and124may be formed at positions symmetrical to each other centered around the magnet400. Through this, the bobbin100can be guided stably.

The lens driving device10may comprise a housing200. A printed circuit board may be disposed under the housing200. The housing200may be disposed outside the bobbin100. The housing200may accommodate the bobbin100therein. The housing200may comprise an accommodation space therein. The bobbin100may be disposed in the accommodation space of the housing200. The housing200may be spaced apart from the bobbin100at least in a portion thereof. The housing200may be formed through injection.

The upper surface of the housing200may comprise an opening210being overlapped with the upper surface of the lens module12. At least a portion of the lens module12may penetrate the opening210. The upper portion of the lens module12may be disposed on the same plane as the opening210.

The housing200may comprise a side wall. The side wall forms an accommodation space therein, and the bobbin100may be disposed in the accommodation space formed by the side wall. The side wall may comprise a plurality of side walls. The plurality of side walls may comprise fifth to eighth surfaces220,230,240, and250formed on the inner lateral surface. The plurality of side walls of the housing200may comprise a fifth face220facing the first surface130of the bobbin100, a sixth surface230facing the second surface140of the bobbin100, a seventh surface240facing the third surface150of the bobbin100, and an eighth surface250facing the fourth surface160of the bobbin100.

The lens driving device10may comprise a cover can300. The cover can300may be coupled with the base500. The cover can300can accommodate the housing100therein. The cover can300may form an external appearance of the lens driving device. The cover can300may be in the shape of a cuboid with a lower surface open. The cover can300may be non-magnetic. The cover can300may be formed of a metal material. The cover can300may be formed of a metal sheet material. The cover can300may be connected to the ground portion of the printed circuit board10. Through this, the cover can300may be grounded. The cover can300may block the electromagnetic interference (EMI).

The cover can300may comprise an upper plate310and a side plate320. The cover can300may comprise an upper plate310comprising holes and a plurality of side plates320being extended downward from an outer periphery or edge of the upper plate310. The lower end of the side plate320may be disposed on a portion of the base. The inner surface of the side plate320may be coupled with the base by an adhesive.

The upper plate310of the cover can300may comprise a through hole312. The through hole312may be formed on the upper plate310of the cover can300. The through hole312may expose at least a portion of the lens module12upward (outside). The through hole312may be formed in a size and shape corresponding to the lens module12. The size of the through hole312may be formed larger than the diameter of the lens module12so that the lens module12can be inserted and assembled through the through hole312. The through hole312of the cover can300may be formed in a shape corresponding to an opening210of the upper surface of the housing200. The through hole312of the cover can300may be overlapped with the opening210of the upper surface of the housing200. A light introduced through the through hole312may pass through the lens module12. At this time, the light passing through the lens module12may be converted into an electrical signal from the image sensor and obtained as an image.

The lens driving device10may comprise a magnet400. The magnet400may be disposed in the bobbin100. The magnet400may face the coil500. When an electric current is applied to the coil500, an attractive force or a repulsive force may act between the magnet400and the coil500by electromagnetic interaction. Through this, the bobbin100and the lens module12moving integrally with the magnet400may be moved. That is, the magnet400may provide a driving force to the bobbin100through the electromagnetic interaction with the coil500.

The lens driving device10may comprise a coil500. The coil500may be disposed inside the housing200. The coil500may face the magnet400. The coil500may be attached to a coupling member600attached to the inner lateral surface of the housing200. One surface of the coil500is attached to a flat plate610of the coupling member600and the other surface of the coil500may face one surface of the magnet400. The coil500may be spaced apart from the magnet400. The coil500may be electrically connected to a substrate. The coil500may be connected to a printed circuit board through the substrate to receive a current.

The lens driving device10may comprise a coupling member600. The coupling member600may be disposed on the inner lateral surface of the housing200. The coupling member600may be integrally formed with the housing200. Alternatively, the coupling member600may be manufactured separately from the housing200and then attached to the inner lateral surface of the housing200.

The coupling member600may comprise a flat plate610attached to the inner lateral surface of the housing200. One surface of the flat plate610may be attached to the inner lateral surface of the housing200, and the coil500may be attached to the other surface of the flat plate610. The flat plate610may be formed in the shape of a rectangular plate, but is not limited thereto and may be variously changed.

The coupling member600may comprise a vertical plate620formed by being extended from the flat plate610toward the bobbin100. The vertical plate620may be formed by being extended in the optical axis C direction or vertical direction. The height of the vertical plate620may be the same as the height of the groove120of the bobbin100. At least a portion of the vertical plate620may be disposed in the groove120of the bobbin100. Through this, space efficiency can be improved. At least a portion of the vertical plate620may be disposed spaced apart from the inner lateral surface of the groove120of the bobbin100.

