KR102554388B1 - Camera module - Google Patents

Abstract

The camera module of the embodiment includes a bobbin on which at least one lens is mounted, a position detector detecting the position of the bobbin in the optical axis direction and outputting the position information as position information, and a first facing each other to move the bobbin in the optical axis direction of the lens. The auto focus function is performed by moving the bobbin by a first movement amount in a first direction parallel to the optical axis by controlling the interaction between the first coil and the driving magnet according to the coil and the driving magnet and given subject information and location information. It includes a focus control unit that does.

Description

Camera module {Camera module}

The embodiment relates to a camera module.

In recent years, the development of IT products such as mobile phones, smart phones, tablet PCs, and laptops with built-in digital cameras is actively progressing. Accordingly, a camera module having a digital camera is required to provide various functions such as auto focusing, shutter, shake reduction, or zoom function, while miniaturization and high resolution are trending.

On the other hand, in the case of the existing camera module, since the position of the subject cannot be known, a difference in resolution of the actuator may occur depending on the degree of hysteresis or repeatability. As such, the existing camera module may have a problem in that the time required for the auto focus function is long.

The embodiment provides a camera module capable of performing an autofocus function quickly and accurately.

Camera module according to the embodiment includes a bobbin equipped with at least one lens; a position detector detecting the position of the bobbin in the direction of the optical axis and outputting the position information as position information; a first coil and a driving magnet facing each other to move the bobbin in the direction of the optical axis of the lens; and controlling the interaction between the first coil and the driving magnet according to given subject information and the location information to move the bobbin by a first movement amount in a first direction parallel to the optical axis to perform an auto focus function. It may include a focus control unit that does.

The subject information may include at least one of a distance between the subject and the at least one lens, a position of the subject, or a phase of the subject.

The focus controller may include an information receiving unit receiving the subject information; a bobbin position search unit for finding a position of the bobbin that is in focus corresponding to the received subject information; and a movement amount adjusting unit that moves the bobbin by the first movement amount to the found position based on the location information.

The bobbin position search unit may include a look-up table for mapping and storing the position of the bobbin in focus corresponding to the subject information; and a data extraction unit extracting a position of the bobbin that is in focus corresponding to the received subject information from the look-up table.

The look-up table may code and store the position of the bobbin.

The look-up table may be generated using the position detector before moving the bobbin by the first movement amount.

The focus controller moves the bobbin within a range of a second movement amount smaller than the first movement amount after moving the bobbin by the first movement amount, and the final focus of the bobbin showing the largest value among frequency modulation transfer function values location can be found.

The focus controller may move the bobbin for a predetermined period or a predetermined number of times to find the largest value among the frequency modulation transfer function values.

The camera module further includes a second coil disposed to face the driving magnet, and the interaction between the second coil and the driving magnet causes the second and third directions orthogonal to the first direction. The bobbin may be movable.

The camera module may further include an image sensor outputting the subject information to the focus controller.

The camera module according to the embodiment may perform an auto focus function quickly and accurately.

1 shows a schematic perspective view of a lens driving device according to an exemplary embodiment.
FIG. 2 is a schematic exploded perspective view of the lens driving device illustrated in FIG. 1 according to an embodiment.
FIG. 3 is a schematic perspective view of a lens driving device from which the cover can is removed in FIG. 1 according to an embodiment.
4 shows a schematic plan perspective view of a housing member according to an embodiment.
5 shows a schematic bottom perspective view of a housing member according to an embodiment.
6 is a schematic exploded perspective view of a driving magnet, a housing member, a first circuit board, and a position sensing unit according to an exemplary embodiment.
7 shows a plan perspective view of an upper elastic member.
8 shows a plan perspective view of a lower elastic member.
9 shows a plan perspective view according to an embodiment of the bobbin shown in FIG.
FIG. 10 shows a bottom perspective view of the bobbin shown in FIG. 2 according to an embodiment.
11 is an exploded perspective view of a bobbin, a first coil, a position sensor, and a sensing magnet according to an embodiment.
12 is a schematic bottom perspective view of a bobbin, a first coil, first and second driving magnets, a position detector, and a sensing magnet according to an embodiment.
13 is a flowchart illustrating an auto focus function performed by a focus controller of a camera module according to an exemplary embodiment.
14 shows a block diagram of a focus controller according to an embodiment.
15 (a) and (b) are graphs for explaining an auto focus function according to a comparative example.
16 (a) and (b) are graphs for explaining an auto focus function according to an embodiment.
17 (a) and (b) are graphs for explaining fine adjustment in an auto focus function according to an embodiment.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the embodiment can be described so that those skilled in the art can easily implement it. In the accompanying drawings, it may be noted that the same reference numbers are used as much as possible when indicating the same configuration in other drawings. In addition, when it is determined that a detailed description of a related known function or known configuration in describing an embodiment may unnecessarily obscure the gist of the embodiment, the detailed description may be omitted. And certain features presented in the drawings are enlarged, reduced, or simplified for ease of explanation, and the drawings and their components are not necessarily drawn to scale. However, those skilled in the art will readily understand these details.

A camera module according to an embodiment may include a lens driving device 100 and a focus controller 300 . Here, the camera module may be applied to a mobile device such as a mobile phone.

Hereinafter, the lens driving device 100 of the camera module according to the embodiment will be described with reference to FIGS. 1 to 12 as follows. The embodiments illustrated in FIGS. 1 to 12 are described using an orthogonal coordinate system (x, y, z), but the embodiments are not limited thereto. That is, of course, the embodiment can be described using a different coordinate system. In each figure, the x-axis and the y-axis mean a plane perpendicular to the optical axis, and for convenience, the z-axis direction, which is the optical axis direction, can be referred to as the first direction, the x-axis direction as the second direction, and the y-axis direction as the third direction. .

1 shows a schematic perspective view of a lens driving device 100 according to an embodiment, FIG. 2 shows a schematic exploded perspective view of the lens driving device 100 according to an embodiment illustrated in FIG. 1, and FIG. 1 shows a schematic perspective view of the lens driving device 100 from which the cover can 102 is removed according to an embodiment.

The lens driving device 100 according to the embodiment is controlled by a focus controller 300 to be described later, and a distance between a lens (not shown) and an image sensor (not shown) is adjusted so that the image sensor is positioned at the focal length of the lens. can be made That is, the focus controller 300 may perform an 'auto focus function' for automatically focusing the lens in the lens driving device 100 .

1 to 3, the lens driving device 100 according to the embodiment includes a cover can 102, a bobbin 110, a first coil 120, a driving magnet 130, and a housing member. 140, an upper elastic member 150, a lower elastic member 160, a first circuit board 170, a position sensor 180, a magnet for sensing 182, and a base 190. .

The cover can 102 may have a box shape as a whole, and may be configured to be mounted, seated, contacted, fixed, temporarily fixed, supported, coupled, or placed on top of the base 190 . The bobbin 110, the first coil 120, and the driving magnet 130 in the accommodation space formed by mounting, seating, contacting, fixing, temporarily fixing, supporting, combining, or placing the cover can 102 on the base 190. ), the housing member 140, the upper elastic member 150, the lower elastic member 160, the first circuit board 170, the position detector 180, and the sensing magnet 182 may be accommodated.

The cover can 102 may include an opening 101 on an upper surface through which a lens (not shown) coupled to the bobbin 110 may be exposed to external light. Further, additionally, a window made of a light-transmitting material may be provided in the opening 101, and thus foreign substances such as dust or moisture may be prevented from penetrating into the camera module.

The cover can 102 may include a first groove portion 104 formed at a lower portion, and the base 190 may include a second groove portion 192 formed at an upper portion. At this time, as will be described later, when the cover can 102 is mounted, seated, contacted, fixed, temporarily fixed, supported, coupled, or disposed on the base 190, the portion that comes into contact with the first groove 104 (i.e., A second groove 192 may be formed at a position corresponding to the first groove 104 . A concave portion of a certain area may be formed through contact, arrangement, or coupling between the first groove portion 104 and the second groove portion 192 . An adhesive member having viscosity, for example, epoxy may be injected and applied to the groove. That is, the adhesive member applied to the concave portion fills the gap between the surfaces of the cover can 102 and the base 190 facing each other through the concave portion, so that the cover can 102 is mounted on the base 190 , It is possible to seal between the cover can 102 and the base 190 while seated, contacted, fixed, temporarily fixed, supported, coupled, or placed, and the cover can 102 is mounted on the base 190, The sides may be closed or coupled while being seated, contacted, secured, temporarily secured, supported, coupled, or positioned.

In addition, the cover can 102 may further include a third groove 106 . Here, the third groove 106 is formed on a surface corresponding to the terminal surface of the first circuit board 170, and can prevent the plurality of terminals 171 formed on the terminal surface and the cover can 102 from interfering with each other. there is. The third groove portion 106 may be concavely formed on the entire surface of the first circuit board 170 facing the terminal surface, and an adhesive member is applied to the inside of the third groove portion 106 so that the cover can 102 and the The base 190 and the first circuit board 170 may be sealed or coupled.

The first groove 104 and the third groove 106 may be formed in the cover can 102, and the second groove 192 may be formed in the base 190, but the embodiment is not limited thereto. That is, according to another embodiment, the first to third grooves 104 , 192 , and 106 may be formed only on the base 190 or only on the cover can 102 .

In addition, the material of the aforementioned cover can 102 may include metal, but the embodiment is not limited to the material of the cover can 102 . In addition, the cover can 102 may be formed of a magnetic material.

The base 190 may be provided in a rectangular shape as a whole, and may include a stepped portion protruding outward by a predetermined thickness so as to surround the lower rim of the base 190 . The short chin part may be in the form of a continuous band or in the form of some intermittent bands in the middle. The predetermined thickness of the stepped portion is equal to the thickness of the side of the cover can 102, and when the cover can 102 is mounted, seated, contacted, fixed, temporarily fixed, supported, combined, or placed on the base 190, the cover can The side of 102 may be mounted, seated, contacted, coupled, fixed, supported, or placed on the top or side of the stepped portion. Due to this, the cover can 102 coupled to the upper side of the stepped portion can be guided by the stepped portion, and also, the end of the cover can 102 can be coupled to surface contact with the stepped portion. Here, the end of the cover can 102 may include a bottom surface or a side surface. At this time, the stepped portion and the end of the cover can 102 may be adhesively fixed or coupled or sealed by an adhesive or the like.

In the stepped portion, a second groove portion 192 may be formed at a position corresponding to the first groove portion 104 of the cover can 102 . As described above, the second groove portion 192 is combined with the first groove portion 104 of the cover can 102 to form a concave portion, and may form a space filled with an adhesive member.

Like the cover can 102, the base 190 may include an opening near the center. The opening may be formed at a position corresponding to a position of an image sensor disposed in the camera module.

In addition, the base 190 may include four guide members 194 protruding at right angles to a predetermined height in an upward direction from four corner portions. The guide member 194 may have a polygonal columnar shape. The guide member 194 may be mounted, inserted, seated, contacted, coupled, fixed, supported, or placed in the lower guide groove 148 of the housing member 140, which will be described later. In this way, due to the guide member 194 and the lower guide groove 148 shown in FIG. 4 to be described later, the housing member 140 is mounted, seated, contacted, combined, fixed, supported, or When placed, the position of the coupling of the housing member 140 on the base 190 can be guided, the coupling area can be enlarged, and the housing member 140 vibrates during the operation of the lens driving device 100. It can be prevented from departing from the reference position to be mounted due to reasons such as or a worker's mistake during the assembly process.

4 is a schematic plan perspective view of a housing member 140 according to an embodiment, FIG. 5 is a schematic bottom perspective view of the housing member 140 according to an embodiment, and FIG. 6 is for driving according to an embodiment. A schematic exploded perspective view of the magnet 130, the housing member 140, the first circuit board 170, and the position sensor 180 is shown, and FIG. 7 shows a plan perspective view of the upper elastic member 150, FIG. 8 shows a planar perspective view of the lower elastic member 160 .

Referring to FIGS. 4 to 6 , the housing member 140 may have a hollow column shape as a whole (for example, a hollow quadrangular column shape as shown). The housing member 140 has a shape to support at least two or more driving magnets 130 and the first circuit board 170, and a bobbin 110 inside is provided in the first direction z with respect to the housing member 140. The bobbin 110 may be accommodated so as to be movable in the axial direction.

The housing member 140 may include four flat sides 141 . The side surface 141 of the housing member 140 may have an area corresponding to or larger than that of the driving magnet 130 .

As shown in FIG. 6 , a driving magnet 130 is mounted, inserted, seated, contacted, coupled, fixed, supported, or A through hole (or groove) 141a for a magnet that can be placed may be formed. The magnet through hole 141a may have a size and/or shape corresponding to the driving magnet 130, and may also have a shape capable of guiding the driving magnet 130. One of the driving magnets 130 (hereinafter referred to as 'first driving magnet 131') and the other one (hereinafter referred to as 'second driving magnet 131') are provided in each of the first and second through-holes 141a and 141a' for the magnets. The magnets 132′) may be mounted, inserted, seated, contacted, coupled, fixed, supported, or disposed, respectively. In the case of the embodiment, only a total of two driving magnets 130 are shown, but the embodiment is not limited thereto. That is, of course, four driving magnets 130 may be disposed.

The type of the above-described driving magnet 130 can be largely divided into ferrite, alnico, and rare earth magnets, and is divided into an inner magnetic type (Ptype) and an outer magnetic type (F-type) according to the shape of the magnetic circuit. can be classified. The embodiment is not limited to the type of the driving magnet 130.

And, among the four side surfaces 141 of the housing member 140, a position detection unit 180 to be described later is mounted, inserted, seated, contacted, combined, A through hole 141b or a groove (not shown) for a fixed, supported, or placed sensor may be formed. The through-hole 141b for the sensor has a size and shape corresponding to the position sensor 180 to be described later, and may be formed to be spaced apart from the first and second magnet through-holes 141a and 141a' by a predetermined distance. The positioning through hole 141b may be formed on a side surface of the side surface 141 of the housing member 140 on which the first circuit board 170 is mounted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed. there is.

In addition, on one side of the housing member 140, at least one mounting protrusion 149 to allow the first circuit board 170 to be mounted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed. can be provided.

The mounting protrusion 149 may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed in the mounting through-hole 173 formed in the first circuit board 170 . At this time, the mounting through-hole 173 and the mounting protrusion 149 may be contacted or coupled by a form fit method or an interference fit method, but they 173 and 149 are the first circuit board 170 Mounting on the member 140, seating, contact, coupling, fixing, temporary fixation, support, or placement may be simply guided.

Here, among the four side surfaces 141 of the housing member 140, the other side opposite to one side may be configured as a flat plane, but is not limited thereto.

Although not shown, through-holes for third and fourth magnets may be additionally disposed on the second side surfaces perpendicular to the first side surfaces of the housing member 140 .

At this time, the first magnet through-hole 141a and the second magnet through-hole 141a' have the same size and shape, and are (almost) identical over the entire lateral length of the first both sides of the housing member 140. It may have a lateral length. On the other hand, the through-holes for the third magnet and the through-holes for the fourth magnet have the same size and shape, but have a longer lateral length than the through-holes for the first magnet 141a and the through-holes for the second magnet 141a'. can be made small. This is to secure a space for the through-hole 141b for the sensor, since the through-hole 141b for the sensor must be formed on the second side surface where the through-hole for the third or fourth magnet is formed.

The first driving magnet 131 and the second driving magnet 132 have the same size and shape as each other, and have substantially the same lateral length over the entire lateral length of the first side surfaces of the housing member 140. It's like a bar. And, the third and fourth driving magnets (not shown) that can be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed in the through holes (not shown) for the third and fourth magnets, respectively. ) may have the same size and shape, and may have a smaller lateral length than the first driving magnet 131 and the second driving magnet 132 .

Here, like the first and second magnet through-holes 141a and 141a', the third and fourth magnet through-holes may be arranged symmetrically on a straight line with respect to the center of the housing member 140 . That is, the third and fourth driving magnets (not shown) may be disposed symmetrically on a straight line with respect to or with respect to the center of the housing member 140 .

If the first and second driving magnets 131 and 132 or the third and fourth driving magnets are disposed facing each other while being biased to one side regardless of the center of the housing member 140, the bobbin 110 Since the electromagnetic force acts on the first coil 120 to be biased to one side, there is a possibility that the bobbin 110 may be tilted. In other words, similarly to the first and second driving magnets 131 and 132, the bobbin 110 is formed by symmetrically arranging the third and fourth driving magnets on a straight line with respect to the center of the housing member 140. And it is possible to apply an electromagnetic force that is not deflected to the first coil 120, so that the movement of the bobbin 110 in the first direction can be easily and accurately guided.

Hereinafter, for convenience of description, it is assumed that the lens driving device 100 according to the embodiment has only the first and second driving magnets 131 and 132, but even when the third and fourth driving magnets are further included, the following The description of can be applied.

A plurality of first stoppers 143 may protrude from the upper surface of the housing member 140 . The first stopper 143 is to prevent collision between the cover can 102 and the body of the housing member 140, and when an external impact occurs, the upper surface of the housing member 140 is on the upper inner surface of the cover can 102. A direct collision can be prevented. In addition, the first stopper 143 may also serve to guide the installation position of the upper elastic member 150 . For example, referring to FIGS. 3 and 7 , a guide groove 155 having a shape corresponding to a position corresponding to the first stopper 143 in the upper elastic member 150 may be formed.

In addition, on the upper side of the housing member 140, a plurality of upper frame support protrusions 144 into which the outer frame 152 of the upper elastic member 150 is inserted, seated, contacted, fixed, temporarily fixed, coupled, supported, or disposed. may protrude. A first through hole (or groove) 152a having a corresponding shape may be formed in the outer frame 152 of the upper elastic member 150 corresponding to the upper frame supporting protrusion 144 . The upper frame support protrusion 144 may be inserted, seated, contacted, fixed, temporarily fixed, combined, supported, or placed in the first through hole 152a and then fixed with an adhesive or fusion, and the fusion is performed by thermal fusion or ultrasonic fusion. etc. may be included.

In addition, a plurality of lower frame support protrusions 147 coupled to the outer frame 162 of the lower elastic member 160 may protrude from the lower side of the housing member 140 . The lower frame support protrusions 147 may be formed at four lower corners of the housing member 140 , respectively. Meanwhile, referring to FIG. 8 , the outer frame 162 of the lower elastic member 160 is mounted, inserted, seated, contacted, or coupled to the lower frame support protrusion 147 at a position corresponding to the lower frame support protrusion 147. , A fastening part 162a that can be fixed, temporarily fixed, supported, or placed may be formed, and this place may be fixed with an adhesive or fusion, and the fusion may include thermal fusion or ultrasonic fusion.

Also, the housing member 140 may be a yoke housing member capable of functioning as a yoke. In the yoke housing member structure, the structure may be formed to be spaced apart from the inner surface of the upper elastic member 140 and the upper surface of the yoke. This is to prevent interference between the movement of the bobbin 110 in the upper direction and the yoke.

Alternatively, the yoke (not shown) itself may serve as the housing member 140 . In this case, the yoke may be coupled to the base 190, and the upper elastic member 150 may be disposed below the yoke or inside the yoke.

According to another embodiment, a separate cover may be further disposed above the yoke. In this case, the upper elastic member 150 may be disposed above the yoke or disposed between the yoke and the cover, and the upper elastic member 150 may be coupled to the cover or the yoke.

Meanwhile, the driving magnets 130: 131 and 132 may be fixed to the magnet through-holes 141a and 141a' with an adhesive, but are not limited thereto, and an adhesive member such as double-sided tape may be used. Alternatively, as a modified embodiment, instead of the first and second through-holes 141a and 141a' for the magnets, instead of the through-holes 141a and 141a', concave-shaped magnet seating portions (not shown) may be formed on the inner surface of the housing member 140 as shown in the drawings. And, the magnet seating portion may have a size and shape corresponding to the size and shape of the driving magnet 130 .

The driving magnet 130 may be installed at a position facing the first coil 120 located on the outer circumferential surface of the bobbin 110 . In addition, the driving magnet 130 may be configured separately as shown or may be configured as one body unlike shown. In the case of an embodiment, the driving magnet 130 may be disposed so that the side facing the first coil 120 of the bobbin 110 has the N pole and the outer side has the S pole. However, it is not limited thereto, and a converse configuration is also possible.

In addition, the driving magnet 130 may be divided into two planes perpendicular to the optical axis. That is, the driving magnet 130 is a positively magnetized magnet, and is composed of a first magnet (not shown) and a second magnet (not shown) disposed facing each other with a non-magnetic partition wall interposed therebetween in a plane perpendicular to the optical axis. can Here, the non-magnetic barrier rib may be air or a non-magnetic material. The first and second magnets may be disposed to have polarities opposite to each other, but the embodiment is not limited thereto and may have various forms.

The first and second driving magnets 131 and 132 are configured in a rectangular parallelepiped shape having a certain width and seated in the through holes 141a and 141a' for the first and second magnets, respectively, for the first and second driving. A wide surface or partial surface of the magnets 131 and 132 may form part of the side surface (outer surface or inner surface) of the housing member 140 . In addition, the first and second driving magnets 131 and 132 may be disposed on the side surface of the housing member 140 and also disposed or coupled to the inner surface of the yoke described above, and the inner surface of the yoke without the housing member 140. It may be coupled or fixed to the side. At this time, the driving magnets 131 and 132 facing each other may be installed parallel to each other. In addition, surfaces of the driving magnet 130 and the first coil 120 of the bobbin 110 facing each other may be flatly arranged so as to be parallel to each other. However, this is not limited thereto, and depending on the design, only one of the driving magnet 130 and the first coil 120 of the bobbin 110 may be a flat surface, and the other may be a curved surface. Alternatively, all of the facing surfaces of the first coil 120 of the bobbin 110 and the driving magnet 130 may be curved surfaces. In this case, the first coil 120 of the bobbin 110 and the driving magnet 130 ), the curvature of the facing surface may be formed the same.

In addition, as described above, a sensor through hole 141b or a groove is provided on one side of the housing member 140, and the position sensor 180 is mounted, inserted, or inserted into the sensor through hole 141b or the groove. It is seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed, and the position sensor 180 may be electrically coupled to one surface of the first circuit board 170 by soldering or soldering. In other words, the first circuit board 170 is mounted, inserted, seated, contacted, or coupled to the outer surface of one of the four side surfaces 141 of the housing member 140 where the sensor through-hole 141b or groove is provided. , can be fixed, temporarily anchored, supported, or positioned.

The position detector 180 may sense/determine the position of the bobbin 110 in the first direction together with the sensing magnet 182 to be described later. To this end, the position sensor 180 and the through hole 141b or groove for the sensor may be disposed at a position corresponding to the position of the magnet 182 for sensing. As shown, the sensing magnet 182 may be divided into two upper and lower parts in order to increase the strength of the magnetic field, but the embodiment is not limited thereto.

The position detector 180 may be a sensor that detects a change in magnetic force emitted from the sensing magnet 182 of the bobbin 110 . For example, the position sensor 180 may be a Hall sensor, but the embodiment is not limited thereto. According to another embodiment, any sensor other than a hall sensor capable of detecting a change in magnetic force may be used as the position sensor 180, and any sensor capable of detecting a position other than magnetic force may be used. For example, a method using a photo reflector or the like is also possible. When the position sensor 180 is implemented as a Hall sensor, calibration of the actuator driving distance may be additionally performed based on a Hall voltage difference for a change in magnet flux (ie, magnetic flux density) detected by the Hall sensor. .

For example, when the position sensor 180 is implemented as a hall sensor, the hall sensor 180 may have a plurality of pins. For example, the plurality of pins may include first and second pins. The first pin may include 1-1 and 1-2 pins connected to voltage and ground, respectively, and the second pin may include 2-1 and 2-2 pins outputting the sensed result. can Here, the sensed result output through the 2-1 and 2-2 pins may be in the form of a current, but the embodiment is not limited to the form of a signal. The first circuit board 170 is connected to the hall sensor 180 to supply power to pins 1-1 and 1-2 and to receive signals from pins 2-1 and 2-2. can

The first circuit board 170 may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on one side of the housing member 140 . At this time, the installation position of the first circuit board 170 may be guided by the mounting protrusion 149 formed on one side of the housing member 140 as described above. One or more mounting protrusions 149 may be formed, and if two or more are formed, it may be easier to guide the arrangement position of the first circuit board 170 .

In addition, a plurality of terminals 171 are disposed on the first circuit board 170 to receive external power and supply current required by the first coil 120 of the bobbin 110 and the position sensor 180. . The number of terminals 171 formed on the first circuit board 170 may be increased or decreased according to the types of components requiring control.

Also, referring to FIGS. 3 and 6 , at least one pin 172 may be provided on the first circuit board 170 . As shown, there may be four pins 172, but the number of pins 172 may be more or less than four. For example, the four pins 172 may be test pins, hole pins, VCM+ pins, and VCM- pins, but the embodiment is not limited to these types of pins. Here, the test pin may be a pin used to evaluate the performance of the lens driving devices 100A and 100B. The hole pin may be a pin used to retrieve data output from the position sensor 180 . The VCM+ pin and the VCM− pin may be pins used to evaluate the performance of the lens driving devices 100A and 100B without receiving feedback from the position sensor 180 .

According to the embodiment, the first circuit board 170 may be provided as a flexible printed circuit board (FPCB). The first circuit board 170 may include a focus controller 300 to be described later. For example, the focus controller 300 may receive signals from pins 2-1 and 2-2 of the hall sensor 180 as position information. The focus controller 300 may be mounted on the first circuit board 170 . Alternatively, according to another embodiment, the focus controller 300 may be mounted on a separate board instead of being mounted on the first circuit board 170 . Here, the separate board may be a second circuit board (not shown) on which an image sensor (not shown) is mounted in the camera module or may be a separate board.

In addition, in the above example, the first circuit board 170 has been described as being mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the outer surface of the housing member 140. is not limited to That is, according to another embodiment, the first circuit board 170 may be located under the housing member 140 instead of the outer surface of the housing member 140 .

According to one embodiment, the cover can 102 may be a yoke cover can capable of performing a yoke function. In addition, the cover can 102a may be formed of a sus material, a magnetic material, or a metal material, but is not limited thereto, and any material having electrical conductivity is possible.

According to another embodiment, the lens driving device 100 may further include a cover although not shown. The cover may be wrapped by the cover can 102 and fixedly support the bobbin 110 . The driving magnet 130 may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed inside the cover.

FIG. 9 shows a plan perspective view of the bobbin 110 shown in FIG. 2 according to an embodiment, and FIG. 10 shows a bottom perspective view of the bobbin 110 shown in FIG. 2 according to an embodiment.

Referring to FIGS. 4 and 5 and FIGS. 7 to 10 , the upper elastic member 150 and the lower elastic member 160 may elastically support the upward and/or downward motion of the bobbin 110 in the optical axis direction. . The upper elastic member 150 and the lower elastic member 160 may be provided as leaf springs, but the embodiment is not limited to the shape of the upper and lower elastic members 150 and 160, respectively.

The upper elastic member 150 includes an inner frame 151 coupled to the bobbin 110, an outer frame 152 coupled to the housing member 140, and a connection portion connecting the inner frame 151 and the outer frame 152. (153) may be included.

In addition, the lower elastic member 160 connects the inner frame 161 coupled to the bobbin 110, the outer frame 162 coupled to the housing member 140, and the inner frame 161 and the outer frame 162. It may include a connection portion 163 to.

The connecting portions 153 and 163 may be bent at least once to form a pattern having a predetermined shape. The bobbin 110 may be elastically (or elastically) supported for an upward and/or downward motion in a first direction, which is an optical axis direction, through a change in position and fine deformation of the connecting parts 153 and 163 .

According to one embodiment, as shown in FIG. 7 , the upper elastic member 150 includes a plurality of first through-holes 152a in the outer frame 152 and a plurality of second through-holes in the inner frame 151. (151a).

The first hole 152a is coupled with the upper frame support protrusion 144 formed on the upper surface of the housing member 140, and the second through hole 151a is the upper support protrusion 113 formed on the upper surface of the bobbin 110. can be combined with The upper support protrusion 113 will be described later in detail. That is, the outer frame 152 is mounted, seated, contacted, fixed, temporarily fixed, supported, disposed, or coupled to the housing member 140 through the first through hole 152a, and the inner frame 151 is formed through the second through hole. It can be mounted, seated, contacted, fixed, temporarily fixed, supported, arranged, or coupled to the bobbin 110 through (151a).

The connecting portion 153 of the upper elastic member 150 connects the inner frame 151 and the outer frame 152 such that the inner frame 151 is elastically deformable in a predetermined range with respect to the outer frame 152 in a first direction. can

At least one of the inner frame 151 and the outer frame 152 of the upper elastic member 150 has a terminal portion electrically connected to at least one of the first coil 120 or the first circuit board 170 of the bobbin 110. may include at least one.

Referring to FIG. 8 , the lower elastic member 160 includes a plurality of fastening parts 162a in the outer frame 162 and a plurality of third through holes (or grooves) 161a in the inner frame 161. can include

As described above, the fastening part 162a may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the lower surface of the housing member 140, and the third through hole 161a is shown in FIG. It can be contacted, combined, fixed, or temporarily fixed with the lower support protrusion 114 formed on the lower surface of the bobbin 110 shown in FIG. That is, the outer frame 162 may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the housing member 140 through the fastening portion 162a, and the inner frame 161 It may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the bobbin 110 through the third through hole 161a.

The connecting portion 163 of the lower elastic member 160 connects the inner frame 161 and the outer frame 162 such that the inner frame 161 is elastically deformable in a predetermined range with respect to the outer frame 162 in a first direction. can

The lower elastic member 160 may include a first lower elastic member 160a and a second lower elastic member 160b separated from each other. Through this two-part structure, the first lower elastic member 160a and the second lower elastic member 160b of the lower elastic member 160 may receive power of different polarities or different currents. That is, after the inner frame 161 and the outer frame 162 are coupled to the bobbin 110 and the housing member 140, respectively, the inner side corresponding to both end lines of the first coil 120 disposed on the bobbin 110. A solder portion may be provided at a position of the frame 161, and a conductive connection such as soldering may be performed at the solder portion to receive power of different polarities or different currents. In addition, the first lower elastic member 160a is electrically connected to one of the both end lines of the first coil 120, and the other one of the both end lines of the first coil 120 and the second lower elastic member 160b are Electrically connected, current and/or voltage may be applied from the outside. To this end, at least one of the inner frame 161 and the outer frame 162 of the lower elastic member 160 is electrically connected to at least one of the first coil 120 or the first circuit board 170 of the bobbin 110. It may include at least one terminal connected to. Both end lines of the first coil 120 may be disposed on opposite sides of the bobbin 110, or may be disposed adjacent to each other on the same side.

Meanwhile, the upper elastic member 150 and the lower elastic member 160, the bobbin 110, and the housing member 140 may be assembled through thermal fusion and/or bonding using an adhesive. At this time, it is possible to finish the fixing work by bonding using an adhesive after fixing by thermal fusion according to the assembly sequence.

As another embodiment, the upper elastic member 150 may be configured as a two-part structure as illustrated in FIG. 8 and the lower elastic member 160 may be configured as an integral structure as illustrated in FIG. 7 .

11 is an exploded perspective view of a bobbin 110, a first coil 120, a position sensor 180, and a sensing magnet 182 according to an embodiment, and FIG. 12 is a bobbin 110 according to an embodiment. ), a schematic bottom perspective view of the first coil 120, the first and second driving magnets 131 and 132, the position sensor 180, and the sensing magnet 182.

The bobbin 110 may be installed in the inner space of the housing member 140 to be reciprocally movable in the optical axis direction. A first coil 120 is installed on the outer circumferential surface of the bobbin 110 to electromagnetically interact with the driving magnet 130 of the housing member 140 to reciprocate the bobbin 110 in a first direction.

In addition, the bobbin 110 is elastically (or elastically ) can be supported.

Although not shown in the bobbin 110, at least one lens may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed therein. For example, the bobbin 110 may include an installed lens barrel (not shown). The lens barrel is a component of a camera module to be described later and may not be an essential component of the lens driving device 100 . The lens barrel may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed inside the bobbin 110 in various ways. For example, female threads may be formed on the inner circumferential surface of the bobbin 110 and male threads corresponding to the female threads may be formed on the outer circumferential surface of the lens barrel, and the lens barrel may be coupled to the bobbin 110 by screwing the threads. However, this is not limited thereto, and the lens barrel may be directly fixed to the inside of the bobbin 110 by a method other than screwing without forming a screw thread on the inner circumferential surface of the bobbin 110 .

Alternatively, one or more lenses may be integrally formed with the bobbin 110 without a lens barrel. A lens coupled to the lens barrel may be composed of one sheet, or two or more lenses may form an optical system.

In addition, a plurality of upper support projections 113 and a plurality of lower support projections 114 may protrude from the upper and lower surfaces of the bobbin 110 , respectively. As shown in FIG. 9, the upper support protrusion 113 may be provided in a cylindrical shape or a prismatic shape, and the inner frame 151 of the upper elastic member 150 and the bobbin 110 are coupled, fixed, and temporarily fixed. , contact, or support. According to the embodiment, the second through hole 151a may be formed at a position corresponding to the upper support protrusion 113 of the inner frame 151 of the upper elastic member 150 . At this time, the upper support protrusion 113 and the second through hole 151a may be fixed by thermal fusion or by an adhesive material such as epoxy. In addition, a plurality of upper support protrusions 113 may be provided. At this time, the distance between each of the upper support protrusions 113 may be appropriately arranged within a range in which interference with neighboring parts can be avoided. That is, each of the upper support protrusions 113 may be arranged at regular intervals symmetrically with respect to the center of the bobbin 110, and their intervals are not constant, but on a specific imaginary line passing through the center of the bobbin 110. It may be formed to be symmetrical with respect to

As shown in FIG. 10, the lower support protrusion 114 may be provided in a cylindrical shape or a prismatic shape like the upper support protrusion 113, and the inner frame 161 and the bobbin 110 of the lower elastic member 160 can be coupled, fixed, temporarily fixed, contacted, or supported. According to the embodiment, a third through hole 161a may be formed at a position corresponding to the lower support protrusion 114 of the inner frame 161 of the lower elastic member 160 . In this case, the lower support protrusion 114 and the third through hole 161a may be fixed by thermal fusion or by an adhesive material such as epoxy. In addition, a plurality of lower support protrusions 114 may be provided as shown in FIG. 10 . At this time, the distance between each of the lower support protrusions 114 may be appropriately arranged within a range in which interference with neighboring parts can be avoided. That is, each of the lower support protrusions 114 may be arranged at regular intervals symmetrically with respect to the center of the bobbin 110 .

And, on the upper and lower surfaces of the bobbin 110, upper escape grooves 112 and lower escape grooves 112 are provided at positions corresponding to the connecting parts 153 of the upper elastic member 150 and the connecting parts 163 of the lower elastic member 160. Escape grooves 118 may be formed respectively.

Since the upper escape groove 112 and the lower escape groove 118 are provided, spatial interference between the connecting parts 153 and 163 and the bobbin 110 when the bobbin 110 moves in the first direction with respect to the housing member 140 This is removed so that the elastic deformation of the connection parts 153 and 163 can be more easily performed. In addition, the location of the upper escape groove 112 may be disposed at the corner of the housing member 140 as illustrated in FIG. 9, but may also be disposed at the side depending on the shape and/or location of the connection part of the elastic member.

In addition, on the outer circumferential surface of the bobbin 110, a seating groove 116 for a coil in which the first coil 120 is mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed may be provided, Examples are not limited thereto. That is, according to another embodiment, the first coil 120 is directly mounted on the outer circumferential surface of the bobbin 110, inserted, seated, contacted, combined, fixed, temporarily fixed, supported, or disposed instead of the bobbin 110 A coil ring (not shown) having the same shape as the outer circumference of the bobbin 110 is mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed adjacent to the outer circumferential surface of the bobbin 110, and the first coil 120 ) may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the coil ring.

The first coil 120 is provided as a ring-shaped coil block that is mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the outer circumferential surface of the bobbin 110 or the coil seating groove 116. However, this is not limited, and the first coil 120 may be directly wound on the outer circumferential surface of the bobbin 110 or the seating groove 116 for the coil. When the pre-wound first coil 120 is mounted or inserted or placed, it may be mounted or inserted or placed from the top or bottom of the bobbin 110.

According to an embodiment, the first coil 120 may be formed in an approximately octagonal shape as shown in FIG. 11 . This is a shape corresponding to the shape of the outer circumferential surface of the bobbin 110, and the bobbin 110 may also have an octagonal shape. In addition, at least four surfaces of the first coil 120 may be provided as straight lines, and corner portions connecting these surfaces may be implemented as round or straight lines. At this time, the portion formed as a straight line may be a surface corresponding to the driving magnet 130 . Also, a surface of the driving magnet 130 corresponding to the first coil 120 may have the same curvature as that of the first coil 120 . That is, if the first coil 120 is straight, the corresponding side of the driving magnet 130 may be a straight line, and if the first coil 120 is curved, the corresponding side of the driving magnet 130 is curved. , and may also have the same curvature. Also, even if the first coil 120 is curved, the corresponding side of the driving magnet 130 may be straight or vice versa.

The first coil 120 is for moving the bobbin 110 in the optical axis direction when performing an auto focus function, and when current is supplied, it can electromagnetically interact with the driving magnet 130 to form electromagnetic force, It is as described above that the formed electromagnetic force can move the bobbin 110 to move it.

On the other hand, the first coil 120 may be configured to correspond to the driving magnet 130. As shown, the driving magnet 130 is composed of a single body, and the entire surface facing the first coil 120 is formed. When is provided to have the same polarity, the first coil 120 may also be configured such that a surface corresponding to the driving magnet 130 has the same polarity. On the other hand, although not shown, if the driving magnet 130 is divided into two on a plane perpendicular to the optical axis and the plane facing the first coil 120 is divided into two or more, the first coil 120 It is also possible to be divided into a number corresponding to the divided driving magnet 130.

Meanwhile, the lens driving device 100 may further include a magnet 182 for sensing. The sensing magnet 182 may be mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed on the bobbin 110 . Due to this, when the bobbin 110 moves in the first direction, the sensing magnet 182 may move in the first direction by the same displacement amount as the bobbin 110 . In addition, the sensing magnet 182 may be integrally formed with the bobbin 110, and may be arranged so that the upper direction of the bobbin 110 becomes the N pole and the lower direction of the bobbin 110 becomes the S pole. However, it is not limited thereto, and a converse configuration is also possible.

In addition, the sensing magnet 182 may be divided into two planes perpendicular to the optical axis. As illustrated in FIGS. 9 to 12 , the bobbin 110 may further include an accommodation groove 117 for accommodating the sensing magnet 182 on the outer circumferential surface of the bobbin 110 .

The accommodation groove 117 may be formed from the outer surface of the bobbin 110 toward the inside of the bobbin 110 at a predetermined depth. Specifically, the accommodating groove 117 may be formed on one side of the bobbin 110 such that at least a portion of the accommodating groove 117 is located inside the first coil 120 .

In addition, at least a portion of the accommodating groove 117 may be formed to be recessed to a predetermined depth in the inner direction of the bobbin 110 more than the seating groove 116 for the coil. In this way, by forming the accommodating groove 117 toward the inside of the bobbin 110, the sensing magnet 182 can be accommodated inside the bobbin 110, whereby a separate sensor for the sensing magnet 182 can be accommodated. Since there is no need to secure an installation space, space efficiency of the bobbin 110 can be improved.

In particular, the accommodating groove 117 may be disposed at a position corresponding to the position of the position detecting unit 180 of the housing member 140 or at a position opposite to the position detecting unit 180 . Due to this, the position sensor 180 and the sensing magnet 182 may be aligned on the same axis.

The distance d between the sensing magnet 182 and the position detector 180 can be minimized as the thickness of the first coil 120 and the separation distance between the first coil 120 and the position detector 180. Therefore, the magnetic force sensing accuracy of the position sensor 180 can be improved.

More specifically, as illustrated in FIGS. 9 to 12 , the receiving groove 117 has an inner surface on which one surface of the magnet 182 for sensing is supported and a predetermined depth deeper than the inner surface so that the adhesive can be injected. It may include a concavely formed adhesive groove (117b).

The inner surface is one surface located in an inward direction toward the center of the bobbin 110, and is a surface on which the wide surface of the sensing magnet 182 contacts or is seated when the sensing magnet 182 has a rectangular parallelepiped shape.

The bonding groove 117b may be a groove formed by deeply concave a portion of the inner surface in an inward direction toward the center of the bobbin 110 . The adhesive groove 117b may be formed to an inner surface of the bobbin 110 on which one surface of the sensing magnet 182 is mounted, inserted, seated, contacted, coupled, fixed, temporarily fixed, supported, or disposed.

As another embodiment, the receiving groove 117 is formed from an inner surface where one surface (ie, a wide surface) of the sensing magnet 182 is supported to an outer circumferential surface where the second coil 120 is provided (ie, a seating groove 116 for a coil). ) surface) may be less than or equal to the thickness of the sensing magnet 182 . Due to this, the sensing magnet 182 may be fixed in the receiving groove 117 by an inner pressing force of the first coil 120 due to winding of the first coil 120 . In this case, it may not be necessary to use an adhesive.

As an additional embodiment, although not shown in the drawings, the bobbin 110 is positioned symmetrically with the receiving groove 117 based on the center of the bobbin 110 on the outer circumferential surface facing the outer circumferential surface on which the receiving groove 117 is formed ( 110) may further include an additional accommodating groove formed on an outer circumferential surface and a weight balancing member accommodated in the additional accommodating groove.

According to the embodiment, the magnet 182 for sensing may be omitted. In this case, the driving magnet 130 may be used instead of the sensing magnet 182 .

In addition, the embodiment can minimize the distance between the sensing magnet 182 provided on the bobbin 110, which is a moving object, and the position sensor 180 provided on the housing member 140, which is a fixed object. Since the amount of displacement in the direction of the optical axis can be detected more accurately, the lens can be more accurately positioned at the focal length of the lens.

In addition, in the embodiment, the sensing magnet 182 is mounted, seated, contacted, fixed, temporarily fixed, coupled, supported, or disposed inside the bobbin 110, and the position sensor 180 is placed inside the housing member 140. By mounting, seating, contacting, fixing, temporarily fixing, combining, supporting, or arranging, the space efficiency of the camera module (in particular, the bobbin) is improved because a separate space for mounting the position sensor 180 is not required. can make it

In addition to the above-described lens driving device 100, the camera module of the embodiment includes a lens mounted, inserted, seated, contacted, coupled, fixed, supported, or disposed in the lens driving device 100, and an image sensor (not shown) below. , a second circuit board (not shown) on which an image sensor is disposed (or a main circuit board) and an optical system. At this time, the camera module according to the embodiment may further include a lens barrel coupled to the bobbin 110 .

The lens barrel is as described above, and the second circuit board may form a bottom surface of the camera module from a portion where the image sensor is mounted. Also, the optical system may include at least one or more lenses that transmit images to the image sensor.

Meanwhile, an actuator module capable of performing an auto-focus function and an image stabilization function may be installed in the optical system. An actuator module performing an auto focus function may be configured in various ways, and a voice coil unit motor is generally used. The lens driving device 100 according to the above-described embodiment may correspond to an actuator module that performs an auto-focus function under the control of the focus controller 300 . However, the embodiment is not limited to the actuator module performing the auto-focus function, and may be applied to an actuator module that performs both the auto-focus function and the hand-shake compensation function.

Although not shown, when a second coil (not shown), a support member (not shown), and a plurality of detectors (not shown) are added to the lens driving device 100 that performs the above-described autofocus function, The lens driving device 100 may perform not only an auto focus function but also a hand shake correction function. Here, the second coil may be disposed to face the driving magnet. That is, the second coil is disposed so that the bottom surface of the driving magnet 130 directly faces the second coil, and each of the plurality of sensing units may be implemented as, for example, a hall sensor, and each of the plurality of sensing units and the second coil The two coils and the driving magnet may be disposed on the same axis. Accordingly, the second coil may perform hand shake correction by moving the housing member 140 on which the bobbin 110 is mounted in the second and/or third directions through interaction with the driving magnet 130 .

At this time, a support member is disposed on the upper surface of the base 190 to elastically (or elastically) support the horizontal motion of the housing member 140 moving in a direction perpendicular to the first direction.

In addition, the camera module may further include an infrared cut filter (not shown). The infrared cut filter serves to block light in the infrared region from being incident on the image sensor. In this case, in the base 190 illustrated in FIG. 2 , an infrared cut filter may be installed at a position corresponding to the image sensor and may be coupled to a holder member (not shown). In addition, the base 190 may support the lower side of the holder member.

A separate terminal member may be installed on the base 190 to conduct electricity with the second circuit board, or the terminal may be integrally formed using a surface electrode or the like. Meanwhile, the base 190 may function as a sensor holder to protect the image sensor, and in this case, a protrusion may be formed downward along a side surface of the base 190 . However, this is not an essential configuration, and although not shown, a separate sensor holder may be disposed under the base 190 to perform its role.

Hereinafter, the configuration and operation of the focus controller 300 will be described with reference to FIGS. 13 to 17 attached. For convenience, the focus controller 300 is described with reference to the aforementioned lens driving device 100, but the embodiment is not limited thereto. That is, it goes without saying that the focus controller 300 according to the embodiment can be applied to a lens driving device having a configuration different from that of the aforementioned lens driving device 100 to perform an auto focus function. That is, as long as the lens driving device can move the bobbin 110 in the optical axis direction by the interaction between the first coil 120 and the driving magnet 130, this applies to the lens driving device having any configuration and controls the focus. 300 may perform an auto focus function.

13 is a flowchart for explaining an auto-focus function (or a method of performing the auto-focus function) 200 performed by the focus controller 300 of a camera module according to an embodiment, and FIG. 14 is an exemplary embodiment. A block diagram of the focus controller 300 is shown.

13 and 14, the focus controller 300 controls the interaction between the first coil 120 and the driving magnet 130 according to subject information and location information output from the location sensor 180, , The auto focus function may be performed by moving the bobbin 110 by a first movement amount (or a first displacement amount) in a first direction parallel to the optical axis. To this end, the focus controller 300 may include an information receiver 310, a bobbin position search unit 320, and a movement amount controller 330.

The position detector 180 may detect the position of the bobbin 110 in the direction of the optical axis and output the detected result to the movement amount controller 330 as position information.

The information receiving unit 310 may receive subject information through the input terminal IN1 (step 210). Here, the subject information may include at least one of a distance between the subject and at least one lens (not shown), a distance between the subject and an image sensor, a position of the subject, or a phase of the subject. Subject information may be obtained in various ways.

According to an embodiment, subject information may be acquired using two cameras.

According to another embodiment, object information may be obtained using a laser. For example, Korean Publication No. 1989-0008573 discloses a method of measuring a distance to an object using a laser.

According to another embodiment, object information may be obtained using a sensor. For example, US Patent Publication No. US2013/0033572 filed by Sony discloses a method of obtaining a distance between a camera and a subject using an easy sensor.

The above-described subject information may be provided to, received from, or accepted by the camera module from outside the camera module. For example, when the camera module according to the embodiment is applied to a mobile terminal (or portable terminal), subject information may be obtained from the mobile terminal, and the acquired subject information may be provided to the focus controller 300 of the camera module. . In this case, subject information may be provided to the information receiving unit 310 from the image sensor of the camera module. That is, the image sensor may provide subject information to the information receiver 310 of the focus controller 300 . However, according to another embodiment, the above-described subject information may be acquired by the camera module according to the embodiment.

After step 210, the bobbin position search unit 320 may find the position of the bobbin 110 that is in focus corresponding to the subject information received from the information receiver 310 (operation 220). To this end, for example, the bobbin position search unit 320 may include a data extraction unit 322 and a look up table (LUT) 324.

The lookup table 324 may map and store the location of the bobbin 110 that is in focus for each subject information. For example, the position of the bobbin 110 that is in focus according to the distance between the subject and the lens may be obtained in advance and stored in the form of a look-up table 324 . That is, the lookup table 324 may be generated in advance using the position sensor 180 before moving the bobbin 110 by the first movement amount in step 230 . For example, the position of the bobbin 110 for each subject information may be calculated in advance based on the current change value sensed by the position detector 180 . Accordingly, the lookup table 324 may be generated by measuring the position of the bobbin 110 when focus is achieved for each subject information, which is the distance between the subject and the lens. In addition, the look-up table 324 may code and store the position of the bobbin 110 .

The data extractor 322 receives the subject information received from the information receiver 310, extracts the position of the bobbin 110 in focus corresponding to the subject information from the look-up table 324, and extracts the bobbin 110 ) may be output to the movement amount controller 330. As described above, when the position of the bobbin 110 is coded and stored in the look-up table 324, the data extractor 322 may find a code value corresponding to the subject information in the look-up table 324. .

After step 220, the movement amount control unit 330 may move the bobbin 110 to the position found by the bobbin position search unit 320 by a first movement amount (or first displacement amount) (step 230). At this time, when performing step 230, the movement amount controller 330 may refer to the location information output from the location sensor 180 and received through the input terminal IN2. That is, the current position of the bobbin 110 may be determined based on the positional information provided from the position sensor 180, and the bobbin 110 may be moved to a corresponding position based on the identified current position of the bobbin 110. .

For example, the movement amount controller 330 may move the bobbin 110 in the first direction by a first movement amount by adjusting the amount of current applied to the first coil 120 . To this end, the amount of current for each position of the bobbin 110 may be determined in advance.

For example, the position sensor 180 fixedly coupled to the housing member 140 moves in the first direction of the sensing magnet 182 fixedly coupled to the movable bobbin 110 in the sensing magnet 182. Detect changes in the emitted magnetic force. At this time, the amount of current change output based on the amount of change in magnetic force detected by the position sensor 180 is received and checked as position information, and based on this, the movement amount controller 330 calculates or determines the current position of the bobbin 110. The applied current amount for moving the bobbin 110 to the focused position by the first movement amount may be determined with reference to the current position of the bobbin 110 calculated or determined in this way.

15 (a) and (b) are graphs for explaining an autofocus function according to a comparative example. In FIG. 15 (a), the horizontal axis represents a focus value, the vertical axis represents displacement, and in FIG. 15 (b), the horizontal axis represents a displacement. Current (or time) is represented, and the vertical axis represents displacement (or code).

16 (a) and (b) are graphs for explaining an autofocus function according to an embodiment. In FIG. 16 (a), the horizontal axis represents a focus value, the vertical axis represents displacement, and in FIG. 16 (b), the horizontal axis represents a displacement. Current (or time) is represented, and the vertical axis represents displacement (or code).

15 (a) and (b), from a first reference focal distance (Infinity) at a position where the lens and the image sensor are farthest to a second reference focal distance (Macro) at a position where the lens and the image sensor are closest The position (or displacement) 400 of the bobbin 110 with the best focus is found while increasing the current until . The bobbin 110 may not be driven during an initial predetermined time (P) during which current is applied. Thereafter, the displacement of the bobbin 110 increases as the current 402 (or the code value 404 corresponding to the amount of change in the magnetic force detected by the position sensor 180) continues to increase. In the comparative example, since the bobbin 110 is moved from the first reference focal distance to the second reference focal distance, the position 400 of the bobbin 110 with the best focus is found, so it may take a lot of time.

On the other hand, referring to FIG. 16 (a) and (b), the code for the position of the bobbin 110 where the lens is in focus is found in the look-up table 324 using subject information, and based on this, the bobbin 110 ) can be immediately moved (410) to the focal position (or displacement). Therefore, it can be seen that the time required to focus the lens is shortened compared to the comparative example described above.

Referring again to FIG. 13 , after the lens is focused through steps 210 to 230 described above, the focus of the lens may be finely adjusted (steps 240 to 260 ).

After performing step 230 of moving the bobbin 110 by a first movement amount, the focus controller 300 moves the bobbin 110 within a range of a second movement amount smaller than the first movement amount, thereby moving the bobbin 110 to a frequency modulation transfer function (MTF). The focus position 400 of the bobbin 110 showing the largest value among :Modulation Transfer function) values can be found (step 240). Here, the MTF value may be a numerical value of resolution.

After step 240, the focus controller 300 determines whether the bobbin 110 has been moved for a predetermined period to find the largest MTF value (step 250). Alternatively, in order to find the largest MTF value, the selection control unit 300 may determine whether the bobbin 110 has been moved a predetermined number of times (step 250). Alternatively, the bobbin 110 may be continuously moved over a predetermined period or over a predetermined number of times until the largest MTF value is found.

If it is determined that the bobbin 110 has been moved for a predetermined period or a predetermined number of times, the position of the bobbin 110 showing the largest MTF value is finally determined as the final focal position where the lens is focused (step 260).

17 (a) and (b) are graphs for explaining fine adjustment in the auto focus function according to the embodiment, in FIG. 17 (a), the horizontal axis represents the focus value and the vertical axis represents displacement, and FIG. 17 (b) In , the abscissa axis represents current (or time), and the ordinate axis represents displacement (or code).

17 (a) and (b) , after steps 210 to 230 are performed to primarily focus the lens (410), steps 240 to 260 are performed to finely focus the lens. (420) can.

By performing the above-described steps 240 to 260, the camera module according to the embodiment can improve resolution by precisely adjusting the focus of the lens.

Although the above has been described with reference to the embodiments, these are only examples and do not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100: lens driving device 102: cover can
104: first groove portion 106: third groove portion
110: bobbin 112: upper escape groove
118: lower escape groove 113: upper support projection
114: lower support projection 116: seating groove for coil
117: receiving groove 117b: bonding groove
120: first coil 130, 131, 132: driving magnet
140: housing member 141: side surface of housing member
141a, 141a': Through-hole for magnet 141b: Through-hole for sensor
143: first stopper 144: upper frame support protrusion
147: lower frame support protrusion 148: lower guide groove
149: mounting protrusion 150: upper elastic member
151, 161: inner frame 151a: second through hole
152, 162: outer frame 153, 163: connection part
152a: first through hole 155: guide groove
160, 160a, 160b: lower elastic member 161a: third through hole
162a: fastening part 170: first circuit board
171: terminal of the first circuit board 172: various pins
173: through-hole for mounting 180: position sensor
182: magnet for sensing 190: base
192: second groove portion 194: guide member
300: focus controller 310: information receiver
320: bobbin position search unit 322: data extraction unit
324: look-up table 330: movement amount control unit

Claims (24)

cover member;
a bobbin disposed within the cover member and including an outer circumferential surface and a receiving groove formed on the outer circumferential surface;
a position detector for detecting a position of the bobbin in an optical axis direction;
a sensing magnet disposed in the receiving groove of the bobbin at a position corresponding to the position sensor;
a first coil disposed on the outer circumferential surface of the bobbin;
a driving magnet facing the first coil; and
The sensing magnet is bonded to the receiving groove of the bobbin with an adhesive,
The sensing magnet includes a surface spaced apart from an inner surface of the receiving groove and facing the inner surface of the receiving groove,
At least a portion of the adhesive is disposed between the one surface of the sensing magnet and the inner surface of the receiving groove. According to claim 1,
The cover member includes a top plate and a side plate,
The side plate of the cover member includes first and second side plates facing each other; and third and fourth side plates facing each other;
The driving magnet includes first and second magnets respectively disposed on the first and second side plates,
The receiving groove is a camera module formed on a side surface of the bobbin corresponding to the third side plate of the cover member. According to claim 1,
The outer circumferential surface of the bobbin is a camera module having a coil seating groove formed on an outer surface of the bobbin. According to claim 1,
The distance between the sensing magnet and the position detector
The camera module is equal to or greater than the sum of the thickness of the first coil and the separation distance between the first coil and the position sensor. According to claim 1,
The receiving groove is
A camera module including a groove formed more concavely in a radially inner direction of the bobbin than the inner surface. According to claim 1,
The receiving groove is disposed at a position corresponding to the position detecting unit, so that the position detecting unit and the sensing magnet face each other. According to claim 2,
A camera module including a first circuit board disposed on the third side plate of the cover member. According to claim 2,
Includes a base coupled to the cover member,
The bobbin, the first coil, the driving magnet, the position detector, and the sensing magnet are disposed in a space between the cover member and the base. According to claim 8,
a first circuit board disposed on the third side plate of the cover member; and
Includes a housing member disposed within the cover member,
The first circuit board is disposed between the housing member and the third side plate of the cover member. 8. The method of claim 7, wherein the first circuit board
a plurality of terminals transmitting data about the location output from the location sensor; and
A camera module comprising a plurality of terminals for supplying a current required by the position sensor or a current to the first coil. According to claim 7,
A focus controller controlling interaction between the first coil and the driving magnet according to given subject information and the location to move the bobbin to perform an auto focus function;
The focus controller is disposed on the first circuit board. According to claim 2,
an upper elastic member having a first through hole coupled with an upper support protrusion formed on an upper surface of the bobbin; and
A camera module comprising a lower elastic member having a second through hole coupled with a lower support protrusion formed on a lower surface of the bobbin. According to claim 12,
The lower elastic member is
a first lower elastic member connected to one of both end lines of the first coil; and
A camera module including a second lower elastic member connected to the other one of the both end lines of the first coil and spaced apart from the first lower elastic member. According to claim 13,
a first circuit board disposed at a position corresponding to the third side plate of the cover member; and
Includes a housing member disposed within the cover member,
Each of the first and second lower elastic members
an inner frame coupled to the bobbin; and
Including an outer frame coupled to the housing member,
At least one of the inner frame and the outer frame of each of the first and second lower elastic members is electrically connected to at least one of the first coil or the first circuit board. According to claim 13,
The both end lines of the first coil are disposed on opposite sides of each other with respect to an optical axis. According to claim 12,
At least one of the upper elastic member and the lower elastic member is bonded to the bobbin by fusion bonding. According to claim 12,
The upper support projections include upper support projections disposed opposite to each other with respect to the optical axis,
The lower support protrusions include lower support protrusions disposed opposite to each other with respect to the optical axis. a moving body including a first groove;
a position detector for detecting a position of the movable body in an optical axis direction;
a sensing magnet disposed in the first groove of the movable body at a position corresponding to the position sensor;
a first coil and a driving magnet that oppose each other in a direction perpendicular to the optical axis direction to move the movable body in the optical axis direction; and
A stationary body having a second groove in which the position sensor is disposed at a position corresponding to the sensing magnet;
At least one surface of the sensing magnet is spaced apart from an inner surface of the first groove,
A camera module wherein an adhesive is disposed between the inner surface of the first groove and the at least one surface of the sensing magnet. 19. The method of claim 18, wherein the fixture
A camera module including a housing member supporting the driving magnet and accommodating the movable body so as to be movable in the optical axis direction. cover member;
a bobbin disposed within the cover member and including an outer circumferential surface and a receiving groove formed on the outer circumferential surface;
a position detector for detecting a position of the bobbin in an optical axis direction;
a sensing magnet disposed in the receiving groove of the bobbin at a position corresponding to the position sensor; and
a first coil disposed on the outer circumferential surface of the bobbin; and
A driving magnet facing the first coil,
The sensing magnet is disposed in the receiving groove of the bobbin,
The depth of the receiving groove of the bobbin is greater than the thickness of the sensing magnet,
The sensing magnet is disposed between the accommodating groove of the bobbin and the first coil, and is spaced apart from at least a part of the accommodating groove of the bobbin or the first coil. 21 . The camera module of claim 20 , wherein the sensing magnet is spaced apart from a bottom surface or a side surface of the receiving groove of the bobbin. 21. The method of claim 20, wherein the sensing magnet comprises a surface spaced apart from the inner surface of the receiving groove and facing the inner surface of the receiving groove,
At least a portion of the adhesive is disposed between the one surface of the sensing magnet and the inner surface of the receiving groove. The camera module according to claim 1 or 20, wherein the accommodating groove includes a surface parallel to a partial surface of the first coil disposed on the accommodating groove. The camera module according to claim 1 or 20, wherein the accommodating groove is disposed adjacent to a corner of the cover member.

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