KR20180112689A - Camera module and actuator thereof - Google Patents

Abstract

According to an embodiment of the present invention, an actuator of a camera module includes a part to be detected and a position detecting part arranged to face the part to be detected and including at least two sensing coils forming at least two oscillation circuits, respectively. The position detecting part can detect the position of the part to be detected according to the at least two oscillation signals with different frequency ranges generated in the at least two oscillation circuits. Accordingly, the present invention can precisely detect a magnet without adopting a hall sensor.

Description

[0001] CAMERA MODULE AND ACTUATOR THEREOF [0002]

The present invention relates to a camera module of a camera module and an actuator therefor.

2. Description of the Related Art Generally, portable communication terminals such as mobile phones, PDAs, portable PCs, and the like have recently become popular not only to transmit character or voice data but also to transmit image data. In order to respond to such trend, image data transmission, video chatting, and the like can be performed, a camera module is basically installed in a portable communication terminal.

Generally, the camera module includes a lens barrel having a lens therein and a housing for accommodating the lens barrel therein, and includes an image sensor for converting an image of the subject into an electric signal. The camera module can employ a short-focus camera module that shoots objects with a fixed focus. Recently, a camera module including an actuator capable of autofocus (AF) adjustment has been adopted according to technology development. In addition, the camera module employs an actuator for optical image stabilization (OIS) in order to reduce the resolution degradation due to hand movement.

Korean Patent Laid-Open Publication No. 2013-0077216

SUMMARY OF THE INVENTION The present invention provides a camera module and its actuator capable of precisely detecting the position of a magnet without employing a Hall sensor.

The actuator of the camera module according to an embodiment of the present invention includes a position detection portion including a detected portion and at least two sensing coils disposed opposite to the detected portion and each forming at least two oscillation circuits, The detection unit may detect the position of the to-be-detected portion according to at least two oscillation signals having different frequency ranges generated by the at least two oscillation circuits.

The camera module and the actuator thereof according to the embodiment of the present invention can precisely detect the position of the lens barrel from the change of the inductance of the sensing coil. Furthermore, since no separate Hall sensor is employed, the manufacturing cost of the camera module and its actuator can be reduced, and space efficiency can be improved.

1 is a perspective view of a camera module according to an embodiment of the present invention.
2A is a schematic exploded perspective view of a camera module according to an embodiment of the present invention.
2B is a developed view of a sensing coil and a driving coil disposed on a substrate according to an embodiment of the present invention.
3 is a block diagram of a main part of an actuator employed in a camera module according to an embodiment of the present invention.
4 is a block diagram illustrating a position detector according to an embodiment of the present invention.
5 shows frequencies of a plurality of oscillation signals in accordance with movement of the detected part in the Z-axis direction according to an embodiment of the present invention.
6 shows frequencies of a plurality of oscillation signals in accordance with movement of the detected part in the X-axis direction according to an embodiment of the present invention.
7 shows frequencies of a plurality of oscillation signals in accordance with movement of the detected part in the Y-axis direction according to an embodiment of the present invention.

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

However, the embodiments of the present invention can be modified into various other forms, and the scope of the present invention is not limited to the embodiments described below. Further, the embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, the particular shapes, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with one embodiment.

Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

FIG. 1 is a perspective view of a camera module according to an embodiment of the present invention. FIG. 2 is a schematic exploded perspective view of a camera module according to an embodiment of the present invention. FIG. 2 is a developed view of a sensing coil and a driving coil. FIG.

1, 2A and 2B, a camera module 100 according to an exemplary embodiment of the present invention includes a lens barrel 210, an actuator for moving the lens barrel 210, and a lens barrel 210, And an image sensor module 700 that includes a housing 110 and a housing 120 for accommodating the actuator and further converts light incident through the lens barrel 210 into an electric signal.

The lens barrel 210 may have a hollow cylindrical shape so that a plurality of lenses for capturing an object can be accommodated therein, and a plurality of lenses are mounted on the lens barrel 210 along the optical axis. The plurality of lenses are arranged as many as necessary according to the design of the lens barrel 210, and each lens has the same or different optical characteristics such as a refractive index.

The actuator can move the lens barrel 210. For example, the actuator can adjust the focus by moving the lens barrel 210 in the optical axis (Z-axis) direction and move the lens barrel 210 in the direction perpendicular to the optical axis (Z-axis) can do. The actuator includes a focus adjustment unit 400 for adjusting the focus and a shake correction unit 500 for correcting the shake.

The image sensor module 700 can convert light incident through the lens barrel 210 into an electric signal. As an example, the image sensor module 700 may include a printed circuit board 720 connected to the image sensor 710 and the image sensor 710, and may further include an infrared filter. The infrared filter blocks light in the infrared region of light incident through the lens barrel 210. The image sensor 710 converts the light incident through the lens barrel 210 into an electric signal. For example, the image sensor 710 may include a Charge Coupled Device (CCD) or a Complementary Metal-Oxide Semiconductor (CMOS). The electric signal converted by the image sensor 710 is outputted as an image through a display unit of a portable electronic device. The image sensor 710 is fixed to the printed circuit board 720 and is electrically connected to the printed circuit board 720 by wire bonding.

The lens barrel 210 and the actuator are housed in the housing 120. For example, the housing 120 has an open top and a bottom, and the lens barrel 210 and the actuator are accommodated in the inner space of the housing 120. The image sensor module 700 is disposed below the housing 120.