The vertical plate620may comprise a plurality of vertical plates. The plurality of vertical plates may comprise first to fourth vertical plates622,624,626, and628. The first to fourth vertical plates622,624,626, and628may be formed spaced apart from each other. Rollers700may be disposed in a space among the plurality of vertical plates. The rollers700may be disposed in the spaces between the first vertical plate622and the second vertical plate624, between the third vertical plate626and the fourth vertical plate628, and between622,624,626, and628. The coil500may be disposed in a space between the plurality of vertical plates. The coil500may be attached to the flat plate610between the second vertical plate624and the third vertical plate626.

The vertical plate620may comprise a hole. The hole of the vertical plate620may be a ‘roller hole’ penetrated by a protruding portion708of the roller700. Also, a hole may be referred to as a ‘first hole’ to distinguish it from other holes. The diameter of the hole of the vertical plate620may correspond to the diameter of the protruding portion708of the roller700.

The hole may comprise a plurality of holes6222,6224,6242,6244,6262,6264,6282, and6284. Each of the first to fourth vertical plates622,624,626, and628may comprise two holes6222,6224,6242,6244,6262,6264,6282, and6284, respectively. Two rollers712and714are mounted in the holes6222,6224,6242, and6244formed in the first and second vertical plates622and624, and two rollers716and718may be mounted in the holes6262,6264,6282, and6284formed in the third and fourth vertical plates626and628.

The lens driving device10may comprise a roller700. The roller700may be disposed in the coupling member600. The roller700may be rotatably coupled to the coupling member600. When the bobbin100is moved in the direction of the optical axis C, the roller700may be in contact with the rail800so as to be rotated in place. The roller700may be spaced apart from the flat plate610. At least a portion of the roller700may have a shape in which the diameter decreases from the both ends704and706toward the central portion702. The ratio of the decreasing diameter as it travels from the both ends704and706of the roller700toward the central portion702may be constant, may be gradually increased, or may be gradually decreased, but is not limited thereto and may be variously changed. Through this, it is possible to minimize the number of contact points in contact between the roller700and the rail800. The vertical length of the central portion702of the roller700may be smaller than the vertical length of both ends704and706of the roller700.

The roller700may comprise a protruding portion708. The protruding portion708may comprise a plurality of protruding portions. The plurality of protruding portions may comprise a first and a second protruding portion7042and7062. The first protruding portion7042may protrude from one end704of the roller700, and the second protruding portion7062may protrude from the other end706of the roller700. At this time, the first protruding portion7042and the second protruding portion7062may be formed to be symmetrical to each other with respect to the central portion702of the roller700. The diameter of the protruding portion708may be formed to be smaller than the diameter of both ends704and706of the roller700. The first protruding portion7042penetrates the holes6222and6224of the first vertical plate622or the holes6262and6264of the third vertical plate626, and the second protruding portion7062may penetrate the holes6242and6244of the second vertical plate624or the holes6282and6284of the fourth vertical plate628. Through this, the roller700can be rotatably disposed in the coupling member600without adding a separate component.

The roller700may be in contact with the rail800. The roller700may be rotated in place when the rail800is moved in the vertical direction. When the rail800is moved upward, the roller700is rotated in one direction, and when the rail800is moved downward, the roller700is rotated in the other direction. The up-down movement of the rail800may be guided by the rotation of the roller700. The horizontal length of the roller700may be smaller than the horizontal width of the rail800. The roller700may be in contact with the rail800at two contact points C1and C2. The two contact points C1and C2may be formed at positions symmetrical to each other with respect to the central portion702of the roller700. Through this, the up-down movement of the bobbin100can be guided stably.

The roller700may comprise a plurality of rollers. The plurality of rollers may comprise four rollers712,714,716, and718. At least two of the four rollers may be spaced apart in the horizontal direction, and at least two rollers may be disposed spaced apart in the vertical direction. The coil500may be disposed between at least two rollers disposed spaced apart in the horizontal direction.

The lens driving device10may comprise a rail800. The rail800may be disposed in the groove120of the bobbin100. The rail800may be formed to be extended in the direction of the optical axis C. The vertical length of the rail800may be corresponding to the vertical length of the groove120of the bobbin100or may be small. The width of the rail800(horizontal length) may be smaller than the width of the groove120of the bobbin100. The rail800may be seated in the groove120of the bobbin100. The rail800may be formed to be protruded toward the housing200. The rail800may be located further inside than the outer lateral surface of the bobbin100. At least a portion of the cross-section of the rail800may be in the shape of a semi-circle. Through this, the space efficiency can be enhanced, and the number of contact points in contact between the roller700and the rail800can be minimized.

