KR20200073096A - Apparatus for auto focus - Google Patents

Abstract

According to the present invention, provided is an automatic focus controlling device, which comprises: a carrier mounted with a lens and linearly moving in an optical axis direction; a housing accommodating the carrier; a driving unit assembly provided in the housing and moving the carrier in the optical axis direction; and a ball positioned between the carrier and the housing and facing the carrier and the housing. At least one of a portion of the carrier to which the ball is faced or a portion of the housing to which the ball is faced is made of a metal material.

Description

Automatic focus control device {APPARATUS FOR AUTO FOCUS}

The present invention relates to an automatic focus adjustment device, and more particularly, to an automatic focus adjustment device with improved structure for guiding a ball and the like.

As the hardware technology for image processing advances and the user needs for image shooting increase, autofocus (AF, Auto Focus), hands on camera modules mounted on mobile terminals such as mobile phones and smartphones, as well as independent camera devices Functions such as image stabilization (OIS) have been implemented.

The autofocus (autofocus) function allows the lens or the assembly provided with the lens to move linearly in the optical axis direction to adjust the focal length with the subject, thereby creating a clear image in the image sensor (CMOS, CCD, etc.) provided at the rear of the lens. It means the function to be possible.

There are several ways to implement the autofocus function. As a representative method, a magnet is installed on an AF carrier (or moving object), a coil is installed on a fixed body (housing, or other type of carrier, etc.), and suitable for the coil. A method of moving the moving body in the direction of the optical axis by generating magnetic force in the coil (equipped in the fixed body) and the magnet (equipped in the movable body) by the power applied to the coil in size.

In addition, recently, a device or an actuator having an integrated AF and OIS function is used. In this case, the OIS carrier on which the lens is mounted is moved in the X-axis or/and Y-axis direction perpendicular to the optical axis within the AF carrier. The structure is implemented integrally with the AF structure described above. According to the embodiment, there is also a structure in which a lens is mounted on the AF carrier and the OIS carrier provided outside the AF carrier moves in a direction perpendicular to the optical axis direction.

In order to improve the behavior characteristics of the AF carrier moving in the optical axis direction, a device in which only the AF-only function or the AF and OIS functions are implemented is the same as the optical axis between the AF carrier (moving body) and the housing (fixing body). A structure having balls interposed in directions is applied.

This structure allows the proper separation distance between the moving body and the fixed body to be maintained continuously, and minimizes the frictional force through the moving and rolling of the ball itself and point contact with the ball, thereby reducing the AF carrier. Can move more flexibly and accurately in the direction of the optical axis.

Typically, in the conventional device, the ball is made of a metal material, whereas the AF carrier that contacts the ball and moves in the optical axis and provides a physical space for moving the AF carrier, and the housing that contacts the ball is made of plastic.

As described above, since the physical configuration of the ball and the ball are made of different materials, the parts that come into contact with the ball in the AF carrier and the housing due to differences in stiffness or hardness between the different materials (hereinafter referred to as the'guide support part') Wear tends to occur, and the more frequent use, the faster this wear phenomenon.

When a wear phenomenon occurs in the guide support portion as described above, since the ball does not precisely move linearly in the optical axis direction, the horizontality of the AF carrier physically touching the ball and moving in the optical axis direction is impaired, resulting in poor tilt This occurs, and such a tilt failure causes a deterioration of the autofocus function.

In addition, when a foreign substance such as plastic particles detached from the guide support portion due to abrasion occurs, this also acts as a factor that interferes with the linear guiding of the ball.

Furthermore, when external shaking or impact occurs, the metal ball having a relatively strong stiffness or high hardness transmits the impact to the guide support portion having a relatively weak to low hardness, and the ball is considerably smaller. Because of the diameter, these impacts can easily cause damage to local areas.

On the other hand, the housing is configured to accommodate a carrier and is provided with a drive unit made of electrical and electronic components, and most of the drive unit is coupled to the housing through processes such as adhesive application, heat curing, and cooling.

When the drive units are semi-assembled to the base frame through adhesive application, etc., they are separated from the manufacturing process line and moved to another process line or space for thermal curing and cooling of the applied adhesive, and a predetermined time for curing and cooling the adhesive ( After 40 minutes to 80 minutes), it is necessary to return to the manufacturing process line, and then perform the subsequent process.

Therefore, according to the prior art, since the process line is forced to be dualized, the process efficiency is lowered and the subsequent process must be stopped during the time for which the heat curing and cooling process is completed, so that the process time is prolonged. .