The case 110 is coupled to the housing 120 so as to enclose the outer surface of the housing 120 and can protect internal components of the camera module 100. Further, the case 110 can shield electromagnetic waves. For example, the case 110 may shield the electromagnetic wave so that the electromagnetic wave generated in the camera module does not affect other electronic components in the portable electronic device. In addition, portable electronic devices are equipped with various electronic components in addition to the camera module, so that the case 110 can shield electromagnetic waves so that electromagnetic waves generated from such electronic components do not affect the camera module. The case 110 may be made of a metal material and may be grounded to a ground pad provided on the printed circuit board 720, thereby shielding electromagnetic waves.

The actuator according to an embodiment of the present invention moves the lens barrel 210 to focus on the subject. For example, the actuator includes a focus adjustment unit 400 that moves the lens barrel 210 in the optical axis (Z-axis) direction.

The focus adjusting unit 400 includes a magnet 410 and a driving coil 430 for generating a driving force to move the carrier 300 accommodating the lens barrel 210 and the lens barrel 210 in the optical axis direction .

The magnet 410 is mounted on the carrier 300. In one example, the magnet 410 may be mounted on one side of the carrier 300. The driving coil 430 may be mounted on the housing 120 and disposed opposite to the magnet 410. For example, the driving coil 430 may be disposed on one side of the substrate 600, and the substrate 600 may be mounted on the housing 120.

The magnet 410 may be mounted on the carrier 300 and move along with the carrier 300 in the direction of the optical axis (Z-axis), and the driving coil 430 may be fixed to the housing 120. However, according to the embodiment, the positions of the magnet 410 and the driving coil 430 may be changed from each other.

When the driving signal is applied to the driving coil 430, the carrier 300 can move in the direction of the optical axis (Z axis) by the electromagnetic interaction between the magnet 410 and the driving coil 430.

The lens barrel 210 is accommodated in the carrier 300 and the lens barrel 210 is also moved in the optical axis direction (Z-axis direction) by the movement of the carrier 300. [ The frame 310 and the lens holder 320 are also received in the carrier 300 so that the frame 310, the lens holder 320 and the lens barrel 210 are also moved along the optical axis Z axis) direction.

A rolling member B1 is disposed between the carrier 300 and the housing 120 to reduce friction between the carrier 300 and the housing 120 when the carrier 300 is moved. The rolling member B1 may be in the form of a ball. The rolling member B1 is disposed on both sides of the magnet 410. [

A yoke 450 is disposed in the housing 120. In one example, the yoke 450 is mounted to the substrate 600 and disposed in the housing 120. The yoke 450 is provided on the other surface of the substrate 600. Accordingly, the yoke 450 is disposed to face the magnet 410 with the drive coil 430 interposed therebetween. A attraction force acts between the yoke 450 and the magnet 410 in a direction perpendicular to the optical axis (Z-axis). The rolling member B1 can maintain contact with the carrier 300 and the housing 120 by the attraction between the yoke 450 and the magnet 410. [ In addition, the yoke 450 can collect the magnetic force of the magnet 410 and prevent leakage magnetic flux from being generated. For example, the yoke 450 and the magnet 410 form a magnetic circuit.

The present invention uses a closed-loop control method in which the position of the lens barrel 210 is sensed and fed back in the focus adjustment process. Accordingly, the focus adjustment unit 400 may include a position detection unit for closed loop control. The position detection unit may include AF sensing coils 470a and 470b, and the AF sensing coils 470a and 470b may be disposed along an optical axis (Z axis). The inductance of the AF sensing coils 470a and 470b changes in accordance with the movement of the magnet 410 facing the AF sensing coils 470a and 470b. The position detection unit can detect the position of the lens barrel 210 from the change in inductance of the AF sensing coils 470a and 470b according to the movement of the magnet 410 in the optical axis (Z-axis) direction. According to the embodiment, the focus adjustment unit 400 may further include a first sensing yoke 460 disposed on one side of the magnet 410 so as to face the AF sensing coils 470a and 470b. The first sensing yoke 460 may be mounted on the carrier 300 and move along the optical axis (Z-axis) together with the carrier 300. The first sensing yoke 460 may be formed of at least one of a conductor and a magnetic body. When the first sensing yoke 460 is provided, the position detecting unit detects a change in the inductance of the AF sensing coils 470a and 470b due to the movement of the first sensing yoke 460 in the direction of the optical axis (Z-axis) Can be detected. That is, the inductance of the AF sensing coils 470a and 470b may be changed according to the displacement of the magnet 410 or the first sensing yoke 460. When the magnet 410 or the first sensing yoke moves in the direction of the optical axis (Z-axis), the areas of the magnet 410 or the first sensing yoke overlap with the AF sensing coils 470a and 470b, The inductance of the sensing coils 470a and 470b can be changed.

The position detecting unit of the focus adjusting unit 400 may further include at least one capacitor to determine the displacement of the lens barrel 210 from the change of the inductance of the at least one AF sensing coil 470a and 470b. At least one of the capacitors and the AF sensing coils 470a and 470b may form a predetermined oscillation circuit. For example, at least one capacitor may be provided corresponding to the number of the AF sensing coils 470a and 470b so that one capacitor and one sensing coil may be configured in the same manner as a predetermined LC oscillator, It can be configured in the form of an oscillator.