The rail800can be in contact with the roller700. The movement of the rail800in the up-down direction can be guided by the rotation of the roller700in place. When the rail800is moved upward, the roller700is rotated in one direction to guide the upward movement of the rail800, and when the rail800is moved downward, the roller700is rotated in the other direction, and thereby it is possible to guide the downward movement of the rail800. The rail800may be in contact with the roller700at two contact points C1and C2. The two contact points C1and C2may be formed at positions symmetrical to each other with respect to the central portion702of the roller700. The horizontal width of the rail800may be formed to be smaller than the horizontal length of the roller700.

The rail800may comprise a plurality of rails. The plurality of rails may comprise two rails802and804. The two rails802and804may be spaced apart from each other in the horizontal direction. The two rails802and804may be formed in shapes and sizes corresponding to each other. A magnet400may be disposed between the two rails802and804. The two rails802and804may be symmetrical to each other with respect to the magnet400. Through this, it is possible to stably guide the movement of the bobbin100.

FIGS.9to11are bottom views of a modified embodiment of the lens driving device according to an embodiment of the present invention, andFIG.12is a perspective view of a modified embodiment of the coupling member of the lens driving device according to an embodiment of the present invention.

Referring toFIG.9, a first magnet410may be disposed on a first surface130of the bobbin100, and a second magnet420may be disposed on a third surface150of the bobbin100. The first magnet410and the second magnet420may be formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. A first coil510may be disposed on a fifth surface220of the housing200, and a second coil520may be disposed on a seventh surface240of the housing200. The first coil510and the second coil520may be formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. The first magnet410and the first coil510may face each other, and the second magnet420and the second coil520may face each other. A first coupling member630may be disposed on a fifth surface220of the housing200, and a second coupling member640may be disposed on a seventh surface240of the housing200. The first coupling member630and the second coupling member640may be formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. In a modified embodiment, the first and second coupling members630and640may be formed of a flat plate610and a first and a second vertical plate622and624, respectively. A first roller720may be disposed in the first coupling member630, and a second roller730may be disposed in the second coupling member640. The first roller720and the second roller730are formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. One rail800is disposed in the groove120formed in the first surface130of the bobbin100, and one may be disposed in the groove120formed in the third surface130of the bobbin100. The rail disposed in the groove120formed in the first surface130and the rail disposed in the groove120formed in the third surface130are formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in a shape corresponding to each other.

Referring toFIG.10, the first magnet410may be disposed on the first surface130of the bobbin100, and the second magnet420may be disposed on the third surface150of the bobbin100. The first magnet410and the second magnet420may be formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. The first coil510may be disposed on the fifth surface220of the housing200, and the second coil520may be disposed on the seventh surface240of the housing200. The first coil510and the second coil520may be formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. The first magnet410and the first coil510may face each other, and the second magnet410and the second coil520may face each other. The first coupling member630may be disposed on a sixth surface230of the housing200, and the second coupling member640may be disposed on an eighth surface250of the housing200. The first coupling member630and the second coupling member640may be formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. In the modified embodiment, the first and the second coupling member630and640may be formed of flat plates610and the first and second vertical plates622and624, respectively. The first roller720may be disposed in the first coupling member630, and the second roller730may be disposed in the second coupling member640. The first roller720and the second roller730are formed at positions symmetrical to each other with respect to the optical axis C, and may be formed in shapes corresponding to each other. One rail800is disposed in the groove120formed in the second surface140of the bobbin100, one may be disposed in the groove120formed in the fourth surface150of the bobbin100. The rail disposed in the grooves120formed in the second surface140and the rail disposed in the grooves120formed in the fourth surface150are formed at positions symmetrical to each other with respect to the optical axis C. It may be formed in a corresponding shape.

Referring toFIG.11, in the modified embodiment described inFIG.9, a third coupling member650, a fourth coupling member660, a third roller740, a fourth roller750, and two rails are added. The third coupling member650may be disposed on the fifth surface220of the housing200, and the fourth coupling member660may be disposed on the seventh surface240of the housing200. The third coupling member650and the fourth coupling member660are disposed at the positions symmetrical to each other with respect to the optical axis C, and may be formed in a corresponding shape. The first coupling member630and the third coupling member650may be formed at positions symmetrical to each other with respect to the first coil510and may be formed in shapes corresponding to each other. The second coupling member640and the fourth coupling member660may be formed at positions symmetrical to each other with respect to the second coil520and may be formed in shapes corresponding to each other. The third roller740may be disposed in the third coupling member650, and the fourth roller750may be disposed in the fourth coupling member660. The third roller740and the fourth roller750are disposed at the positions symmetrical to each other based on the optical axis C, and may be formed in shapes corresponding to each other. One rail800is disposed in the groove120formed in the first surface130of the bobbin100, and one is disposed in the groove120formed in the third surface130of the bobbin100, one is disposed in the groove120formed in the third surface130of the bobbin100, and may be formed in a shape corresponding to positions symmetrical to each other.