In addition, according to the prior art, since the drive unit made of electrical, electronic components, and metal yoke is bonded to the housing made of plastic by adhesive, the adhesive efficiency is low in that it is a mutual bonding of dissimilar materials. In addition, problems may arise in product reliability such as easily detached joints due to external impact.

The present invention has been devised to solve the above-mentioned problems in the background as described above, and by implementing a portion of the carrier or housing that the ball enters into a metal material corresponding to the ball, the wear and damage phenomenon according to the heterogeneous material is fundamentally By preventing, it is possible to realize the linear mobility of the AF carrier more precisely, as well as to provide an autofocus control device capable of sufficiently extending the service life.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by embodiments of the present invention. In addition, the objects and advantages of the present invention can be realized by a combination of the configuration and the configuration shown in the claims.

The autofocus control device of the present invention for achieving the above object is a lens is mounted and a carrier that moves linearly in the optical axis direction; A housing accommodating the carrier; A driving unit assembly provided in the housing and moving the carrier in an optical axis direction; And a ball positioned between the carrier and the housing and adjoining the carrier and the housing. In this case, at least one of a part of the carrier that the ball adjoins or the part of the housing adjoining the ball is made of metal. It is configured to be made of.

In addition, the carrier of the present invention is made of a metal material and may further include a first guide having a shape extending along the optical axis direction, in which case the ball may be configured to abut the first guide.

Here, the carrier of the present invention is preferably formed integrally with the first guide is inserted.

According to the embodiment, the housing of the present invention is made of a metal material and may further include a second guide having a shape extending along the optical axis direction, in which case the ball may be configured to adjoin the second guide. .

Here, the housing of the present invention is preferably molded integrally by inserting the second guide.

More preferably, the present invention may further include a support plate made of a metal that is coupled to the driving unit assembly and coupled to the housing.

Here, the support plate of the present invention is coupled to the drive unit assembly, the body portion is formed with an opening for exposing the drive assembly in the carrier direction; And it may include a guide portion extending in the lateral direction from the body portion, in this case the ball may be configured to abut the guide portion.

Furthermore, the guide portion may have a bent shape so that a part of the ball is accommodated, and the housing of the present invention is preferably formed integrally by inserting the support plate.

According to a preferred embodiment of the present invention, the carrier or the housing part that is in contact with the ball is implemented with a metal material that is the same material as the ball, thereby preventing the phenomenon caused by wear, damage, damage, etc. due to mutual physical contact of different materials can do.

Furthermore, it is possible to minimize the occurrence of tilt of the AF carrier, thereby further improving precision driving of the autofocus function, and also providing an effect of further extending the service life of the autofocus control device through enhancement of durability.

In addition, according to another embodiment of the present invention, when a drive unit assembly providing a driving force to the AF carrier is coupled to the housing by providing a support plate made of metal to the housing by a method such as insert injection, by a method such as welding. The support plate can be coupled to the housing.

As described above, the present invention can omit processes such as adhesive application, adhesive curing, and cooling as a whole by essentially improving the bonding method, thereby unifying the process line and dramatically improving process efficiency such as shorter process time. have.

Furthermore, in the case of the present invention, by utilizing a part of the support plate made of a metal material as a guide structure for adjoining the ball, it is possible to simultaneously provide synergistic effects for improving process efficiency and improving driving performance of the AF carrier.

The following drawings attached to this specification are intended to illustrate preferred embodiments of the present invention, and serve to more effectively understand the technical spirit of the present invention together with the detailed description of the invention described below, and thus the present invention is described in these drawings. It should not be interpreted as being limited to the matter.
1 is a view showing the configuration of an automatic focus adjustment device according to an embodiment of the present invention,
2 is a view showing a second guide and the like according to a preferred embodiment of the present invention,
3 is a view showing a first guide and a second guide according to an embodiment of the present invention,
4 is a view showing the configuration of an automatic focus adjustment device according to another preferred embodiment of the present invention,
5 is a view showing a state in which the drive assembly of the present invention shown in Figure 4 is coupled to the housing.
6 is a view showing a detailed configuration of the support plate 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. Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to ordinary or lexical meanings, and the inventor appropriately explains the concept of terms to explain his or her invention in the best way. Based on the principle that it can be defined, it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

Therefore, the configuration shown in the embodiments and drawings described in this specification is only one of the most preferred embodiments of the present invention and does not represent all of the technical spirit of the present invention, and various equivalents that can replace them at the time of this application It should be understood that there may be water and variations.