The position detection unit of the focus adjustment unit 400 can determine the displacement of the lens barrel 210 from the frequency change of the oscillation signal generated in the oscillation circuit. Specifically, when the inductance of the AF sensing coils 470a and 470b forming the oscillation circuit is changed, the frequency of the oscillation signal generated in the oscillation circuit is changed, It is possible to detect the displacement of the object.

The shake correction unit 500 is used for correcting an image blurring or a motion blur due to factors such as a user's hand motion during image shooting or motion picture shooting. For example, the shake correction unit 500 compensates for the shake when a shake occurs during image shooting due to user's hand shake or the like, by giving a relative displacement corresponding to the shake to the lens barrel 210. For example, the shake correction unit 500 moves the lens barrel 210 in a direction perpendicular to the optical axis (Z-axis) to correct the shake.

The shake correction unit 500 includes a plurality of magnets 510a and 520a and a plurality of driving coils 510b and 520b that generate a driving force to move the guide member in a direction perpendicular to the optical axis (Z axis). The frame 310 and the lens holder 320 are inserted into the carrier 300 and arranged in the direction of the optical axis (Z-axis) to guide the movement of the lens barrel 210. The frame 310 and the lens holder 320 have a space into which the lens barrel 210 can be inserted. The lens barrel 210 is inserted and fixed in the lens holder 320.

The frame 310 and the lens holder 320 are fixed to the carrier 300 by the driving force generated by the electromagnetic interaction between the plurality of magnets 510a and 520a and the plurality of driving coils 510b and 520b, Z-axis). Among the plurality of magnets 510a and 520a and the plurality of drive coils 510b and 520b, the first magnet 510a and the first drive coil 510b have a first axis (Y axis) perpendicular to the optical axis (Z axis) And the second magnet 520a and the second drive coil 520b generate a driving force in a second axis (X axis) direction perpendicular to the first axis (Y axis). Here, the second axis (X axis) means an axis perpendicular to both the optical axis (Z axis) and the first axis (Y axis). The plurality of magnets 510a and 520a are arranged to be perpendicular to each other in a plane perpendicular to the optical axis (Z axis).

The plurality of magnets 510a and 520a are mounted on the lens holder 320 and the plurality of driving coils 510b and 520b facing the plurality of magnets 510a and 520a are disposed on the substrate 600, .

The plurality of magnets 510a and 520a can move in a direction perpendicular to the optical axis (Z-axis) together with the lens holder 320 and the plurality of driving coils 510b and 520b can be fixed to the housing 120. However, according to the embodiment, the positions of the plurality of magnets 510a and 520a and the plurality of driving coils 510b and 520b may be mutually changed.

The present invention uses a closed-loop control method in which the position of the lens barrel 210 is sensed and fed back in the shake correction process. Therefore, the shake correction unit 500 may include a position detection unit for controlling the closed loop, and may include a second sensing yoke 530a to be detected by the shake correction unit 500. [ The position detection unit may include OIS sensing coils 530b and 530c disposed along the X axis. The second sensing yoke 530a is attached to the lens holder 320 and the OIS sensing coils 530b and 530c are disposed on the substrate 600 and mounted on the housing 120. The second sensing yoke 530a and the OIS sensing coils 530b and 530c may face each other in a direction perpendicular to the optical axis (Z-axis).

The inductance of the OIS sensing coils 530b and 530c changes in accordance with the movement of the second sensing yoke 530a facing the OIS sensing coils 530b and 530c. The position detection unit detects the position of the lens barrel 210 from the inductance changes of the OIS sensing coils 530b and 530c according to the movement in two directions (X axis direction, Y axis direction) perpendicular to the optical axis of the second sensing yoke can do.

When the second sensing yoke 530a moves in the X axis direction, the area of the second sensing yoke 530a which overlaps with the OIS sensing coils 530b and 530c changes and the inductance of the OIS sensing coils 530b and 530c Can be changed. When the second sensing yoke 530a moves in the Y axis direction, the distance between the OIS sensing coils 530b and 530c and the second sensing yoke 530a changes and the inductance of the OIS sensing coils 530b and 530c changes .

The position detection unit of the shake correction unit 500 may additionally include at least one capacitor to determine the displacement of the lens barrel 210 from the change in inductance of the OIS sensing coils 530b and 530c. At least one of the capacitors and the OIS sensing coils 530b and 530c may form a predetermined oscillation circuit. For example, the at least one capacitor may be provided corresponding to the number of the OIS sensing coils 530b and 530c so that one capacitor and one sensing coil may be formed in the form of a predetermined LC oscillator, And may be configured in the form of a colpitts oscillator.

The position detection unit of the shake correction unit 500 can determine the displacement of the lens barrel 210 from the frequency change of the oscillation signal generated in the oscillation circuit. Specifically, when the inductance of the OIS sensing coils 530b and 530c forming the oscillation circuit is changed, since the frequency of the oscillation signal generated in the oscillation circuit is changed, the displacement detection of the lens barrel 210 is performed based on the change in frequency It can be possible.

The position detection unit of the shake correction unit 500 may further include a reference coil 530d provided on one side of the OIS sensing coils 530b and 530c. The position detection unit of the shake correction unit 500 can generate an oscillation signal corresponding to the inductance of the reference coil 530d and calculate a common noise component flowing into the camera module from the frequency of the generated oscillation signal. The position detection section of the shake correction section 500 can remove the common noise component at the frequency of the oscillation signal calculated from the OIS sensing coils 530b and 530c and improve the reliability of the displacement detection of the lens barrel 210. [

Meanwhile, the camera module 100 includes a plurality of ball members that support the shake correction unit 500. The plurality of ball members serve to guide movement of the frame 310, the lens holder 320, and the lens barrel 210 in the shake correction process. It also functions to maintain the spacing between the carrier 300, the frame 310, and the lens holder 320.

