KR20220122676A - auto focus device - Google Patents

Abstract

The auto-focus control device according to the present invention includes a carrier on which a lens is mounted and linearly moving in the optical axis direction; a housing accommodating the carrier; a driving unit assembly provided in the housing and configured to move the carrier in an optical axis direction; and a ball positioned between the carrier and the housing and facing the carrier and the housing, wherein at least one of a portion of the carrier that the ball hits and a portion of the housing that the ball hits is made of a metal material. do it with

Description

auto focus device

The present invention relates to an automatic focus adjustment apparatus, and more particularly, to an automatic focus adjustment apparatus having an improved structure for guiding a ball.

As hardware technology for image processing develops and user needs for image shooting increase, autofocus (AF (Auto Focus), hand Functions such as optical image stabilization (OIS) are being implemented.

The autofocus (autofocus) function makes the lens or the lens-equipped assembly move linearly in the optical axis direction to adjust the focal length with the subject, thereby creating a clear image on the image sensor (CMOS, CCD, etc.) provided at the rear end of the lens. function to make it happen.

There are several ways to implement the autofocus function, and typical methods include installing a magnet in an AF carrier (or moving body), installing a coil in a fixed body (housing or other type of carrier, etc.), and installing an appropriate A method of moving the moving body in the optical axis direction by generating magnetic force in the coil (provided in the fixed body) and the magnet (provided in the moving body) by the power applied to the coil in the same size is exemplified.

In addition, recently, a device or actuator in which the AF and OIS functions are integrated has been used. In this case, the OIS carrier on which the lens is mounted is moved in the X-axis and/or Y-axis direction perpendicular to the optical axis inside the AF carrier. The structure is integrally implemented 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 a device in which only the AF alone function is implemented or in a conventional device in which both AF and OIS functions are implemented, the same optical axis is placed between the AF carrier (moving body) and the housing (fixed body) in order to improve the behavior characteristics of the AF carrier moving in the optical axis direction. A structure in which balls arranged in the direction are interposed is applied.

This structure allows the proper separation distance between the moving body and the fixed body to be continuously maintained, and by minimizing the frictional force through the moving, rolling, and point contact of the ball itself, the AF carrier can be moved more flexibly and accurately in the direction of the optical axis.

In general, in the conventional apparatus, the ball is made of a metal material, whereas the AF carrier that moves along the optical axis while interacting with the ball and the physical space in which the AF carrier moves are provided, and the housing that treats the ball is made of a plastic material.

In this way, the physical configuration of the ball and the ball are made of different materials, and the part that serves the ball in the AF carrier and the housing due to the difference in stiffness or hardness between the different materials (hereinafter referred to as the 'guide support part'). wear is easy to occur, and this wear phenomenon accelerates with frequent use.

When abrasion occurs in the guide support part as described above, the ball cannot move precisely linearly in the optical axis direction, so the horizontality of the AF carrier moving in the optical axis direction by physically treating the ball is disrupted, resulting in poor tilt occurs, and this tilt failure causes the performance of the auto focus function to deteriorate.

In addition, when foreign substances such as plastic particles detached from the guide support part due to abrasion phenomena etc. are generated, this also acts as a factor hindering the linear guiding of the ball.

Furthermore, when external shaking or impact occurs, the metal ball having relatively strong rigidity or high hardness transmits the shock as it is to the guide support part having relatively weak or low hardness, and furthermore, the ball is considerably small Because it has a diameter, such an impact can easily cause damage to a local area.

On the other hand, the housing is a configuration for accommodating the carrier and is provided with a driving unit composed of electric and electronic components. Most of these driving units are coupled to the housing through processes such as adhesive application, thermosetting, and cooling.

When the driving 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 ( After 40 to 80 minutes), it should be returned to the manufacturing process line again, and then the subsequent process should be performed.

Therefore, in the case of the prior art, since the process line is inevitably dualized, the process efficiency is lowered, and the subsequent process must be stopped during the time when the thermal curing and cooling processes are completed, so it can be said that the process time is long. .

In addition, in the case of the prior art, since the electric and electronic components and the driving unit made of a metal yoke are bonded to the plastic housing by an adhesive, the bonding efficiency is low in terms of mutual bonding of different materials, as well as external impact. There may be problems in product reliability, such as easy separation of the joined parts by the same.

The present invention was devised to solve the above-mentioned problems in the background as described above, and by realizing the part where the ball is treated in a carrier or housing with a metal material corresponding to the ball, wear and damage caused by different materials can be fundamentally prevented. It is an object of the present invention to provide an auto-focusing device capable of sufficiently extending the service life as well as being able to more precisely implement the linear mobility of the AF carrier by preventing it.

