KR20210061989A - Actuator for actuating lens - Google Patents

Abstract

Provided is an actuator. An embodiment of the present invention comprises: a cover can forming an appearance; a base fastened to the lower side of the cover can; a mover including a bobbin provided on an upper side of the base and fixing a lens unit and a coil unit provided on an outer surface of the bobbin; and a stator including a magnet part provided to face the outside of the coil unit and a housing for fixing the magnet part, wherein the housing comprises a magnet part fastening hole formed in a shape corresponding to the magnet part on a side surface; and a first bonding hole formed on a lower surface of the magnet part fastening hole and into which an adhesive for fixing the magnet part to the magnet part fastening hole.

Description

Lens-driven actuator {ACTUATOR FOR ACTUATING LENS}

An embodiment of the present invention relates to an actuator having an improved structure, a camera module provided with the actuator, and a mobile phone.

As the spread of various portable terminals has become widespread and the wireless Internet service is commercialized, the demands of consumers related to portable terminals are also diversifying. Accordingly, various types of additional devices are installed in the portable terminals.

Among them, an actuator is a representative that can capture a subject as a photo or video, store the image data, and edit and transmit it as necessary.

BACKGROUND ART In recent years, the demand for small-sized actuators is increasing for various multimedia fields such as notebook personal computers, camera phones, PDAs, smart phones, toys, etc., and also for image input devices such as information terminals of surveillance cameras and video tape recorders.

In particular, cameras for mobile phones are trending toward higher resolution and miniaturization in accordance with the rapid change in the smartphone market, and in order to reduce the price, it is necessary to shorten the assembly process and reduce the number of personnel.

In the conventional actuator assembly process, the upper assembly process of fastening the housing bonded with the magnet to the cover can, the lower assembly process of fastening the bobbin wound with the coil to the base, and fastening the cover can and the base are completed. do.

That is, in assembling the actuator, it must undergo at least three processes: a bonding process between a magnet and a housing, a bonding process between a housing and a cover can, and a bonding process between a cover can and a base. Here, the bonding process is performed using an adhesive such as epoxy.

This complex assembly process has the following problems.

First, when the adhesive applied to the upper assembly is left for a long time to bond the upper assembly and the lower assembly, there may be a problem that the adhesive strength is reduced. Such a decrease in adhesion may result in a decrease in the performance of the actuator, and may cause an increase in performance defects such as hysteresis due to separation of the resin contained in the adhesive.

Second, since the adhesive application operation must be performed at least two or three times, the process cost that requires additional equipment and workers for bonding increases.

Third, as the number of bonding operations increases, it is difficult to automate the assembly process.

The embodiment is to provide an actuator that is improved compared to the prior art in terms of reducing the tolerance of an assembly process, implementing automation, and cost of a process.

An embodiment is a mover comprising a cover can forming an exterior, a base fastened to a lower side of the cover can, a bobbin provided on the upper side of the base and fixing a lens unit, and a coil unit provided on an outer surface of the bobbin And, a stator including a magnet part provided to face the outside of the coil part and a housing for fixing the magnet part, the housing having a magnet part fastening hole formed in a shape corresponding to the magnet part at a side thereof, It provides an actuator including two or more first bonding holes formed on a lower surface of the magnet part fastening hole and into which an adhesive for fixing the magnet part to the magnet part fastening hole is introduced.

In addition, the first bonding hole may be opened toward the outside of the housing and may be formed to be closed by an inner circumferential surface of the cover can.

In addition, the housing is formed in a hexahedral shape with open upper and lower sides, and the magnet part may be provided on four sides of the housing.

In addition, the housing may further include a second bonding hole formed between the first bonding hole and into which an adhesive for fixing the cover can and the base is introduced.

In addition, the second bonding hole may be opened toward the outside of the housing and may be formed to be closed by an inner circumferential surface of the cover can.

In addition, the housing may be formed in a hexahedral shape with open upper and lower sides, and the second bonding holes may be respectively formed at corners of the housing.