The plurality of ball members includes a first ball member B2 and a second ball member B3. The first ball member B2 guides movement of the frame 310, the lens holder 320 and the lens barrel 210 in the direction of the first axis (Y axis), and the second ball member B3 guides the movement of the frame 310, (X-axis) direction of the lens barrel 320 and the lens barrel 210 as shown in FIG.

For example, when the driving force is generated in the first axis (Y axis) direction, the first ball member B2 rolls in the first axis (Y axis) direction. Accordingly, the first ball member B2 guides the movement of the frame 310, the lens holder 320, and the lens barrel 210 in the direction of the first axis (Y axis). In addition, the second ball member B3 rolls in the second axis (X axis) direction when a driving force is generated in the second axis (X axis) direction. Accordingly, the second ball member B3 guides the movement of the lens holder 320 and the lens barrel 210 in the direction of the second axis (X axis).

The first ball member B2 includes a plurality of ball members disposed between the carrier 300 and the frame 310 and the second ball member B3 is disposed between the frame 310 and the lens holder 320 And a plurality of ball members.

A first guide groove portion 301 for receiving the first ball member B2 is formed on a surface of the carrier 300 and the frame 310 facing each other in the optical axis direction (Z-axis direction). The first guide groove portion 301 includes a plurality of guide grooves corresponding to the plurality of ball members of the first ball member B2. The first ball member B2 is accommodated in the first guide groove 301 and is sandwiched between the carrier 300 and the frame 310. The movement of the first ball member B2 in the direction of the optical axis (Z-axis) and the second axis (X-axis) is restricted in the state of being accommodated in the first guide groove 301, Lt; / RTI > For example, the first ball member B2 can roll only in the first axis (Y axis) direction. To this end, the planar shape of each of the plurality of guide grooves of the first guide groove portion 301 may be a rectangle having a length in the direction of the first axis (Y axis).

A second guide groove 311 for receiving the second ball member B3 is formed on the surface of the frame 310 and the lens holder 320 facing each other in the optical axis direction (Z-axis direction). The second guide groove 311 includes a plurality of guide grooves corresponding to the plurality of ball members of the second ball member B3.

The second ball member B3 is accommodated in the second guide groove 311 and is sandwiched between the frame 310 and the lens holder 320. The movement of the second ball member B3 in the direction of the optical axis (Z-axis) and the first axis (Y-axis) is restricted in the state of being accommodated in the second guide groove 311, Lt; / RTI > For example, the second ball member B3 can roll only in the second axis (X-axis) direction. To this end, the plane shape of each of the plurality of guide grooves of the second guide groove 311 may be a rectangle having a length in the direction of the second axis (X axis).

In the present invention, a third ball member B4 for supporting the movement of the lens holder 320 between the carrier 300 and the lens holder 320 is provided. The third ball member B4 guides both the movement of the lens holder 320 in the direction of the first axis (Y axis) and the movement in the direction of the second axis (X axis).

For example, the third ball member B4 rolls in the first axis (Y axis) direction when a driving force is generated in the first axis (Y axis) direction. Accordingly, the third ball member B4 guides the movement of the lens holder 320 in the direction of the first axis (Y axis).

Further, the third ball member B4 rolls in the second axis (X axis) direction when a driving force is generated in the second axis (X axis) direction. Accordingly, the third ball member B4 guides the movement of the lens holder 320 in the direction of the second axis (X axis). On the other hand, the second ball member B3 and the third ball member B4 support the lens holder 320 in contact with each other.

On the surface of the carrier 300 and the lens holder 320 facing each other in the optical axis direction (Z-axis direction), a third guide groove portion 302 for accommodating the third ball member B4 is formed. The third ball member B4 is accommodated in the third guide groove 302 and is sandwiched between the carrier 300 and the lens holder 320. [ The movement of the third ball member B4 in the direction of the optical axis (Z-axis) is restricted in the state in which the third ball member B4 is accommodated in the third guide groove 302 and the movement of the third ball member B4 in the X- You can exercise your clouds. For this, the third guide groove 302 may have a circular planar shape. Therefore, the third guide groove portion 302, the first guide groove portion 301, and the second guide groove portion 311 may have different plan shapes.

The first ball member B2 is capable of rolling in the direction of the first axis (Y axis), the second ball member B3 is capable of rolling in the direction of the second axis (X axis), and the third ball member B4 Is capable of rolling in the direction of the first axis (Y axis) and the second axis (X axis). Therefore, the plurality of ball members for supporting the shake correction unit 500 of the present invention are different in degrees of freedom. Here, the degree of freedom may mean the number of independent variables required to represent the motion state of an object in a three-dimensional coordinate system. Generally, the degree of freedom of an object in a three-dimensional coordinate system is six. The motion of an object can be expressed by three orthogonal coordinate systems and three rotational coordinate systems. For example, in a three-dimensional coordinate system, an object can translate along each axis (X axis, Y axis, Z axis) and rotate about each axis (X axis, Y axis, Z axis).