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

Autofocus control apparatus of the present invention for achieving the above object is a lens mounted carrier that moves linearly in the optical axis direction; a housing accommodating the carrier; a driving unit assembly provided in the housing and configured to move the carrier in an optical axis direction; and a ball positioned between the carrier and the housing and facing the carrier and the housing. In this case, at least one of a portion of the carrier facing the ball or a portion of the housing facing the ball is made of a metallic material. is configured to be

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

Here, it is preferable that the carrier of the present invention is integrally formed by inserting the first guide.

According to an embodiment, the housing of the present invention may further include a second guide made of a metal material and having a shape extending along the optical axis direction. In this case, the ball may be configured to treat the second guide. .

Here, it is preferable that the housing of the present invention is integrally formed by inserting the second guide.

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

Here, the support plate of the present invention includes: a body part to which the driving part assembly is coupled and an opening part for exposing the driving part assembly in the direction of the carrier is formed; and a guide portion extending in the lateral direction from the body portion, in which case the ball may be configured to treat the guide portion.

Furthermore, the guide part may have a bent shape to accommodate a portion of the ball, and it is preferable that the housing of the present invention is integrally formed by inserting the support plate.

According to a preferred embodiment of the present invention, the carrier or housing portion that treats the ball is implemented with a metal material that is the same material as the ball, thereby preventing abrasion, damage, breakage, etc. caused by mutual physical contact of dissimilar materials can do.

Furthermore, since it is possible to minimize the tilt of the AF carrier, it is possible to further improve the precise operation of the auto focus function, and to provide the effect of further extending the service life of the auto focus control device through the enhancement of durability.

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

As such, the present invention can omit the entire process such as adhesive application, adhesive curing, and cooling through the essential improvement of the bonding method, thereby unifying the process line and dramatically improving the process efficiency such as shortening the process time. have.

Furthermore, according to the present invention, by utilizing a part of the support plate made of a metal material as a guide structure to treat the ball, it is possible to provide a synergistic effect for improving process efficiency and improving the driving performance of the AF carrier at the same time.

The following drawings attached to the present specification 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 present invention to be described later, so that the present invention is described in these drawings It should not be construed as being limited only to the matters.
1 is a view showing the configuration of an automatic focus control device according to a preferred embodiment of the present invention;
2 is a view showing a second guide 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 illustrating a state in which the driving unit assembly of the present invention shown in FIG. 4 is coupled to the housing.
6 is a view showing a detailed configuration of a support plate according to a preferred 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 conventional or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

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

1 is a diagram showing the configuration of an automatic focus adjustment device (hereinafter referred to as 'AF device') 100 according to a preferred 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).

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

It goes without saying that the AF device 100 of the present invention is applicable not only to a device in which the AF function is implemented alone, but also to a device in which the AF and OIS are integrated and implemented. 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 body for AF driving, the housing 130 corresponds to a fixed body from a relative point of view.

The housing 130 is configured to accommodate the carrier 120 to provide an inner space in which the carrier 120 moves. can be provided in

The driving unit assembly 170 is a shape memory alloy (SMA), a piezoelectric element, a micro-electro-mechanical system (Micro Electro Mechanical System, MEMS), such as a variety of applications are possible if the carrier 120 can move in the optical axis direction. However, 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 precision control.

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

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

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

The driver 177 controls so that power of an appropriate magnitude and direction is applied to the driving coil 172 using the input signal of the Hall sensor, and feedback controls the precise position of the lens based on the optical axis direction through this cyclical 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. It may be configured to sense the position of the carrier 120 by sensing the magnetic force of the sensing magnet 127 provided separately.

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

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

The carrier 120 has a carrier ( A driving magnet 122 provided in 120 and a yoke 175 made of a metal for generating attractive force may be provided.

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

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

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

Therefore, in the case of the conventional device, since the part that faces the ball in the carrier and the housing is made of a plastic material different from the ball 140 made of a metal material, the problems as described above occur.

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

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

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

The first guide 121 or the second guide 131 may be implemented in a bent plate shape, as illustrated in FIGS. It is preferable that one of the first guide 121 or the second guide 131 is bent to form a space inward, and the other one is bent to form a space outward.

The carrier 120 or the housing 130 is typically made of a plastic material such as liquid crystal polymer (LCP), PC, or the like, 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 such a way as to be bonded to the carrier 120 or the housing 130, but in order to improve durability and increase process efficiency, the first guide ( 121) and the second guide 131 are preferably integrally molded 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 in the carrier 120 and the housing 130 , but only one of them is installed in the carrier 120 or the housing 130 depending on the embodiment. Of course, it may be provided.