In addition, the cover can may be formed of a metal material.

In addition, a lower end of the cover can may have at least one fastening piece extending on each surface, and a fastening groove into which the fastening piece is inserted may be formed in the base.

In addition, the stator may include a yoke portion fixing the magnet portion.

In addition, the yoke portion may be implemented as the cover can.

In addition, an upper surface of the cover can has an opening through which the lens of the moving part is exposed, an inner yoke bent inside the cover can is formed in the opening, and the inner yoke is formed on the bobbin and the bobbin. A groove formed on an outer peripheral surface may be formed so as to be positioned between the wound coil parts.

Meanwhile, an embodiment of the present invention may be implemented as a camera module or a mobile phone including the actuator.

According to an embodiment of the present invention, by improving the structure of the housing, an actuator that shortens assembly tolerances, improves productivity, reduces labor costs due to automation, and improves reliability due to improved adhesion.

1 is a perspective view of an actuator according to an embodiment of the present invention.
2 is an exploded perspective view of an actuator according to an embodiment of the present invention.
3 is a perspective view of a housing according to an embodiment of the present invention.
4 is a rear view of a housing according to an embodiment of the present invention.
Figure 5 is a rear view of the coupling of the housing, the cover can and the lower spring according to an embodiment of the present invention.

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

Unless otherwise defined, all terms in this specification are the same as the general meanings of terms understood by those skilled in the art, and if terms used in the present specification conflict with the general meanings of the terms, the definitions used in the present specification are applied. .

However, the invention to be described below is only for describing an embodiment of the present invention, not for limiting the scope of the present invention, and reference numerals used identically throughout the specification denote the same elements.

Hereinafter, an actuator of an embodiment will be described in detail with reference to the drawings.

1 is a combined perspective view of an actuator according to an embodiment of the present invention, FIG. 2 is an exploded perspective view of an actuator according to an embodiment of the present invention, and FIG. 3 is a perspective view of a housing 320 according to an embodiment of the present invention, 4 is a rear view of a housing 320 according to an embodiment of the present invention, and FIG. 5 is a rear view of a combination of the housing 320, the cover can 100, and the lower spring 151 according to the embodiment of the present invention. .

1 and 2, the actuator according to the embodiment may largely include a mover 200, a stator 300, a base 400, and an elastic unit 500.

The actuator according to the embodiment may further include a cover can 100, and the cover can 100 accommodates the mover 200, the stator 300 and the elastic unit 500, and provides an external appearance of the actuator. Can be formed. In addition, the cover can 100 is mounted on the base 400 in close contact with the side surface of the base 400 to be described later, and protects internal components from external impacts and prevents penetration of external contaminants. Have.

In an embodiment, in order for the cover can 100 to be fastened to the base 400, the lower end of the cover can 100 may have at least one fastening piece 110 extending on each surface thereof, and the base A fastening groove 410 into which the fastening piece 110 is inserted may be formed in 400 to implement a more robust sealing function and a fastening function.

In addition, the cover can 100 must also perform a function of protecting components of the actuator from external radio wave interference generated by a mobile phone or the like. Therefore, it is preferable that the cover can 100 is formed of a metal material. The cover can 100 may be implemented as a yoke part itself, or may be fixed by molding the yoke part inside. In an embodiment, an upper surface of the cover can 100 is formed with an opening 120 through which the lens of the lens unit 10 accommodated in the mover 200 is exposed, and the cover can (100) The inner yoke 130 formed bent inward may be formed. The inner yoke 130 may be located in the groove 215 formed in the bobbin 210 to be described later. The inner yoke 130 is positioned in the groove 215 of the bobbin 210 to prevent rotation of the bobbin 210 in the direction of the optical axis and to concentrate magnetic flux.

On the other hand, the mover 200 is provided on the upper side of the base 400 and includes a bobbin 210 for fixing the lens unit 10 and a coil unit 220 provided on the outer surface of the bobbin 210 do.