In this specification, the degree of freedom means that when the shake correction unit 500 is moved by the driving force generated in a direction perpendicular to the optical axis (Z-axis) by applying power to the shake correction unit 500, The second ball member B3, and the third ball member B4 in order to indicate the movement of the first ball member B2, the second ball member B3, and the third ball member B4. For example, the third ball member B4 is moved in a rolling motion along two axes (a first axis (Y axis) and a second axis (X axis)) by a driving force generated in a direction perpendicular to the optical axis (Z axis) And the first ball member B2 and the second ball member B3 are rollable along one axis (the first axis (Y axis) or the second axis (X axis)). Therefore, the degree of freedom of the third ball member B4 is greater than the degree of freedom of the first ball member B2 and the second ball member B3.

The frame 310, the lens holder 320, and the lens barrel 210 move together in the first axis (Y axis) direction when a driving force is generated in the first axis (Y axis) direction. Here, the first ball member B2 and the third ball member B4 roll in the first axis (Y axis). At this time, the movement of the second ball member B3 is restricted.

When the driving force is generated in the second axis (X axis) direction, the lens holder 320 and the lens barrel 210 move in the second axis (X axis) direction. Here, the second ball member B3 and the third ball member B4 roll along the second axis (X axis). At this time, the movement of the first ball member B2 is limited.

In the present invention, a plurality of yokes 510c and 520c are provided so that the shake correcting unit 500 and the first to third ball members B2, B3 and B4 are kept in contact with each other. The plurality of yokes 510c and 520c are fixed to the carrier 300 and arranged to face the plurality of magnets 510a and 520a in the optical axis direction (Z axis). Thus, attraction is generated between the plurality of yokes 510c and 520c and the plurality of magnets 510a and 520a in the direction of the optical axis (Z axis). The shake correction unit 500 is pressed in the direction toward the plurality of yokes 510c and 520c by the attraction force between the plurality of yokes 510c and 520c and the plurality of magnets 510a and 520a, The frame 310 and the lens holder 320 of the first to third ball members B2, B3, and B4 can be kept in contact with each other. The plurality of yokes 510c and 520c are materials capable of generating attractive force with the plurality of magnets 510a and 520a. In one example, the plurality of yokes 510c and 520c are provided as a magnetic body.

The present invention provides a plurality of yokes 510c and 520c to maintain the frame 310 and the lens holder 320 in contact with the first to third ball members B2 to B3 and B4, A stopper 330 is provided to prevent the first through third ball members B2, B3 and B4, the frame 310 and the lens holder 320 from being released to the outside of the carrier 300. The stopper 330 is coupled to the carrier 300 so as to cover at least a part of the upper surface of the lens holder 320.

3 is a block diagram of a main part of an actuator employed in a camera module according to an embodiment of the present invention. The actuator 1000 according to the embodiment of FIG. 3 may correspond to the focus adjustment unit 400 and the shake correction unit 500 of FIG.

When the actuator 1000 of FIG. 3 corresponds to the focus adjusting unit 400 of FIG. 2A, the lens barrel may be moved in the optical axis direction to perform an auto focus (AF) function of the camera module. Therefore, when the actuator 1000 of FIG. 3 performs the auto focus function, the driving unit 1100 may apply a driving signal to the driving coil 1200 to provide driving force in the optical axis direction to the lens barrel.

When the actuator 1000 of FIG. 3 corresponds to the shake correction unit 500 of FIG. 2A, the lens barrel is moved in a direction perpendicular to the optical axis to perform an optical image stabilization (OIS) function of the camera module . Accordingly, when the actuator 1000 of FIG. 3 performs the optical shake correction function, the driving unit 1100 applies a driving signal to the driving coil 1200 to drive the driven unit 1200 in the direction perpendicular to the optical axis .

The actuator 1000 according to an embodiment of the present invention may include a driving unit 1100, a driving coil 1200, a detected unit 1300, and a position detector 1400.

The driving unit 1100 generates the driving signal Sdr in accordance with the input signal Sin applied from the outside and the feedback signal Sf generated from the position detection unit 1400 and supplies the generated driving signal Sdr to the driving coil 1200).

When the driving signal Sdr provided from the driving unit 1100 is applied to the driving coil 1200, the lens barrel can move in a direction perpendicular to the optical axis by an electromagnetic interaction between the driving coil 1200 and the magnet.

The position detection unit 1400 detects the position of the lens barrel moving by the electromagnetic interaction between the driving coil 1200 and the magnet through the detected part 1300 to generate the feedback signal Sf and outputs the feedback signal Sf, May be provided to the driving unit 1100.

The detected portion 1300 may be provided on one side of the lens barrel so as to move in the same direction as the moving direction of the lens barrel. And the detected part 1300 provided on one side of the lens barrel can face the sensing coil of the position detecting part 1400. [ According to the embodiment, the to-be-detected portion 1300 may be provided in a plurality of frames that engage with the lens barrel in addition to the lens barrel. The detected part 1300 may be composed of either a magnetic body or a conductor. For example, the detected part 1300 may correspond to the magnet 410, the first sensing yoke 460, and the second sensing yoke 530a of FIG. 2A.

The position detection unit 1400 includes at least one sensing coil and can detect the position of the detected unit 1300 by converting the inductance of the sensing coil that varies according to the movement of the detected unit 1300 into a frequency. At this time, at least one sensing coil included in the position detection unit 1400 may correspond to at least one sensing coil included in the focus adjustment unit 400 and the shake correction unit 500 of FIG. 2A.