1 is a view showing the configuration of an automatic focus adjustment device (hereinafter referred to as'AF device') 100 according to an exemplary embodiment of the present invention.

As shown in FIG. 1, the AF device 100 of the present invention includes a case 110, a carrier 120, a housing 130, a driving unit assembly 170, a driving magnet 122, a sensing magnet 127, and a support It may be configured to include a plate 133.

The lens or lens assembly (not shown) is mounted on the carrier 120 of the present invention, so that the carrier 120 and its physical movement together, the lens or lens as the carrier 120 moves in the optical axis direction (Z axis direction) The assembly also moves in the optical axis direction, and through this movement, the distance to an image sensor (not shown) such as CCD or CMOS is adjusted to realize the autofocus function.

Of course, the AF device 100 of the present invention is applicable to both a device in which the AF function is implemented alone, and a device in which AF and OIS are integrated. In the following description, the configuration of the present invention will be described in detail based on an embodiment of a device in which the AF function is implemented alone.

The housing 130 of the present invention has a configuration corresponding to the carrier 120, and if the carrier 120 is a moving object for AF driving, the housing 130 corresponds to a fixed body from a relative viewpoint.

The housing 130 is a configuration that accommodates the carrier 120 and provides an inner space through which the carrier 120 moves, and the drive unit assembly 170 that moves the carrier 120 in the optical axis direction is the housing 130 It may be provided in.

The driving unit assembly 170 can be applied to various applications such as a shape memory alloy (SMA), a piezoelectric element, and a micro electromechanical system (MEMS) if the carrier 120 can be moved in the optical axis direction. One, it is desirable to implement in the form of applying the magnetic force generated between the magnet and the coil in consideration of efficiency such as power consumption, noise suppression, space utilization, linear movement characteristics, and precise control.

The driving unit assembly 170 according to an exemplary embodiment of the present invention may specifically include a driving coil 172, a circuit board 173, a yoke 175, and a driver 177.

When the power of the appropriate size and direction is applied from the outside, the driving coil 172 generates a magnetic force of the corresponding size and direction in the driving magnet 122 to cause the carrier 120 provided with the driving magnet 122 in the optical axis direction. It performs the function of moving.

Hall sensor (not shown) is a configuration that detects the current position of the lens (specifically, a magnet provided in the carrier 120) using a hall effect, and when the current position of the lens is sensed, an electrical signal corresponding thereto To the driver 177 of the present invention.

The driver 177 controls the power of the appropriate size and direction to be applied to the driving coil 172 by using the signal of the input Hall sensor, and feedback control of the correct position of the lens based on the optical axis direction through such cyclic control To implement the autofocus function.

The Hall sensor may be configured to sense the magnetic force of the driving magnet 122 and sense the position of the carrier 120 in the magnitude and direction of the sensed magnetic force, as well as to the carrier 120 in order to improve the efficiency of detection, etc. It may be configured to sense the magnetic force of the sensing magnet 127 is provided separately to sense the position of the carrier 120.

The hall sensor may be implemented as an independent component, but may be implemented in the form of a single chip together with the driver 177 through a system on chip (SOC) as illustrated in the drawing.

As shown in FIG. 1, a plurality of balls 140 arranged in a direction corresponding to an optical axis direction may be positioned between the carrier 120 and the housing 130, and the plurality of balls 140 may The carrier 120 and the housing 130 are spaced apart as much as corresponding to the diameter of the ball 140.

The carrier 130 is provided with a carrier (130) so that the carrier 120 and the housing 130 maintain a proper distance and the point contact or line contact to the ball of the carrier 120 is continuously maintained. A driving magnet 122 provided in the 120) and a yoke 175 made of a metal material for generating an attraction force may be provided.

2 is a view showing a second guide 131 and the like according to a preferred embodiment of the present invention, Figure 3 is a first guide 121 and the second guide 131 according to an embodiment of the present invention It is a drawing shown.

The carrier 120 and the housing 130 face each other with the ball 140 interposed therebetween, and each of the carrier 120 and the housing 130 guides the balls 140 and the guide structures 125 and 131. It includes.

In the case of a conventional device, such a guide structure is formed at an appropriate position of the carrier or housing in a process in which the carrier or housing is molded by a method such as plastic injection through appropriate design.

Therefore, in the case of the conventional device, since the part of the carrier and the housing that is in contact with the ball is made of a plastic material different from the ball 140 made of a metal material, the above-described problem occurs.

In the present invention, in order to effectively solve this problem, at least one of a portion that contacts the ball 140 in the carrier 120 or a portion that contacts the ball 140 in the housing 130 is made of a metal material.

According to the embodiment, the physical structure to which the ball 140 is guided is molded to the carrier 120 or the housing 130, and the guide member having a shape made of a metal material and extending along the optical axis direction is coupled to the physical structure It can be configured as much as possible. In this case, the guide member is preferably implemented with a metal material having a specification (rigidity and hardness, etc.) corresponding to the material of the ball 140.

In the following description, a guide member provided in a portion of the carrier 120 that is in contact with the ball 140 is referred to as a first guide 121, and a guide member provided in a portion of the housing 130 that is in contact with the ball 140. Is referred to as a second guide 131.

The first guide 121 or the second guide 131 may be embodied in a plate shape of a bent shape as illustrated in FIGS. 2 and 3, so that external departure of the ball 140 can be effectively prevented. It is preferable that one of the one guide 121 or the second guide 131 is bent so that a space is formed inside, and the other is bent so that a space is formed outside.

The carrier 120 or the housing 130 is usually made of a plastic material such as LCP (Liquid Crystal Polymer), PC, etc., and may be molded through an injection process. The first guide 121 or the second guide 131 made of a metal material may be provided in a manner that is bonded to the carrier 120 or the housing 130, but the first guide ( 121) and each of the second guides 131 are preferably formed integrally with the carrier 120 or the housing 130 by a method such as insert injection.

In addition, both the first guide 121 and the second guide 131 may be provided on the carrier 120 and the housing 130, but depending on the embodiment, only one of them may be provided on the carrier 120 or the housing 130. Of course, it may be provided.

The first guide 121 and the second guide 131 may be preferably formed in a groove line by a selected combination of V-shape or U-shape cross-sections in order to reduce friction and promote linear mobility. However, if the linear movement of the carrier 120 can be guided, the first guide 121 and the second guide 131 may be implemented in various shapes, including shapes that correspond to each other, such as concave or convex.

In addition, although the first guide 121 and the second guide 131 are illustrated in the drawing, two types are arranged side by side (based on the Y axis) on the same surface in the form of facing each other, but this is only one embodiment, and the carrier If the structure or shape to guide the movement of the optical axis in 120 is guided, it may be provided in different faces depending on the characteristics or physical structure of the device, and may also be implemented in a form that does not face each other.

4 is a view showing the configuration of the AF device 100 according to another preferred embodiment of the present invention, Figure 5 is a drive unit assembly 170 of the present invention shown in Figure 4 is coupled to the housing 130 It is a diagram showing.

Unlike the embodiment illustrated in FIG. 1, the embodiment illustrated in FIG. 4 is an embodiment in which the sensing magnet 127 is provided on the same surface as the driving magnet 122, and the driving unit assembly 170 also includes such a magnet 122 , 127) corresponds to an embodiment having a shape characteristic corresponding to the structure.

As illustrated in FIG. 4, the first guide 121 may have a V-shaped cross section and may be configured to have an extended shape based on the optical axis direction (Z-axis), and as described above, the first guide ( 121) may be provided on the carrier 120 by a method such as adhesion, or may be integrally provided on the carrier 120 by insert injection or the like.

The support plate 133 is a configuration that forms one side of the housing 130 in a direction corresponding to the optical axis direction, and is susceptible to be coupled with the driving unit assembly 170 through a metal-to-metal coupling method such as welding. It is preferably made of a metal material such as.

As described above, it is more preferable that the support plate 133 is also configured to be integrally molded with the housing 130 through an insert injection method or the like so as to improve durability and improve the efficiency of an assembly process.

4 and 5, the driving coil 172 and the driver 177 are mounted on the circuit board 173, and the yoke 175 is bonded to the rear surface of the circuit board 173, so that the driving unit assembly of the present invention ( 170) may be manufactured in advance as one component assembly.

In this case, the yoke 175 made of a metal material and the support plate 133 of the present invention can be mutually coupled by a metal-to-metal coupling method such as welding, so that the drive unit assembly 170 is attached to the housing 130. The joining process efficiency can be further increased.

Therefore, the process of bonding the drive unit assembly 170 to the housing 130 through processes such as conventional adhesive application, curing, and cooling can be entirely omitted, thereby further improving process efficiency.

6 is a view showing a detailed configuration of the support plate 133 according to an embodiment of the present invention.