The mover 200 fixes the lens unit 10 so as to be positioned therein, and the mover 200 including the lens unit 10 moves to adjust the focus of the image.

Here, adjusting the focus of the image means an AF (Auto Focusing) function that moves the lens unit 10 in the z-axis direction, which is the optical axis direction, for near or far focusing of the subject, or the z It may mean an OIS (Optical Image Stabilization) function that moves the lens unit 10 in the x- and y-axis directions perpendicular to the axial direction, or it may mean a function capable of simultaneously performing the AF function and the OIS function. .

That is, the actuator unit 100 may be implemented as an A.F (Auto Focusing) type, a ㄸ or an OIS (Optical Image Stabilization) type, or an A.F type and an OIS type simultaneously implemented.

The lens unit 10 may be a lens barrel including at least one lens, but is not limited thereto, and any holder structure capable of supporting the lens may be included. In the embodiment, the case where the lens unit 10 is a lens barrel will be described as an example. The lens unit 10 is installed above the base 400 to be described later, and is disposed at a position corresponding to an image sensor to be described later. The lens unit 10 includes one or more lenses (not shown). The lens unit 10 may be screw-coupled to the inner circumferential surface of the bobbin 210, which will be described later, or screwlessly coupled using an adhesive 600 or the like.

Specifically, the bobbin 210 may have a first winding guide part 211 and a second winding guide part 212 for guiding the winding of the coil part 220 to be described later on the upper and lower ends of the outer surface. have. The first winding guide part 211 and the second winding guide part 212 may be integrally formed with the outer surface of the bobbin 210, and may be continuously formed along the outer surface of the bobbin 210 or may be It can be formed spaced apart at intervals. In addition, either the first winding guide part 211 or the second winding guide part 212 may be formed, or a pre-wound coil part may be fixed to the bobbin without a separate winding guide part.

In addition, the upper side of the bobbin 210 is formed to protrude at a predetermined interval so that it can contact the upper side of the cover can 100 in case of an external impact, thereby absorbing an impact and guiding the upper spring 510. Stoppers 213 may be formed, and at least two or more of them may be formed. The stopper 213 may be integrally formed with the bobbin 210. In addition, the stopper 213 may be formed above the first winding guide part 211.

In addition, a lower fastening protrusion 214 to which a lower spring 520 provided to support the bobbin 210 from an upper side of the base 400 to be described later may be formed on the lower side of the bobbin 210. have.

In addition, in the bobbin 210, the inner yoke 130 of the cover can 100, which will be described later, is located between the bobbin 210 and the coil part 220 wound around the bobbin. ) May be further included.

The coil unit 220 may be guided by the first winding guide unit 211 and the second winding guide unit 212 to be wound on the outer surface of the bobbin 210, but four individual coils are provided with the bobbin ( 210) may be disposed at intervals of 90°. In addition, the pre-wound coil unit may be fixed to the outer surface of the bobbin. When viewed from a plan view, the shape of the coil part may be a circular shape, a polygonal shape, a polygonal shape including a circular shape, and the like. The coil unit 220 forms an electromagnetic field by receiving power applied from a printed circuit board to be described later.

The stator 300 may include a magnet part 310 provided to face the outside of the coil part 220 and a housing 320 for fixing the magnet part 310.

As shown, in the case of the former auto-focusing (AF) type, the actuator unit is provided with a magnet part 310 provided on the side of the housing 320 to be described later, and the outer circumferential surface of the body of the bobbin 210, and the magnet part It includes a coil unit 220 provided at a position corresponding to the inner surface of (310). In addition, a yoke portion for fixing the magnet portion 310 may be included, and in an embodiment, the yoke portion may be a cover can.

Here, the yoke portion may be implemented as the cover can 100 or, although not shown, may be implemented as an additional component.

In the case of the latter OIS (Optical Image Stabilization) type, which is not shown, although not shown, an OIS coil unit (not shown) provided in the base 400 to be described later so that it is positioned to correspond to the lower side of the magnet unit 310 And, the OIS coil unit may further include a substrate disposed on an upper surface of the base 400 to receive power, and the substrate may be an FPCB (not shown). The base 400 or the substrate may further include a Hall sensor unit (not shown) provided at a position corresponding to the magnet unit 310. Of course, the Hall sensor unit may be electrically connected to the substrate, and may be connected to an external power source or an OIS control unit of the camera module to transmit a signal to the OIS drive.

The coil unit 220 is fixed to the bobbin and moves the bobbin up and down to move the lens unit 10 up and down in the optical axis direction, and the OIS coil unit moves the lens unit 10 in a direction perpendicular to the optical axis direction. Can be moved to.

Here, the coil unit 220 may receive power from a printed circuit board, and the OIS coil unit may be disposed on a substrate provided above the base 400 (not shown) to receive power by the substrate. On the other hand, when considering miniaturization of the actuator, specifically, lowering the height in the z-axis direction, which is the optical axis direction, the OIS coil unit may be formed as a patterned coil.

In the latter case of the OIS (Optical Image Stabilization) type, the Hall sensor unit is provided to sense the strength of the magnetic field according to the position of the magnet to detect the movement of the magnet unit 310, and is provided to precisely control the actuator. .

In addition, the Hall sensor unit is disposed in a straight line with the magnet unit 310 on the z-axis, and detects displacements in the x-axis and y-axis. This Hall sensor unit is provided adjacent to the OIS coil unit than the magnet unit 310, but considering that the strength of the magnetic field formed in the magnet is several hundred times greater than the strength of the electromagnetic field formed in the coil, the movement of the magnet unit 310 In sensing, the influence of the OIS coil is not considered. In addition, in the case of the OIS type, a separate second substrate is disposed on the upper surface of the housing so that the position of the housing 320 is supported with respect to the first substrate on which the Hall sensor is disposed, The substrate may be connected by a separate wire member or an elastic member such as a leaf spring, and the elastic member may be formed of a conductive material to transmit electrical signals to the AF coil or the OIS coil.

In addition, the actuator according to the embodiment of the present invention may further include an elastic unit (500).

The elastic unit 500 includes an upper spring 510 and a lower spring 520.

The upper spring 510 and the lower spring 520 may be formed of a plurality of springs disposed at respective corners of the housing 320, but a single plate is bent and cut as shown for production efficiency. It is preferably made of a leaf spring.

Accordingly, the upper spring 510 and the lower spring 520 have an approximately ring shape, and the inner periphery may be formed in a circular shape to correspond to the shape of the moving part 300, and the outer periphery of the housing 320 and the base It may be formed in a square shape so as to be supported by the shape of 400, and the inner and outer circumferential shape is not limited thereto, and various shapes can be changed.

The upper spring 510 is fastened to the upper surface of the housing 320 and the upper surface of the bobbin 210 to support the bobbin 210, and to provide a return force when the bobbin 210 moves upward, the housing 320 ) Is provided on the upper end. In addition, the upper spring 510 is disposed at the upper end of the housing 320 and protrudes a predetermined width in the inner circumferential direction from the opening formed at the upper end, and the protruding portion supports the upper end side of the moving part 300. .

At least one upper fastening hole 511 or an upper fastening groove is formed in the upper spring 510, and an upper fastening corresponding to the upper fastening hole 511 or the upper fastening groove is formed on the upper surface of the housing 320 The protrusion 321 may be formed.

On the other hand, the rim side of the lower spring 520 is disposed or supported on the upper surface of the base 400, and the inner circumferential side supports the lower end side of the moving part 300. The lower spring 520 may be provided with a lower fastening hole 521 or a lower fastening groove to support the lower side of the bobbin 210, and at this time, a fastening hole or a fastening protrusion coupled to the fastening groove at the lower side of the bobbin Can be formed. In addition, a terminal portion 522 that is bent toward the base 400 may be formed on one side of the lower spring 520, and the terminal portion 522 is a terminal hole 420 or a side surface formed in the base 400 to be described later. Alternatively, it may be electrically connected to a printed circuit board (not shown) through a method such as soldering by exposed coupling through a groove. Power applied to the terminal unit 522 may be connected to both ends of the coil wound on the bobbin 210 to transmit electrical signals.

3 and 4, the housing 320 is formed of an insulating material, and in consideration of productivity, it is preferable that it is formed as an injection product.

Specifically, the housing 320 may be formed in a shape corresponding to the inner surface of the cover can 100 forming the exterior of the actuator. In an embodiment, the housing 320 may be formed in a hexahedral shape corresponding to the shape of the cover can 100, and the upper and lower sides may be opened to surround the lens unit 10 and the mover 200.

In addition, the housing 320 may include a magnet part fastening hole 322 or a magnet part fastening groove formed in a shape corresponding to the magnet part 310 on a side surface. That is, in the illustrated magnet part 310, four magnets are formed in a rectangular shape, and the magnet part fastening hole 322 or the magnet part fastening groove may be formed in a rectangular shape corresponding to the four magnets. have.

In addition, the housing 320 is formed on the lower side of the magnet part fastening hole 322, and two adhesives 600 for fixing the magnet part 310 to the magnet part fastening hole 322 are introduced. The above first bonding hole 323 may be included. In the embodiment, since the magnet part 310 is composed of four magnets, four first bonding holes 323 are formed below the magnet part fastening hole 322. The first bonding hole 323 is formed from the lower side of the housing 320 to the magnet part fastening hole 322. Referring to FIG. 3, the first bonding hole 323 may be formed as a groove recessed from the outer surface of the housing 320. In this case, the first bonding hole 323 may be a first groove. Meanwhile, the second bonding hole 324 may be a second groove. Alternatively, the second bonding hole 324 may be referred to as a first groove and the first bonding hole 323 may be referred to as a second groove.

Referring to FIG. 5, the first bonding hole 323 more firmly fixes the magnet part 310 inserted into the magnet part fastening hole 322, and an appropriate amount of adhesive 600 can be used. Thus, as in the prior art, when the amount of the adhesive 600 is excessive or less, it may have an excellent effect in terms of reliability. Here, the first bonding hole 323 may be formed as a hole penetrating from the lower side of the housing 320 to the magnet part fastening hole 322 to fix the magnet part 310, but the illustrated As described above, it is open toward the outside of the housing 320 and may be formed to be closed by the inner circumferential surface of the cover can 100. In the latter case, not only bonding of the magnet part 310 and the magnet part fastening hole 322 when bonding to the first bonding hole 323 according to the embodiment, but also the housing 320 and the cover can 100 Bonding can be done, so it can be fixed more firmly.

In addition, the housing 320 is formed between the first bonding hole 323, the second bonding hole 324 through which the adhesive 600 for fixing the cover can 100 and the base 400 is introduced. It may include. The second bonding hole 324 according to the embodiment is opened toward the outside of the housing 320, like the first bonding hole 323, and is formed to be closed by the inner circumferential surface of the cover can 100. The adhesive 600 filled in the second bonding hole 324 bonds the cover can 100 and the housing 320 firmly, and is adhered to the upper side of the base 400 to securely fasten the actuator. Make it possible. Here, for a solid bonding with the base 400, the larger the application area of the adhesive 600 is, the more preferable. Accordingly, the second bonding holes 324 may be formed at corners of the housing 320 having a relatively large fastening area with the base 400. 2, the second bonding hole 324 of the housing 320 may be disposed at a position corresponding to the fixing protrusion 440 of the base 400 in the optical axis direction.

Meanwhile, the base 400 may be disposed under the housing 320. This base 400 may perform a sensor holder function that protects an image sensor (not shown) to be described later, and in this case, in order to position an IR filter (not shown), between the driving unit 100 and the printed circuit board It can be provided. In addition, depending on the design, the base may be formed without a sensor holder function.

In this case, the IR filter may be mounted on the hollow part 430 formed in the center of the base 400. The IR filter may be provided with an infrared filter (Infrared Ray Filter). In addition, the IR filter may be formed of, for example, a film material or a glass material, and an infrared blocking coating material may be disposed on a flat optical filter such as a cover glass for protecting an imaging surface or a cover glass.

In addition, the base 400 may be formed with two or more fixing protrusions 440 protruding from the upper edge to make an interview with the inner surface of the cover can 100, and the fixing protrusion 440 may be formed of the cover can ( It guides the fastening of 100) easily and at the same time makes it possible to secure a firm fixation after fastening. The fixing protrusion 440 may be a protrusion.

In addition, the base 400 may have a fastening groove 410 into which the fastening piece 110 of the cover can 100 is inserted. This fastening groove 410 is formed locally on the outer surface of the base 400 in a shape corresponding to the length of the fastening piece 110, or a predetermined lower portion of the cover can 100 including the fastening piece 110 It may be formed entirely on the outer surface of the base 400 so that a part can be inserted.

In addition, the actuator according to the embodiment of the present invention may be implemented as a camera module, and in this case may further include a printed circuit board, a filter, and an image sensor.

The printed circuit board may be disposed under the base 400. The printed circuit board has an image sensor (not shown) mounted in the center of the upper side, and various devices (not shown) for driving the actuator may be mounted. In addition, the printed circuit board is electrically connected to the aforementioned terminal unit 522 to apply power for driving the actuator unit 100 to be described later to the actuator unit 100.

The image sensor (not shown) may be mounted at the center of the upper side of the printed circuit board so that it can be positioned along the optical axis direction with at least one lens (not shown) accommodated in the lens unit 10. Such an image sensor converts an optical signal of an object incident through the lens into an electrical signal.

Meanwhile, the adhesive 600 may be implemented as a thermosetting epoxy or UV epoxy, and is cured by heat or UV exposure. Here, the thermosetting epoxy is a method of curing by applying heat directly or indirectly, and the UV (ultraviolet) epoxy is a method of curing by applying UV (ultraviolet) to the adhesive 600.

In an embodiment, the adhesive 600 may be an epoxy in which heat curing and UV (ultraviolet) curing can be mixed, and both thermal curing and UV (ultraviolet) curing are possible, so that the adhesive 600 may be an epoxy that can be cured by selecting any one of them. have. The adhesive 600 is not limited to the epoxy, and any material capable of bonding may be substituted.

In short, in the embodiment of the present invention, since the moving part, the driving part, and the housing are accommodated in the cover can, and the adhesive can be applied to the first bonding hole and the second bonding hole formed on the lower side of the housing in a single process, Productivity is improved due to a reduction in production equipment and personnel, and a reduction in separation of resin due to a long period of adhesive neglect has the advantage of improving reliability and durability due to rapid adhesion between component parts.

The actuator according to this embodiment may be implemented as a camera module, and may be provided in a mobile phone.

Above, by the above description, those skilled in the art will recognize that various changes and modifications can be made without departing from the technical spirit of the present invention, and the technical scope of the present invention is not limited to the contents described in the embodiments, but claims It should be determined according to the scope and the scope equivalent thereto.

100: cover can 200: mover
210: bobbin 220: coil unit
300: stator 310: magnet portion
320: housing 323: first bonding hole
324: second bonding hole 400: base
500: elastic unit 510: upper spring
520: lower spring 600: adhesive

Claims (1)

A cover can including an upper plate and a side plate extending downward from an outer circumference of the upper plate;
A bobbin disposed in the cover can;
A housing disposed between the bobbin and the cover can;
A base disposed under the bobbin and coupled to the side plate of the cover can;
A coil disposed on the bobbin;
A magnet disposed between the coil and the side plate of the cover can and facing the coil;
A lower spring connecting the bobbin and the base; And
An actuator comprising an adhesive bonding the housing and the cover can.

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