The first guide 121 and the second guide 131 may preferably be formed as a groove line by a selected combination of a V-shape or U-shape in cross section to reduce frictional force 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 corresponding to each other, such as concave or convex.

In addition, the first guide 121 and the second guide 131 are shown in the drawing in the form of facing each other and provided with two left and right (based on the Y-axis) side by side on the same plane, but this is only one embodiment, and the carrier If it is a structure or shape capable of guiding the movement in the optical axis direction of 120 , it may be provided in different planes depending on the characteristics or physical structure of the device, and may be implemented in a form that does not face each other.

FIG. 4 is a view showing the configuration of the AF device 100 according to another preferred embodiment of the present invention, and FIG. 5 is a state in which the driving unit assembly 170 of the present invention shown in FIG. 4 is coupled to the housing 130 . is a diagram showing

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

As shown in FIG. 4 , the first guide 121 has a V-shape in 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 ( The 121 may be provided on the carrier 120 by a method such as bonding, of course, may be provided integrally with the carrier 120 by insert injection or the like.

The support plate 133 is configured to form one side of the housing 130 in a direction corresponding to the optical axis direction, and may be coupled to the driving unit assembly 170 through a metal-to-metal bonding method such as welding. It is preferably made of a metal material such as the like.

As described above, the support plate 133 is also more preferably configured to be integrally molded with the housing 130 through an insert injection method so that durability and efficiency of the assembly process can be improved.

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 back side of the circuit board 173, so the driving unit assembly ( 170) may be prefabricated as a single part assembly.

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

Therefore, the process of coupling the driving unit assembly 170 to the housing 130 through the conventional adhesive application, curing, and cooling processes can be omitted as a whole, thereby further improving process efficiency.

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

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

As described above, the body 1331 is bonded to the driving unit assembly 170 to correspond to a basic frame that physically supports the driving unit assembly 170 .

The first opening 1332-1 constituting the opening 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 having the Hall sensor embedded therein in the direction of the sensing magnet 127 provided in the carrier 120.

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

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

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

At least one of the guide parts 1334 and 1335 may be bent into an acceptable shape so that guiding and support of the ball 140 may be more effectively implemented as shown in FIG. 6 .

In this way, when the support plate 133 is implemented, the driving unit assembly 170 can be joined by a method such as metal-to-metal welding, so that process efficiency can be improved, as well as the ball 140 as described above. It is possible to simultaneously perform a function for the second guide 131 that treats and treats.

In the above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto and will be described below with the technical idea of the present invention by those of ordinary skill in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims.

In the above description of the present invention, modifiers such as first and second are only instrumental terms used to relatively distinguish between components, so they are used to indicate a specific order, priority, etc. It should not be construed as a term that

The accompanying drawings for the purpose of explaining the present invention and illustrating examples thereof may be shown in a somewhat exaggerated form in order to emphasize or highlight the technical contents of the present invention, but the above-described contents and matters shown in the drawings, etc. It should be construed as apparent that various types of modification application examples may be possible at the level of those skilled in the art in consideration of this.

Claims (9)

a carrier on which the lens is mounted and linearly moved in the direction of the optical axis;
a housing accommodating the carrier;
a driving unit assembly provided in the housing and configured to move the carrier in an optical axis direction; and
It is located between the carrier and the housing and includes a ball serving the carrier and the housing,
At least one of a portion of the carrier where the ball is treated or a portion of the housing where the ball is treated is made of a metal material. According to claim 1, wherein the carrier,
It further comprises a first guide made of a metal material and having a shape extending along the optical axis direction,
The automatic focus control device, characterized in that the ball is treated with the first guide. According to claim 2, wherein the carrier,
Automatic focus adjustment device, characterized in that the first guide is inserted and molded integrally. According to claim 1, wherein the housing,
It further comprises a second guide made of a metal material and having a shape extending along the optical axis direction,
The automatic focus control device, characterized in that the ball is treated with the second guide. 5. The method of claim 4, wherein the housing,
Automatic focus adjustment device, characterized in that the second guide is inserted and molded integrally. The method of claim 1,
The automatic focus adjustment device, characterized in that it further comprises a metal support plate coupled to the driving unit assembly and coupled to the housing. According to claim 6, wherein the support plate,
a body part to which the driving part assembly is coupled and an opening part for exposing the driving part assembly in the direction of the carrier is formed; and
and a guide portion extending in the lateral direction from the body portion,
The automatic focus control device, characterized in that the ball is treated to the guide part. The method of claim 7, wherein the guide part,
An automatic focus adjustment device, characterized in that a portion of the ball has a bent shape to accommodate it. The method of claim 6, wherein the housing comprises:
Automatic focus adjustment device, characterized in that the support plate is inserted and molded integrally.

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