As shown in FIG. 6, the support plate 133 of the present invention may include a body part 1331, an opening part 1332, and guide parts 1334 and 1335.

The body part 1331 is a structure corresponding to a basic frame that is joined to the driving part assembly 170 and physically supports the driving part assembly 170 as described above.

The first opening 1332-1 constituting the opening portion 1332 exposes the driving coil 172 of the driving unit assembly 170 in the direction of the driving magnet 122 provided in the carrier 120, and the second opening ( 1332-2) exposes the driver 177 with a built-in Hall sensor in the direction of the sensing magnet 127 provided in the carrier 120.

The positions or shapes of the first opening 1332-1 and the second opening 1332-2 may be implemented differently from the shapes shown in the drawings according to types, arrangements, and positions of components constituting the driving unit assembly 170. Of course, the first opening 1332-1 and the second opening 1332-2 may be embodied as one opening depending on the embodiment.

Through the first opening 1332-1, the magnetic force of the driving coil 172 can be more effectively transmitted to the driving magnet 122, and the sensor (drive 177) through the second opening 1332-2. Built-in) can sense the magnetic force of the sensing magnet 127 more precisely.

The guide portions 1334 and 1335 of the support plate 133 are formed to extend to one side or both sides based on the body portion 1331, and correspond to a configuration that enters into contact with the ball 140 as illustrated in FIG. 6.

One or more of the guide parts 1334 and 1335 may be bent in a shape in which a portion of the ball 140 is acceptable so that guiding and support of the ball 140 may be more effectively implemented as illustrated in FIG. 6.

When the support plate 133 is implemented as described above, the driving unit assembly 170 may be joined by a metal-to-metal welding method to improve process efficiency, as well as the ball 140 as described above. It is possible to simultaneously perform a function for the second guide 131 to entertain.

Although the present invention has been described above by way of limited examples and drawings, the present invention is not limited by this, and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the equal scope of the claims.

In the above description of the present invention, since the modifiers such as first and second are only terms of a tool concept used to relatively distinguish components between each other, they are used to indicate a specific order, priority, and the like. It should be interpreted as not being a term.

The accompanying drawings and the like for the description of the present invention and the embodiments thereof may be shown in a somewhat exaggerated form in order to emphasize or emphasize the technical content of the present invention, but the above-described content and matters shown in the drawings In view of this, it should be interpreted that it is obvious that various types of modification examples may be possible at the level of those skilled in the art.

100: automatic focus adjustment device
110: case 120: carrier
121: first guide 122: driving magnet
125: Guide structure 127: Sensing magnet
130: housing 131: second guide
133: support plate
1331: body portion 1332: opening portion
1332-1, 1332-2: 1st and 2nd opening 1334, 1335: Guide part
140: ball 170: drive assembly
172: driving coil 173: circuit board (FPCB)
175: York 177: Driver (Hall sensor)

Claims (9)

A carrier on which the lens is mounted and linearly moves in the optical axis direction;
A housing accommodating the carrier;
A driving unit assembly provided in the housing and moving the carrier in an optical axis direction; And
A ball positioned between the carrier and the housing and adjoining the carrier and the housing,
Automatic focusing device, characterized in that at least one of the portion of the ball in the carrier or the portion of the ball in the housing is made of a metal material. The method of claim 1, wherein the carrier,
Made of a metal material and further includes a first guide having a shape extending along the optical axis direction,
The ball is an automatic focus control device, characterized in that the first guide. According to claim 2, The carrier,
Automatic focus adjustment device, characterized in that the first guide is inserted and is integrally molded. According to claim 1, The housing,
Made of a metal material and further includes a second guide having a shape extending along the optical axis direction,
The ball is an automatic focusing device, characterized in that the second guide. The method of claim 4, wherein the housing,
Automatic focus adjustment device characterized in that the second guide is inserted and is integrally molded. According to claim 1,
The drive unit assembly is coupled, the automatic focus adjustment device further comprises a support plate of a metal material coupled to the housing. The method of claim 6, wherein the support plate,
A body part in which the driving part assembly is coupled and an opening part exposing the driving part assembly in the carrier direction is formed; And
It includes a guide portion extending in the lateral direction from the body portion,
The ball is an automatic focus adjustment device, characterized in that the abutting the guide portion. The method of claim 7, wherein the guide portion,
Automatic focusing device, characterized in that a part of the ball has a bent shape to be acceptable. The method of claim 6, wherein the housing,
Automatic focusing device, characterized in that the support plate is inserted and molded integrally.

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