4 is a block diagram illustrating a position detector according to an embodiment of the present invention. Hereinafter, the position detecting operation of the detected portion 1300 by the position detecting portion 1400 will be described with reference to Figs. 2A, 2B, 3, and 4. Fig.

The position detector 1400 according to an embodiment of the present invention may include an oscillator 1410, an arithmetic unit 1430, and a determiner 1450.

The oscillation unit 1410 may include a plurality of oscillation circuits to generate a plurality of oscillation signals Sosc. The plurality of oscillation circuits may include a first oscillation circuit 1410a and a second oscillation circuit 1410b and each of the first oscillation circuit 1410a and the second oscillation circuit 1410b may include a sensing coil and a capacitor , A predetermined LC oscillator can be configured. Specifically, the first oscillation circuit 1410a may include a first sensing coil L1 and a first capacitor C1, and the second oscillation circuit 1410b may include a second sensing coil L2 and a second capacitor (C2). The first sensing coil L1 and the second sensing coil L2 provided in the first oscillation circuit 1410a and the second oscillation circuit 1410b are connected to the AF sensing coil Or may correspond to at least one of the OIS sensing coils 530b and 530c included in the shake correction unit 500 of FIG.

The first sensing coil L1 and the second sensing coil L2 can detect the displacement of the detected portion 1300 facing the first sensing coil L1 and the second sensing coil L2. The first sensing coil L1 and the second sensing coil L2 detect the displacement of the detected portion 1300 in a direction perpendicular to the plane on which the first sensing coil L1 and the second sensing coil L2 are disposed can do. Since the first sensing coil L1 and the second sensing coil L2 are disposed on the same plane, the inductances of the first sensing coil L1 and the second sensing coil L2 are the same as those of the first sensing coil L1 and the second sensing coil L2, Can be changed in the same direction according to the movement of the detected portion 1300 in the direction perpendicular to the plane on which the sensing coil L2 is disposed. 2A, the first sensing coil L1 and the second sensing coil L2 correspond to at least one OIS sensing coil 530b and 530c included in the shake correction unit 500 of FIG. 2A The OIS sensing coils 530b and 530c can detect the displacement in the Y axis direction of the sensing yoke 530a disposed opposite to the OIS sensing coils 530b and 530c.

The first sensing coil L1 and the second sensing coil L2 may detect the displacement of the detected portion 1300 in the direction in which the first sensing coil L1 and the second sensing coil L2 are arranged . The inductances of the first sensing coil L1 and the second sensing coil L2 are different from each other when the detected portion 1300 moves along the direction in which the first sensing coil L1 and the second sensing coil L2 are disposed. It can be changed in another direction. 2A, the first sensing coil L1 and the second sensing coil L2 correspond to at least one OIS sensing coil 530b and 530c included in the shake correction unit 500 of FIG. 2A The OIS sensing coils 530b and 530c can detect the displacement in the X axis direction of the second sensing yoke 530a disposed opposite to the OIS sensing coils 530b and 530c. When the first sensing coil L1 and the second sensing coil L2 correspond to the AF sensing coils 470a and 470b included in the focus adjusting unit 400 of FIG. 2A, the AF sensing coils 470a and 470b Can detect the displacement in the Z-axis direction of the first sensing yoke opposed to the AF sensing coils 470a and 470b.

The first oscillation circuit 1410a and the second oscillation circuit 1410b of FIG. 3 are schematically illustrated, and the first oscillation circuit 1410a and the second oscillation circuit 1410b are in the form of various well-known oscillators Lt; / RTI >

The frequency of the oscillation signal Sosc of the first oscillation circuit 1410a and the second oscillation circuit 1410b is determined by the inductance of the first sensing coil L1, the inductance of the second sensing coil L2, And the capacitance of the second capacitor C2. When the oscillation circuit is implemented by an LC oscillator including a sensing coil and a capacitor, the frequency f of the oscillation signal Sosc can be expressed by the following equation (1). In Equation 1, 1 represents the inductance of the first sensing coil L1 and the second sensing coil L2, and c represents the capacitance of the first capacitor C1 and the second capacitor C2.

The intensity of the magnetic field of the detected part 1300 which influences the inductances of the first sensing coil L1 and the second sensing coil L2 of the oscillating part 1410 is The inductances of the first sensing coil L1 and the second sensing coil L2 can be changed. Therefore, the frequencies of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 output from the first oscillation circuit 1410a and the second oscillation circuit 1410b can be changed according to the movement of the to-be-detected portion 1300 . According to an embodiment of the present invention, in order to increase the rate of change of the inductance of the first sensing coil L1 and the second sensing coil L2 in accordance with the movement of the detected part 1300, the detected part 1300 and the oscillating part Magnetic material having a high magnetic permeability can be disposed between the first and second magnetic layers 1410 and 1410. [

The frequency range of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 generated by the first oscillation circuit 1410a and the second oscillation circuit 1410b may be different from each other have. For example, the frequency range of the first oscillation signal Sosc1 may correspond to the low frequency range, and the frequency range of the second oscillation signal Sosc2 may be the high frequency range.

According to an embodiment of the present invention, two oscillation circuits disposed adjacent to each other generate oscillation signals in different frequency ranges, thereby eliminating interference between a plurality of oscillation signals.