In one embodiment of the present invention, the groove120of the bobbin100may be formed on at least one of the first to fourth surfaces130,140,150, and160of the bobbin100, and the groove120of the bobbin100formed on at least one surface may comprise a plurality of grooves. The coupling member600, the roller700, and the rail800may be formed in a number corresponding to the groove120of the bobbin100and disposed at a corresponding position. If the magnet400and the coil500are formed in a number corresponding to each other and are disposed to face each other, the number of the magnet400and the coil500may be variously changed. For example, unlike the illustrated case, the first magnet410and the second magnet420may be disposed on the adjacent surfaces, and the first coil510and the second coil520may be disposed on the adjacent surfaces. Referring toFIGS.9to11, the coil500may be directly attached to the inner lateral surface of the housing200facing the magnet400. The coil500may be wound on a yoke. The coil500may be fixed to an inner surface of a side wall of the housing200by disposing an adhesive on at least one surface while being wound on a yoke.

As in the modified embodiment of an embodiment of the present invention, the bobbin100may be prevented from being overturned (flipped) through components symmetrical in different diagonal directions with respect to the optical axis C.

Referring toFIG.12, the plurality of rollers may comprise six rollers712,714,715,716,718, and719, and each of the first to fourth vertical plates622,624,626, and628may comprise two holes, respectively. That is, at least three of the plurality of rollers may be disposed in the vertical direction. In the present invention, the plurality of rollers disposed in the vertical direction will be described as an example of two and three, but is not limited thereto and may be variously changed according to the specifications of the product.

In the lens driving device10according to an embodiment of the present invention, when the bobbin100is moved in the up-down direction, the up-down movement of the bobbin100may be guided through the roller700and the rail800. At this time, frictional force can be minimized through two-point contact between the roller700and the rail800. In addition, since the rail800is disposed in the groove120formed in the bobbin100, the specification of the product can be minimized.

FIG.13is an exploded perspective view of a lens driving device according to another embodiment of the present invention;FIG.14is a perspective view of some components of a lens driving device according to another embodiment of the present invention; andFIGS.15and16are bottom views of a lens driving device according to another embodiment of the present invention.

Referring toFIGS.13to15, a lens driving device10according to another embodiment of the present invention comprises a bobbin100, a housing200, a cover can300, a magnet400, a coil500, a roller700, and a rail800, but other additional components are not excluded. The overlapped description of the same configuration as the camera module10according to an embodiment of the present invention will be omitted, and the same name and the same reference numerals will be assigned to the same components.

The bobbin100may comprise a groove170. The groove170may be a “roller groove” in which the roller700is disposed. Also, the groove170may be referred to as a ‘second groove’ and the like to distinguish it from other grooves. The groove170may be formed on the lateral surface of the bobbin100. A roller700may be disposed in the groove170. The groove170may be extended from the lateral surface of the bobbin100in the optical axis C direction or in the vertical direction. The width of the groove170(horizontal length) may be greater than the width of the roller700. The width of the groove170may be extended from the lower end to the upper end of the bobbin100.

The groove170may comprise a plurality of grooves172and174formed on one surface of the bobbin100. The plurality of grooves172and174may be formed with a width corresponding to each other and a length corresponding to each other (vertical length). A magnet400may be disposed between the plurality of grooves172and174. The plurality of grooves172and174may be formed at positions symmetrical to each other centered around the magnet400.

The bobbin100may comprise a plurality of holes1720and1740. In addition, to distinguish it from other holes, the plurality of holes1720and1740may be referred to as a ‘second hole’ and the like. The plurality of holes1720and1740may be disposed in the groove170of the bobbin100. The plurality of holes1720and1740may be formed on inner lateral surfaces facing each other among the grooves170of the bobbin100. At least a portion of the plurality of holes1720and1740may be penetrated by the protruding portion708of a roller700. For example, protruding portions of each of the four rollers712,714,716, and718may be inserted into a plurality of holes1722,1724,1726,1728,1742,1744,1746, and1748.

The housing200may comprise a coil groove on the inner lateral surface. The coil500may be disposed in the coil groove. The coil500is disposed in the coil groove, and at least a portion of the coil500may be protruded out of the coil groove.

