KR101609351B1 - Actuator for ois - Google Patents

Abstract

According to the present invention, an OIS actuator comprises: a housing having an internal space formed therein; a carrier coupled to a lens assembly; magnets installed in the carrier in first and second directions which are orthogonal to each other; coils installed in a direction facing the magnets respectively to generate electromagnetic forces to the magnets respectively; first and second hall sensors configured to sense a location of the carrier based on the first and second directions; and a ball interposed between a lower portion of the carrier and a lower portion of the housing. Therefore, the OIS actuator can rapidly optimize a space utilization rate in a device and can increase efficiency of a hand trembling correction function.

Description

[0001] ACTUATOR FOR OIS [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for a camera module mounted on a portable terminal, and more particularly, to an optical actuator for correcting image distortion due to camera shake by moving a lens in a horizontal direction perpendicular to an optical axis direction.

As hardware technology for image processing has developed and user needs for image shooting have increased, autofocus (AF) has been applied to camera modules mounted on mobile terminals such as mobile phones, smart phones, PDAs, tablets, , Auto Focus), and stabilization.

In an environment where the subject and the surroundings are not sufficiently bright, such as a dark space or a night time, a relatively long exposure is necessary in order to transmit a sufficient amount of light to the image sensor.

When such a long time exposure is performed, the time during which the shaking of the lens is reflected on the image is increased, which affects the sharpness of the image, thereby causing the image to be disturbed or blurred.

In addition, in the case of a camera module mounted on a mobile terminal such as a smart phone, the fluidity of the terminal itself is high, and the hand and arm tremors generated in the human body can be easily transmitted to the camera module. In recent years, there have been more and more cases in which a user uses a self-stick when photographing an image of himself / herself as a subject. However, since a user who physically supports a mobile terminal The length of the elongated rod is extended to the arm length of the elongated body, so that the phenomenon of image blurring due to vibration or vibration becomes larger.

The stabilization technique is a technique to overcome this phenomenon. Typically, the image stabilization (DIS) (Electronic Image Stabilization (EIS)) technique, which is improved by processing through a software or the like, And an optical image stabilization (OIS) technique that physically corrects a position of a lens or an image element generated by camera shake or the like to prevent a disturbance in an image of a subject generated in the image sensor.

A device employing an optical correction method is more often used in the case of delaying an image generation time and efficiency of afterimage removal. Such an optical image stabilization technique may be equipped with a driving unit for moving the position of an optical element such as a lens (DSLR, etc.) in which a sufficient space can be secured. However, since a small-sized mobile terminal such as a smart phone is not a device for capturing images only, there is a certain limit in its application, and further, It is necessary to optimize the optical image stabilization technology for a mobile terminal having such characteristics because the characteristics such as miniaturization and lightening of the mobile terminal are required more and more.

Korean Patent Registration No. 10-1421223 discloses a technique for correcting an unintentional hand movement by using a magnet and an OIS coil member to drive a carrier equipped with a lens to an XY plane that is a plane perpendicular to the optical axis (Z axis) In this prior art, since the four elastic members in the form of a wire and the carrier on which the lens is mounted are physically supported through the spring member, it is necessary to secure a space therefor, so that the space utilization is low.

In addition, since the elasticity member of the wire is used in the structure physically supporting the carrier, if the vibration occurs due to the shaking or vibration, the excitation is sustained for a predetermined time by the physical characteristics of the elastic member itself. The energy use efficiency is low in view of the mobile terminal using the rechargeable battery.

Further, since the physical elastic means must be additionally provided, the manufacturing process of the device becomes complicated and the efficiency of the device itself is low even in terms of the life span or the service life of the device because the elastic means of the wire- .

Disclosure of Invention Technical Problem [8] The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to effectively arrange the electronic space and the physical structure for correcting the position of the lens, It is, of course, an object of the present invention to provide an OIS actuator capable of further enhancing the efficiency of a correction function due to camera shake or the like.

Other objects and advantages of the present invention will become apparent from the following description, and it will be apparent from the description of the embodiments of the present invention. Further, the objects and advantages of the present invention can be realized by a combination of the constitution shown in the claims and the constitution thereof.

According to an aspect of the present invention, there is provided an OIS actuator including: a housing having an inner space; A carrier to which the lens assembly is coupled; A magnet disposed on the carrier in mutually orthogonal first and second directions; A coil provided in a direction opposite to each of the magnets to generate an electromagnetic force in each of the magnets; First and second Hall sensors for sensing a position of the carrier on the basis of the first and second directions, respectively; And a ball interposed between a lower portion of the carrier and a lower portion of the housing.

In this case, the magnets of the present invention are formed of four, two of which are mutually symmetric with respect to the first direction and two of which are mutually symmetrical with respect to the second direction, and the balls are provided between the magnets . ≪ / RTI >

The OIS actuator of the present invention may further include four yokes provided at a lower portion of the housing and corresponding to the four magnets to generate attraction force in each of the four magnets.

In order to realize a more preferable embodiment of the present invention, a corner portion of the carrier of the present invention is provided with a support plate in which a lower bottom surface is in contact with the ball, and a portion of the ball is accommodated in a lower portion of the housing, As shown in Fig.

Further, at least one coil of the coils of the present invention is formed in a coiled form so that a space is formed at the center portion. In this case, at least one Hall sensor of the first and second Hall sensors may be provided in the middle space portion of the coil .

In addition, at least one coil of the coils of the present invention may be divided into first and second coils, wherein at least one of the first and second Hall sensors is disposed between the first and second coils .

Preferably, the yoke of the present invention may be divided into a first yoke and a second yoke. In this case, the magnet of the present invention may comprise first and second magnets corresponding to the first and second yokes, And at least one Hall sensor of the first and second Hall sensors of the present invention may be configured such that the first and second yokes are formed such that the respective parts corresponding to the first and second yokes protrude downward, As shown in FIG.

The OIS actuator according to the present invention can organically arrange the electronic and physical structures for the correction of the shaking motion to further improve the space utilization of the apparatus and further optimize the weight and miniaturization of the apparatus.

According to another embodiment of the present invention, the carrier on which the lens is mounted can be point-contacted by ball means, and the point contact can be maintained through attraction between the magnet and the yoke, Phase shift and position control can be realized more accurately and effectively.

According to another embodiment of the present invention, by arranging the magnet and the yoke to be exactly symmetrical, it is possible to more effectively guide the carrier on which the lens is mounted to return to the original position, So that even if the carrier moves in the combined direction including the rotation, it is possible to more effectively guide the carrier returning to the center center precisely.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate preferred embodiments of the invention and, together with the detailed description of the invention given below, serve to better understand the technical idea of the invention, And shall not be construed as limited to such matters.
FIG. 1 illustrates an external view of an OIS actuator according to a preferred embodiment of the present invention.
Fig. 2 is an exploded view showing a detailed configuration and coupling relationship of the OIS actuator shown in Fig. 1,
Fig. 3 is a sectional view of the center portion in the height direction and the center portion in the X-axis direction (first direction) of the OIS actuator shown in Fig. 1,
FIG. 4 is a cross-sectional view of a portion of the OIS actuator according to another preferred embodiment of the present invention in the center of the X axis direction (first direction)
Figure 5 illustrates another preferred embodiment of the coil and Hall sensor configuration of the present invention,
FIG. 6 is a cross-sectional perspective view of the OIS actuator shown in FIG. 1,
7 is a bottom view of a housing of an OIS actuator having a yoke according to another preferred embodiment of the present invention,
8 is a view showing an embodiment of a magnet corresponding to the yoke of the present invention shown in FIG.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms, and the inventor should appropriately interpret the concepts of the terms appropriately It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention based on the principle that it can be defined.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention. Therefore, various equivalents It should be understood that water and variations may be present.

The OIS actuator 100 of the present invention is an optical actuator for correcting the shaking motion. The OIS actuator 100 includes a housing 110, a carrier 120, a magnet 130, a coil 130, 140, a Hall sensor 150, a ball 160, and a yoke 170.

1, the actuator 100 of the present invention includes a housing 110 having an inner space formed therein to accommodate the structure of the present invention described later, And a shield can 115 that functions as an insulation between the upper case and the outside in combination.

As will be described later, the actuator 100 of the present invention is applied to the Hall sensor 150 in a different configuration of an apparatus (smart phone or the like) to which the actuator 100 of the present invention is mounted, The terminals 181 of the (flexible) circuit board 180 are exposed to the outside of the housing 110 for effective interfacing of power, signals, data, etc., since signals and data input / It is preferable to implement it in the form of

As shown in the drawing, the Z axis is an axial direction indicating an optical axis, and a direction in which a lens moves linearly for focus adjustment or the like, and the X axis and Y axis mean both axial directions of a plane perpendicular to the optical axis. In the following description, the first direction and the second direction are directions orthogonal to each other as the directions of both axes on the X-Y plane perpendicular to the optical axis.

As shown in FIG. 2, the carrier 120 of the present invention has a coupling space 121 at the center thereof, and a lens assembly (not shown) is coupled through the coupling space 121. By such a coupling, the carrier 120 of the present invention coincides with the physical movement of the lens assembly.

The carrier 120 according to the present invention may have various shapes as a whole, but the positional shift due to the camera-shake and the positional correction thereof are made in both directions orthogonal to each other with reference to the XY plane, so that the carrier 120 has a rectangular shape as a whole desirable.

The magnet 130 of the present invention is provided in the carrier 120 as shown in FIG. 2 and the like. When a power of a proper magnitude is applied to the coil 140 by feedback control corresponding to positional correction as described later, An electromagnetic force is generated in the magnet 140 and the carrier is moved by the electromagnetic force transmitted to the magnet. As described above, the movement of the carrier 120 may be defined as a combination of the first direction and the second direction. Accordingly, the magnet 130 of the present invention may also correspond to the carrier 120 .

The magnets 130 may be provided in the first direction and the second direction so that the magnets 130 can be balanced with each other so that the load and the volume of the actuator 100 can be balanced. In order to improve the precision of the position control and realize the feedback control more precisely in relation to the coil 140, the magnet 130 is moved in the first direction and the second direction Are symmetrically symmetrical with respect to each other.

The magnet 130 of the present invention may be provided on four sides of the carrier 120 as shown in FIGS. 2 and 3 and may be provided on the outer periphery of the bottom of the carrier 120 as shown in FIG. Meanwhile, a back yoke 131 may be further provided on the back surface of the magnet 130, that is, in a direction opposite to the coil, in order to prevent external leakage of magnetic force and to concentrate the magnetic leakage.

The coil 140 of the present invention corresponds to a driving unit that transmits a force to the magnet 130 described above, and thus is provided in a direction opposite to each of the magnets 130. Therefore, in the embodiment shown in FIG. 2, it is provided on the side of the housing 110, and in the embodiment shown in FIG. 4, it is provided below the housing 110.

As shown in FIG. 2, the coil 140 may be formed as a coiled coil so that a space is formed at the center of the coil 140, and the first coil 140-1 and / And the second coil 140-2.

When the coil 140 is divided into the first and second coils 140-1 and 140-2 in consideration of the force and direction of the magnetic force generated in the coil 140 to which the power is applied, The magnet 130 can be moved more accurately in the parallel direction and the position of the carrier 120 provided with the magnet 130 can be controlled more precisely.

The first hall sensor 150-1 and the second hall sensor 150-3 of the present invention can detect the position of each of the carriers 120 on the basis of the first and second directions, And the sensing value of the magnet in the first direction and the second direction in the second direction).

The drive modules or chips (not shown), which may be provided externally, are connected to the respective coils 140 provided in the first and second directions according to the sensed values of the Hall sensors 150-1 and 150-3 And controls the size or direction of the applied power.

In order to further maximize the space utilization, the Hall sensors 151 and 153 are arranged such that the coil 140 of the present invention is divided into the first coil 140-1 and the second coil 140-3 as shown in FIG. 5 The coil 140 may be provided between the first coil 140-1 and the second coil 140-3 and the coil 140 may be wound in a manner such that a space is formed in the middle portion as shown in FIGS. And may be provided in the center space of the coil 140 when the coil 140 is implemented as a single coil.

Since the magnitude and direction of the power applied to the coils provided in the respective directions are determined by the values output from the Hall sensors 150-1 and 150-3 and the corresponding electromagnetic force is generated, The carrier 120 moves in the first direction and the second direction, or in the combined direction. Since the Hall sensors 150-1 and 150-3 detect the position of the Hall sensors 150-1 and 150-3, and the applied power control and the generation of the electromagnetic force according to the sensed result and the movement of the carrier 120 are performed through cyclic processing, The position of the carrier 120 is precisely feedback controlled.

An actuator of this type may also be referred to as an encoding type actuator. Such an encoding type actuator can have higher control precision because it confirms the current position of the carrier (lens assembly) 120 and employs a mechanism in which the magnitude and direction of the current applied to the coil is controlled based on the identified position .

The actuator 100 according to the present invention includes a ball 160 as shown in the drawings and the like and the ball 160 is interposed between the lower portion of the carrier 120 and the lower portion of the housing 110.

That is, the carrier 120 of the present invention is placed on the ball 160 while being in point contact at the uppermost point of the ball 160, and is moved in the XY plane direction on the ball 160. Since the carrier 120 is in point contact with the ball 160 as described above, it is possible to move the carrier 120 with the frictional force minimized.

As described above, when four magnets 130 are formed, it is preferable that the balls 160 are positioned between each of the four magnets so that space utilization and physical disturbance of the magnetic force can be minimized.

In order to more precisely control the position of the carrier 120, it is further preferable that the carrier 120 keeps the point contact with the ball 160 and does not separate from the ball 160.

The yoke 170 of the present invention is provided at a lower portion of the housing 110 as shown in the figure and is provided at a position corresponding to the position where the magnet 130 is provided. The yoke 170 generates magnetic force and attracting force of the magnet 130 provided on the carrier 120 separated by the ball 160 as a magnetic body such as a metal so that the carrier 120 is not separated from the ball 160 And is continuously brought into point contact with the ball 160.

In order to balance the load and improve the accuracy of position control, when the magnet 130 is composed of four magnets as described above, the yoke 170 is also provided with four yokes .

When four yokes 170 are formed to correspond to the magnet 130, the force to pull the carrier 120 downward is uniformly generated, so that the carrier 120 tilts or tilts Can be effectively prevented.

For the implementation of the more preferred embodiment, a support plate 123 may be provided at a corner of the carrier 120, as shown in the right side of FIG. 2 and in FIG. 6, in which the lower bottom surface is in contact with the ball. The support plate 123 may be fixed to the carrier 120 on the basis of the vertical height in consideration of the separation distance between the carrier 120 and the bottom surface of the housing 110 and the attractive force between the magnet 130 and the yoke 170, It is preferable to provide a position higher than the lowermost end.

It is preferable that a receiving groove 111 is formed at a lower portion of the housing 110 so as to receive a part of the ball 160 at a position corresponding to the supporting plate 123, Do.

Hereinafter, another preferred embodiment of the present invention will be described with reference to FIGS. 7 to 8. FIG.

The embodiments of the present invention described with reference to FIGS. 7 and 8 can be applied to the configurations of the present invention described above, so that description thereof will be replaced with the foregoing description, and the main characteristic configuration of this embodiment will be mainly described .

The yoke 170 generates attraction force with the magnet 130 so that the carrier 120 is not separated from the ball 160 and the yoke 170 is located at a position corresponding to the magnet 130 And the carrier 120 is symmetrically symmetrical in four directions. Therefore, even if the carrier 120 is displaced from the top of the ball 160 due to vibration, camera shake, or the like, As shown in FIG.

In this regard, the yoke 170 of the present invention can be divided into a first yoke 170-1 and a second yoke 170-2 as shown in FIG. 7, In the case of dualization, a larger attraction force can be concentrated on the magnet 130 at the position corresponding to each yoke portion, and the attraction force to the other portion can be relatively reduced.

Therefore, when the carrier 120 moves in a combined direction, such as rotation, it is possible to concentrate the force on both ends of the magnet 130 provided on the carrier, respectively, and this attraction concentration is generated by the four magnets 130 and the corresponding four Each of the yokes 170 is simultaneously generated, so that the carrier can be more accurately guided to the original position.

In this case, as shown in FIG. 8, in order to further increase attraction concentration in each of the two yokes 170-1 and 170-3, the magnet 130 is also biased so that the first magnet 130-1 and the second magnet 130-3. Further, a portion corresponding to the first yoke 170-1 and the second yoke 170-3 may protrude downward to improve workforce concentration .

7, when the yoke 170 is separated into the first yoke 170-1 and the second yoke 170-3, the first Hall sensor 151 and the second Hall sensor 153, One or more Hall sensors 151 and 153 may be provided between the first yoke 170-1 and the second yoke 170-3 to further improve space utilization.

Although not shown in the drawing, under the actuator 100 of the present invention, there is provided an image sensor and an image processor such as a CMOS or a CCD for converting a light signal input through a lens into an electrical signal And a filter 185 for filtering the light signal may further be provided between the lens and the image sensor (processor).

In the above description of the present invention, the first and second modifiers are merely terms of a tool concept used for relatively separating the components of each other, so that they are used to indicate a specific order, priority, etc. It should be interpreted that it is not a terminology.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof and that various changes and modifications will be apparent to those skilled in the art. And various modifications and variations are possible within the scope of the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed. It should be understood that various modifications may be made in the ordinary skill in the art.

100: OIS actuator
110: housing 115: shield can
120: carrier 123: support plate
125: Magnet coupling portion
130: Magnet 131: Back yoke
140: Coils 150-1 and 150-3: Hall sensors
160: Ball 170: York
180: Flexible circuit board

Claims (10)

A housing having an inner space formed therein;
A carrier to which the lens assembly is coupled;
Two magnets provided on the carrier and symmetrical with respect to each other with respect to a first direction and a second direction orthogonal to the first direction;
A coil provided in a direction opposite to each of the magnets to generate an electromagnetic force in each of the magnets;
First and second Hall sensors for sensing a position of the carrier on the basis of the first and second directions, respectively;
A ball interposed between a lower portion of the carrier and a lower portion of the housing and positioned between the magnets; And
And four yokes provided at a lower portion of the housing and corresponding to the four magnets to generate attraction force in each of the four magnets and divided into first and second yokes, OIS actuator. delete delete The carrier according to claim 1, wherein, in a corner portion of the carrier,
And a support plate on which the lower bottom surface is in contact with the ball,
In the lower portion of the housing,
And an accommodating groove for accommodating a part of the ball is provided at a position corresponding to the support plate. 2. The apparatus of claim 1, wherein at least one of the coils comprises:
And is wound in such a manner that a space is formed in the middle portion thereof,
Wherein at least one of the first and second Hall sensors comprises:
Wherein the OIS actuator is provided in a middle space portion of the coil. 2. The apparatus of claim 1, wherein at least one of the coils comprises:
And the second coil is divided into first and second coils. 7. The apparatus of claim 6, wherein at least one of the first and second Hall sensors comprises:
Wherein the OIS actuator is provided between the first and second coils. delete The magnetron according to claim 1,
Wherein the first and second yokes are formed of first and second magnets so as to correspond to the first and second yokes, or the respective portions corresponding to the first and second yokes protrude downward. The apparatus of claim 1, wherein at least one of the first and second Hall sensors comprises:
And the second yoke is provided between the first yoke and the second yoke.

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