The inductance of the first sensing coil L1 of the first oscillating circuit 1410a and the capacitance of the first capacitor C1 are set to the same value as that of the second sensing circuit 1410b of the second oscillating circuit 1410b in order to generate oscillation signals of different frequency ranges. The inductance of the coil L2, and the capacitance of the second capacitor C2. For example, the first oscillation circuit 1410a and the second oscillation circuit 1410b may have the same inductance, different capacitances, the same capacitance, the same inductance, or different capacitance and inductance.

On the other hand, according to the embodiment, unlike the above, the two oscillation circuits can generate oscillation signals of the same frequency domain band. To this end, the inductance and the capacitance of the first oscillation circuit 1410a and the second oscillation circuit 1410b may be the same.

The operation unit 1430 can calculate the frequencies f_Sosc1 and f_Sosc2 of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 output from the first oscillation circuit 1410a and the second oscillation circuit 1410b . For example, the operation unit 1430 can calculate the frequencies f_Sosc1 and f_Sosc2 of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 using the reference clock CLK. Specifically, the operation unit 1430 can count the first oscillation signal Sosc1 and the second oscillation signal Sosc2 using the reference clock CLK. The reference clock CLK is a clock signal having an extremely high frequency and is used for counting the first oscillation signal Sosc1 and the second oscillation signal Sosc2 of one cycle during the reference period with the reference clock CLK The count value of the reference clock CLK corresponding to the first oscillation signal Sosc1 and the second oscillation signal Sosc2 of one period can be calculated. The operation unit 1430 calculates the frequencies f_Sosc1 and f_Sosc2 of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 using the count value of the reference clock CLK and the frequency of the reference clock CLK can do.

The determination unit 1450 receives the frequencies f_Sosc1 and f_Sosc2 of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 from the operation unit 1430 and receives the first oscillation signal Sosc1 and the second oscillation signal It is possible to determine the position of the detected part 1300 in accordance with the frequencies f_Sosc1 and f_Sosc2. The determination unit 1450 may include a memory and the memory may store position information of the detected unit 1300 corresponding to the frequency f_Sosc of the oscillation signal Sosc. The memory may be implemented as a non-volatile memory including one of a flash memory, an Electrically Erasable Programmable Read-Only Memory (EEPROM), and a Ferroelectric RAM (FeRAM).

When the frequencies f_Sosc1 and f_Sosc2 of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 are transmitted from the operation unit 1430, the determination unit 1450 determines the position information of the detected unit 1300 The position of the to-be-detected portion 1300 can be determined.

5 shows frequencies of a plurality of oscillation signals in accordance with movement of the detected part in the Z-axis direction according to an embodiment of the present invention.

In this embodiment, it is assumed that the first sensing coil L1 and the second sensing coil L2 correspond to the AF sensing coils 470a and 470b included in the focus adjusting unit 400 of FIG. 2A. When the detected part 1300 moves in the Z-axis direction, the inductances of the first sensing coil L1 and the second sensing coil L2 increase or decrease in different directions. Therefore, when the detected part 1300 moves in the Z-axis direction, the first oscillation signal Sosc1 and the second oscillation signal Sosc2 generated by the first sensing coil L1 and the second sensing coil L2, May be different from each other.

Referring to FIG. 5A, the frequency ranges of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 may be different from each other. For example, the highest frequency of the second oscillation signal Sosc2 in the low frequency region may be lower than the lowest frequency of the first oscillation signal Sosc1 in the high frequency region.

According to an embodiment of the present invention, two oscillation circuits disposed adjacent to each other generate oscillation signals in different frequency ranges, thereby eliminating interference between a plurality of oscillation signals. 5 (b), the frequency ranges of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 are the same, and the first oscillation signal Sosc1, And the frequency of the second oscillation signal Sosc2 may intersect with each other at one point.

6 shows frequencies of a plurality of oscillation signals in accordance with movement of the detected part in the X-axis direction according to an embodiment of the present invention.

In this embodiment, it is assumed that the first sensing coil L1 and the second sensing coil L2 correspond to at least one OIS sensing coil 530b, 530c included in the shake correction unit 500 of FIG. 2A . When the detected part 1300 moves in the X-axis direction, the inductances of the first sensing coil L1 and the second sensing coil L2 increase or decrease in different directions. Therefore, when the detected part 1300 moves in the X-axis direction, the first oscillation signal Sosc1 and the second oscillation signal Sosc2 generated by the first sensing coil L1 and the second sensing coil L2, May be different from each other.

Referring to FIG. 6A, the frequency ranges of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 may be different from each other. For example, the highest frequency of the second oscillation signal Sosc2 in the low frequency region may be lower than the lowest frequency of the first oscillation signal Sosc1 in the high frequency region.

According to an embodiment of the present invention, two oscillation circuits disposed adjacent to each other generate oscillation signals in different frequency ranges, thereby eliminating interference between a plurality of oscillation signals. 6 (b), the frequency ranges of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 are the same and the first oscillation signal Sosc1, And the frequency of the second oscillation signal Sosc2 may intersect with each other at one point.

7 shows frequencies of a plurality of oscillation signals in accordance with movement of the detected part in the Y-axis direction according to an embodiment of the present invention.

In this embodiment, it is assumed that the first sensing coil L1 and the second sensing coil L2 correspond to at least one OIS sensing coil 530b, 530c included in the shake correction unit 500 of FIG. 2A . When the detected part 1300 moves in the Y-axis direction, the inductances of the first sensing coil L1 and the second sensing coil L2 increase or decrease in the same direction. Therefore, when the detected part 1300 moves in the Y axis direction, the first oscillation signal Sosc1 and the second oscillation signal Sosc2 generated by the first sensing coil L1 and the second sensing coil L2, The direction of change of the frequency of the frequency can be mutually the same.

Referring to FIG. 7, the frequency ranges of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 may be different from each other. On the other hand, the highest frequency of the second oscillation signal Sosc2 in the low frequency region may be higher than the lowest frequency of the first oscillation signal Sosc1 in the high frequency region. That is, the frequencies of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 may overlap in a certain frequency range.

Although the frequencies of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 overlap in a certain frequency range, the directions of change in the frequencies of the first oscillation signal Sosc1 and the second oscillation signal Sosc2 are different from each other So that interference between a plurality of oscillation signals can be eliminated.

On the other hand, in the above-described embodiment, the frequency ranges of at least two oscillation signals generated in the actuator of the focus adjustment unit are different from each other, or the frequency ranges of at least two oscillation signals generated in the actuator of the shake correction unit are different from each other The frequency range of at least two oscillation signals generated in the actuator of the focus adjustment unit may be different from the frequency range of at least two oscillation signals generated in the actuator of the shake correction unit.

In other words, the focus adjustment unit and the shake correction unit generate oscillation signals of different frequency ranges, thereby eliminating frequency interference between the lens barrel or the position detection operation of the to-be-detected portion performed in each of the focus adjustment unit and the shake correction unit, , It is possible to secure the reliability of the position detecting operation.

In the above description, the operation for determining the position of the magnet is described on the assumption that two sensing coils are provided. However, at least two sensing coils may be provided, and for the sensing coils having at least two sensing coils, It goes without saying that one scheme can be applied.

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 limited to the disclosed exemplary embodiments, but, on the contrary, Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Therefore, the spirit of the present invention should not be construed as being limited to the above-described embodiments, and all of the equivalents or equivalents of the claims, as well as the following claims, I will say.

110: Case
120: Housing
210: lens barrel
300: Carrier
310: frame
320: Lens holder
400: Focus adjustment unit
500: shake correction unit
600: substrate
700: Image sensor module
1000: Actuator
1100:
1200: drive coil
1300: Magnet
1400:
1410:
1410a: first oscillation circuit
1410b: second oscillation circuit
1430:
1450:

Claims (15)

A detected part; And
A position detection unit disposed opposite to the detected part and including at least two sensing coils each forming at least two oscillation circuits; Lt; / RTI >
Wherein the position detection unit detects the position of the to-be-detected portion in accordance with at least two oscillation signals generated in the at least two oscillation circuits and having different frequency ranges.
The position detecting apparatus according to claim 1,
And detects a displacement of the detected portion in a direction perpendicular to a plane on which the at least two sensing coils are arranged.
3. The method of claim 2,
Wherein the frequencies of the at least two oscillation signals are increased or decreased in the same direction in accordance with movement of the to-be-detected portion.
The position detecting apparatus according to claim 1,
And detects the displacement of the to-be-detected portion in the arrangement direction of the at least two sensing coils.
3. The method of claim 2,
Wherein frequencies of the at least two oscillation signals are increased or decreased in different directions according to movement of the to-be-detected portion.
The method according to claim 1,
Wherein one of the at least two oscillation circuits generates the oscillation signal in the low frequency region and the other generates the oscillation signal in the high frequency region.
The method according to claim 6,
Wherein the highest frequency of the oscillation signal of the low frequency region is lower than the lowest frequency of the oscillation signal of the high frequency region.
2. The circuit of claim 1, wherein each of the at least two oscillating circuits comprises:
Further comprising a capacitor for implementing each of said at least two sensing coils and a predetermined oscillator.
9. The method of claim 8,
Wherein a frequency range of the at least two oscillation signals is determined according to an inductance of a sensing coil provided in each of at least two oscillation circuits and a capacitance of the capacitor.
10. The method of claim 9,
Wherein an inductance of a sensing coil provided in one of the at least two oscillation circuits is different from an inductance of a sensing coil provided in another oscillation circuit.
10. The method of claim 9,
Wherein a capacitance of a capacitor provided in one oscillation circuit of the at least two oscillation circuits is different from a capacitance of a capacitor provided in another oscillation circuit.
Lens barrel;
A focus adjusting unit for providing a driving force in a direction of an optical axis of the lens barrel; And
A shake correcting unit for providing a driving force in two directions perpendicular to the optical axis; Lt; / RTI >
Wherein each of the focus adjustment unit and the shake correction unit generates an oscillation signal whose frequency changes according to the movement of the lens barrel to detect a displacement of the lens barrel,
Wherein the frequency range of the oscillation signal generated by the focus adjustment unit is different from the frequency range of the oscillation signal generated by the shake correction unit.
13. The apparatus according to claim 12,
Wherein at least two oscillation signals vary in frequency as the lens barrel moves, and the frequency ranges of the at least two oscillation signals are different.
13. The apparatus according to claim 12,
Wherein at least two oscillation signals vary in frequency as the lens barrel moves, and the frequency ranges of the at least two oscillation signals are different.
13. The method of claim 12,
Wherein each of the focus adjustment unit and the shake correction unit includes an oscillation circuit for generating the oscillation signal.

Images