The roller700may be rotatably disposed in the groove170of the bobbin100. The roller700may comprise a plurality of rollers712,714,716, and718. At least a portion of each protruding portion708of the plurality of rollers712,714,716, and718may be inserted into a plurality of holes1722,1724,1726,1728,1742,1744,1746, and1748formed in the groove170of the bobbin100.

The rail800may comprise a first rail810. The first rail810may be disposed on the inner lateral surface of the housing200. The first rail810may be integrally formed with the housing200. After the first rail810is manufactured separately, it may be attached to the inner lateral surface of the housing200. The first rail810can be in contact with the roller700. The first rail810may comprise a plurality of first rails812,814,816, and818.

In another embodiment of the present invention, the roller700is disposed in the bobbin100through the groove170formed in the bobbin100, and the first rail810is disposed in the housing200. When the bobbin100is moved in the up-down direction by the magnetic interaction between the magnet400and the coil500, the roller700installed on the bobbin100is rotated along the first rail810and performs rolling motion. At this time, the first rail810may guide the movement of the roller700.

Referring toFIG.16, the rail800may comprise a second rail820. The second rail820may be disposed in the groove170of the bobbin100. The second rail820may be disposed on the lower surface of the groove170of the bobbin100. The second rail820may have a shape corresponding to the first rail810. The second rail820may be in contact with the roller700. When the roller700on one side is rotated along the first rail810, the roller700on the other side is rotated in contact with the second rail820, and thus the position of the roller700may be guided so that the roller700does not escape. The second rail820may comprise a plurality of second rails822,824,826, and828.

The number and arrangement of grooves170, first and second magnets410and420, first and second coils510and520, rollers700, first and second rails810and820formed on the bobbin100of the lens driving device10according to another embodiment of the present invention may be variously changed like the lens driving device10according to an embodiment of the present invention.

FIG.17is an exploded perspective view of a lens driving device according to another embodiment of the present invention;FIG.18is a front view of some components of a lens driving device according to another embodiment of the present invention, andFIG.19is a cross-sectional view of some components of a lens driving device according to another embodiment of the present invention.

Referring toFIGS.17to19, a lens driving device10according to yet another embodiment of the present invention comprises a bobbin100, a housing200, a cover can300, a magnet400, a coil500, a roller700, and a rail800, but other additional components are not excluded. The overlapped description of the same configuration as the camera module10according to an embodiment of the present invention will be omitted, and the same name and the same reference numerals will be assigned to the same components.

The bobbin100may comprise grooves1760and1780. The grooves1760and1780may be ‘both end groove’ at which both ends704and706of the rail700are disposed. In addition, to distinguish it from other grooves, the grooves1760and1780may be referred to as a ‘third groove’ and the like. The third grooves1760and1780of the bobbin100may be formed on inner lateral surfaces facing each other of the second groove170of the bobbin100. The roller700may be disposed in the third grooves1760and1780of the bobbin100. Both ends704and706of the roller700may be disposed in the third grooves1760and1780of the bobbin100. The height of the third grooves1760and1780may be greater than the height of the roller700. The inner lateral surfaces of the third grooves1760and1780may be spaced apart from the roller700. Through this, the roller700may be rotatably disposed in the third grooves1760and1780. The third grooves1760and1780of the bobbin may comprise a plurality of third grooves1762,1764,1766,1768,1782,1784,1786, and1788, respectively.

The roller700may be disposed in third grooves1760and1780of the bobbin100. Both ends of the roller700may be disposed in third grooves1760and1780of the bobbin100. At least a portion of the area of the roller700disposed in the third grooves1760and1780of the bobbin100may decrease in diameter as it travels toward the ends704and706of the roller700. At least a portion of the area disposed between the inner lateral surfaces facing each other of the second groove170of the bobbin100among the rollers700may decrease in diameter as it travels toward the central portion702. The roller700may comprise reference lines705and707. The reference lines705and707may be located on the same plane as the second groove170where the third groove1760and1780are initiated. Among the cross-sections of the roller700, the cross-sections of the reference lines705and707may have the largest diameter. Each of the plurality of rollers712,714,716, and718may be disposed in a plurality of third grooves1762,1764,1766,1768,1782,1784,1786, and1788.

In embodiments of the present invention, although it has been described as an example that the magnet400is disposed in the bobbin100and the coil500is disposed in the housing200, the coil500may be disposed in the bobbin100, and the magnet400may be disposed in the housing200.

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention belongs may understand that the present invention can be implemented into other specific forms without changing the technical spirit or essential features thereof. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive.