Patent Publication Number: US-2023161225-A1

Title: Camera actuator and camera module including same

Description:
TECHNICAL FIELD 
     An embodiment relates to a camera actuator and a camera module. 
     BACKGROUND ART 
     A camera module captures a subject and stores it as an image or video, and is installed in various devices such as mobile terminals such as cell phones, laptops, drones, and vehicles. 
     In general, the device described above is equipped with a miniature camera module, and the camera module can perform an autofocus (AF) function of automatically adjusting the distance between the image sensor and the lens to align the focal lengths of the lenses. In addition, the camera module may perform a zooming function of zooming up or zooming out by increasing or decreasing the magnification of a distant subject through a zoom lens. 
     Meanwhile, a zoom actuator is used for a zooming function in the camera module. However, friction torque is generated when the lens is moved due to the mechanical movement of the actuator, and problems such as a decrease in driving force, an increase in power consumption, and a decrease in control characteristics occur due to the friction torque. 
     In particular, in order to derive the optical properties, not only alignment between a plurality of lens groups but also alignment of a plurality of lens groups with the image sensor must be well matched. However, when the center of the spherical surface between the lens groups deviates from the optical axis, tilt, which is a lens inclination phenomenon, or a phenomenon that the central axis of the lens group and the image sensor is not aligned, there is a problem in that the image quality or resolution is deteriorated because the angle of view is changed or the focus is out of focus. 
     In addition, when increasing the separation distance in a region where friction is generated to reduce friction torque resistance when moving the lens for the zoom function in the camera module, there is a technical problem in that a lens decent or a lens tilt is deepened when the zoom movement or the zoom movement is reversed. 
     In addition, recent camera modules employ image stabilization (IS) technology to correct or prevent image stabilization due to camera movement caused by an unstable fixing device or a user’s movement. 
     Such image stabilization (IS) technology includes an optical image stabilizer (OIS) technology and an image stabilization prevention technology using an image sensor. Here, OIS technology is a technology that corrects motion by changing the path of light, and the image stabilization prevention technology using the image sensor is a technology that compensates for motion in both mechanical and electronic ways, and recently, OIS technology is being adopted more and more. 
     Meanwhile, the camera module may include a reflective member, a driving unit, etc. that can change the path of light to implement the OIS function. The reflective member may be tilted by a driving force applied from the driving unit, and a path of light may be changed during this process. For example, when the camera module detects a hand-shake vibration waveform generated by a user, the reflective member may tilt to compensate for the hand-shake vibration waveform. However, there is a problem in that a relatively small vibration waveform is generated or a deviation occurs between the hand-shake vibration waveform caused by problems such as noise and sync of components and a waveform compensating for the vibration waveform. However, when a relatively small vibration waveform occurs or problems such as noise and sync of components occur, there is a problem in that there is a deviation between the hand-shake vibration waveform caused by such a problem and the waveform that compensates for it. In this case, the optical characteristics of the camera module may be deteriorated, and there is a problem that the effect of the OIS function is insignificant. 
     Therefore, a new camera module capable of solving the above problems is required. 
     DISCLOSURE 
     Technical Problem 
     An embodiment provides a camera actuator and a camera module having improved optical properties. 
     In addition, the embodiment provides a camera actuator and a camera module that can effectively control the vibration generated by hand shake. 
     In addition, the embodiment provides a camera actuator and a camera module having improved autofocus and high magnification zoom functions. 
     In addition, the embodiment provides a camera actuator and a camera module capable of preventing problems such as de-centering, tilting, friction, etc. occurring when the lens group is moved. 
     Technical Solution 
     A camera actuator according to an embodiment may include a housing; a prism unit disposed in the housing; and a first driving unit for tilting the prism unit; wherein the prism unit includes: the prism; and a prism mover disposed to surround the prism, and a second driving unit disposed between the prism and the prism mover and tilting the prism, and wherein a driving displacement of the second driving unit may be is smaller than a driving displacement of the first driving unit. 
     In addition, the second driving unit includes a plurality of piezoelectric devices, wherein the prism mover includes an inner surface facing one side surface of the prism and inclined at a predetermined angle, and wherein the plurality of piezoelectric devices may be is disposed on the inner surface of the prism mover. 
     In addition, the first driving unit includes a plurality of sub driving units including a coil unit and a magnet, wherein the plurality of sub driving units includes: a first sub driving unit facing a first outer surface of the prism mover; a second sub driving unit facing a second outer surface of the prism mover; and a third sub driving unit facing a lower surface of the prism mover, wherein the first and second sub driving units face each other in a first direction, and wherein the third sub driving unit may face the prism unit in a second direction perpendicular to the first direction. 
     In addition, the first driving unit may be provided to rotate the prism unit in the second direction with a virtual first line formed by the first and second sub driving units in the first direction as an axis. 
     In addition, the first driving unit may be provided to rotate the prism unit in the first direction with a virtual second line formed by the third and fourth sub driving units in the second direction as an axis. 
     In addition, the plurality of piezoelectric devices may include first and second piezoelectric devices spaced apart from each other in the second direction; and third and fourth piezoelectric devices spaced apart from each other in the first direction. 
     In addition, the prism may be provided to be rotationally movable in the second direction by at least one of the first and second piezoelectric devices on the prism mover. 
     In addition, the prism may be provided to be rotatably movable in the first direction by at least one of the third and fourth piezoelectric devices on the prism mover. 
     In addition, the second driving unit includes: a circuit board disposed on the inner surface of the prism mover; and a base layer disposed on the circuit board and including a plurality of openings, and wherein the plurality of piezoelectric devices may be respectively disposed in the plurality of openings. 
     In addition, the base layer may include an elastically deformable material. 
     In addition, a thickness of the plurality of piezoelectric devices may be greater than or equal to a thickness of the base layer. 
     In addition, the camera module according to the embodiment includes a first camera actuator and a second camera actuator, wherein the first camera actuator performs an auto focusing or zoom function, the second camera actuator performs an OIS (Optical Image Stabilizer) function, and wherein the first camera actuator may include the camera actuator. 
     In addition, light incident on the camera module from an outside may be incident on the first camera actuator through the second camera actuator. 
     Advantageous Effects 
     The camera actuator and the camera module according to the embodiment may effectively control vibration caused by hand shake. In detail, the embodiment may include a first driving unit capable of tilting the prism unit to a first axis or a second axis. In addition, the embodiment further includes a second driving unit for driving with a driving displacement smaller than that of the first driving unit, wherein the second driving unit can tilt the prism disposed on the prism unit to a first axis or a second axis. In this case, the second driving unit may be driven by a driving displacement corresponding to a deviation occurring between the hand-shake vibration and the driving of the first driving unit. That is, the second driving unit can be driven as much as the driving displacement corresponding to the deviation caused by noise and sync of the first driving unit, and accordingly, it is possible to effectively control vibrations caused by hand shake, and thus have improved optical properties. 
     In addition, the camera actuator and the camera module according to the embodiment may have improved optical properties. In detail, in the camera actuator and camera module according to the embodiment, the driving unit for moving the lens group includes a piezoelectric device, and the driving unit can more precisely control the lens group. In addition, the camera actuator and the camera module according to the embodiment may minimize friction generated when the lens group is moved. Accordingly, the embodiment may provide more improved autofocus and zoom functions. 
    
    
     
       DESCRIPTION OF DRAWINGS 
         FIG.  1    is a perspective view of a camera module according to an embodiment. 
         FIG.  2    is a perspective view in which some components are omitted from the camera module according to the embodiment. 
         FIG.  3    is an exploded perspective view of a first camera actuator according to an embodiment. 
         FIG.  4    is a view of a first driving unit of a first camera actuator according to an embodiment. 
         FIG.  5    is a view of a first housing of a first camera actuator according to an embodiment. 
         FIGS.  6  and  7    are views of a prism unit of a first camera actuator according to an embodiment. 
         FIG.  8    is an exemplary view illustrating an operation of a first driving unit in a first camera actuator according to an embodiment. 
         FIGS.  9  to  11    are views of a second driving unit of the first camera actuator according to an embodiment. 
         FIG.  12    is an exemplary view illustrating an operation of a second driving unit in a first camera actuator according to an embodiment. 
         FIG.  13    is a graph of OIS implementation according to first and second driving units in the first camera actuator according to the embodiment. 
         FIG.  14    is an exploded perspective view of a second camera actuator according to an embodiment. 
         FIG.  15    is a cross-sectional view of a second camera actuator according to an embodiment. 
         FIG.  16    is a front view of a second camera actuator according to an embodiment. 
         FIG.  17    is a perspective view illustrating third and fourth driving units disposed in a housing of a second camera actuator according to an embodiment. 
         FIG.  18    is an exploded perspective view of a third driving unit according to an embodiment. 
         FIG.  19    is an exploded perspective view of a fourth driving unit according to an embodiment. 
         FIG.  20    is a perspective view of a partial configuration of a second camera actuator according to an embodiment. 
         FIG.  21    is a perspective view of a mobile terminal to which a camera module according to an embodiment is applied. 
         FIG.  22    is a perspective view of a vehicle to which a camera module according to an embodiment is applied. 
     
    
    
     MODES OF THE INVENTION 
     Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 
     However, the spirit and scope of the present invention is not limited to a part of the embodiments described, and may be implemented in various other forms, and within the spirit and scope of the present invention, one or more of the elements of the embodiments may be selectively combined and substituted for use. 
     In addition, unless expressly otherwise defined and described, the terms used in the embodiments of the present invention (including technical and scientific terms may be construed the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, and the terms such as those defined in commonly used dictionaries may be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art. 
     Further, the terms used in the embodiments of the present invention are for describing the embodiments and are not intended to limit the present invention. In this specification, the singular forms may also include the plural forms unless specifically stated in the phrase, and may include at least one of all combinations that may be combined in A, B, and C when described in “at least one (or more) of A (and), B, and C”. 
     Further, in describing the elements of the embodiments of the present invention, the terms such as first, second, A, B, (a), and (b) may be used. These terms are only used to distinguish the elements from other elements, and the terms are not limited to the essence, order, or order of the elements. In addition, when an element is described as being “connected”, “coupled”, or “connected” to another element, it may include not only when the element is directly “connected” to, “coupled” to, or “connected” to other elements, but also when the element is “connected”, “coupled”, or “connected” by another element between the element and other elements. 
     In addition, when described as being formed or disposed “on (over)” or “under (below)” of each element, the “on (over)” or “under (below)” may include not only when two elements are directly connected to each other, but also when one or more other elements are formed or disposed between two elements. Further, when expressed as “on (over)” or “under (below)”, it may include not only the upper direction but also the lower direction based on one element. 
     An optical axis direction used below may be defined as an optical axis direction of a lens coupled to a camera actuator and a camera module, and a vertical direction may be defined as a direction perpendicular to the optical axis. 
     A autofocus function used below may be defined a function to automatically focus on the subject by adjusting the distance from the image sensor by moving the lens in the optical axis direction according to the distance of the subject so that a clear image of the subject can be obtained by the image sensor. 
     Meanwhile, the auto focus may correspond to auto focus (AF). In addition, closed-loop auto focus (CLAF) control may be defined as real-time feedback control of the lens position by sensing the distance between the image sensor and the lens to improve focus adjustment accuracy. 
     In addition, before the description of the embodiment of the invention, a first direction may mean a x-axis direction shown in the drawings, a second direction may be a different direction from the first direction. For example, the second direction may mean a y-axis direction shown in the drawing in a direction perpendicular to the first direction. Also, a third direction may be different from the first and second directions. For example, the third direction may mean a z-axis direction shown in the drawing in a direction perpendicular to the first and second directions. Here, the third direction may mean an optical axis direction. 
     Hereinafter, the configuration of the camera module according to the present embodiment will be described with reference to the drawings. 
       FIG.  1    is a perspective view of a camera module according to an embodiment, and  FIG.  2    is a perspective view in which some components are omitted from the camera module according to the embodiment. 
     Referring to  FIGS.  1  and  2   , the camera module  10  according to the embodiment may include one or a plurality of camera actuators. For example, the camera module  10  may include a first camera actuator  1000  and a second camera actuator  2000 , and a cover case  15  for protecting the first camera actuator  1000  and the second camera actuator  2000  may be included. 
     The first camera actuator  1000  may be an optical image stabilizer (OIS) actuator. In this case, the light incident on the camera module  10  from the outside may be preferentially incident on the first camera actuator  1000 . In addition, the light incident on the first camera actuator  1000  may be incident on the second camera actuator  2000  by changing the path of the light, and the light passing through the second camera actuator  2000  may be incident on the image sensor  2900 . 
     The second camera actuator  2000  may be a zoom and/or auto focus actuator. The second camera actuator  2000  may include a plurality of lenses. The second camera actuator  2000  may perform a zoom or autofocus function by moving at least one lens in the optical axis direction according to a control signal of a controller. 
       FIG.  3    is an exploded perspective view of a first camera actuator according to an embodiment, and  FIG.  4    is a view of a first driving unit of a first camera actuator according to an embodiment. In addition,  FIG.  5    is a view of a first housing of a first camera actuator according to an embodiment, and  FIGS.  6  and  7    are views of a prism unit of a first camera actuator according to an embodiment. 
     The first camera actuator  1000  according to the embodiment will be described in more detail with reference to  FIGS.  3  to  7   . 
     Referring to  FIG.  3   , the first camera actuator  1000  may include a cover member  100 , a first housing  200 , a first driving unit  300 , a prism unit  400 , and a second driving unit  500 . 
     The cover member  100  may include an accommodating space therein, and at least one side surface may be open. For example, the cover member  100  may have a structure in which a plurality of side surfaces connected to each other are opened. In detail, the cover member  100  may have a structure in which a front surface through which light is incident from the outside, a lower surface corresponding to the first camera actuator  1000 , and a rear surface opposite the front surface, and a light movement path of the prism unit  400 , which will be described later, may be provided. 
     The cover member  100  may include a rigid material. For example, the cover member  100  may include a material such as resin, metal, or ceramic, and may support the third housing  200  disposed in the accommodation space. For example, the cover member  100  is disposed to surround the first housing  200 , the third driving unit  300 , the prism unit  400 , and the like, and may support the components. 
     Referring to  FIG.  4   , the first driving unit  300  may include a first circuit board  310 , a coil unit  330 , and a magnet  350 . 
     The first circuit board  310  may be connected to a power source (not shown) to apply power to the coil unit  330 . The first circuit board  310  may include a circuit board having a wiring pattern that can be electrically connected, such as a rigid printed circuit board (Rigid PCB), a flexible printed circuit board (Flexible PCB), and a rigid flexible printed circuit board (Rigid Flexible PCB). 
     The coil unit  330  may be electrically connected to the first circuit board  310 . The coil unit  330  may include one or a plurality of coil units. For example, the coil unit  330  may include a first coil unit  331 , a second coil unit  332 , and a third coil unit  333 . 
     The first to third coil units  331 ,  332 , and  333  may be spaced apart from each other. For example, the first circuit board  310  may have a ‘C’ shape, and the first coil unit  331  and the second coil unit  332  may be respectively disposed on first and second surfaces of the first circuit board  310  facing each other. Also, the third coil unit  333  may be disposed on a third surface connecting the first and second surfaces of the first circuit board  310 . 
     The magnet  350  may include one or a plurality of magnets. For example, the magnet  350  may include a first magnet  351 , a second magnet  352 , and a third magnet  353  disposed in a region corresponding to the coil unit  330 . In detail, the first magnet  351  may be disposed on the first surface of the first circuit board  310 . In detail, the first magnet  351  may be disposed on a region corresponding to the first coil unit  331 . Also, the second magnet  352  may be disposed on the second surface of the first circuit board  310 . The second magnet  352  may be disposed on a region corresponding to the second coil unit  332 . Also, the third magnet  353  may be disposed on the third surface of the first circuit board  310 . The third magnet  353  may be disposed on a region corresponding to the third coil unit  333 . 
     The first driving unit  300  may further include a sensing unit. For example, the first driving unit  300  may further include a Hall sensor and a gyro sensor (not shown). The Hall sensor may include a first Hall sensor HS 1  disposed adjacent to one coil unit selected from among the first coil unit  331  and the second coil unit  332 . The first Hall sensor HS 1  may detect a position of the first magnet  351 . In addition, the Hall sensor may include a second Hall sensor HS 2  disposed adjacent to the third coil unit  333 . The second Hall sensor HS 2  may detect a position of the third magnet  353 . 
     The first driving unit  300  may tilt the prism unit  400 . In detail, the first driving unit  300  may control the tilting of the prism unit  400  along a first axis or a second axis by applied power. 
     Referring to  FIG.  5   , the first housing  200  may include an accommodation space for accommodating the prism unit  400 . The first housing  200  may include a plurality of inner surfaces. For example, the first housing  200  may have a first inner surface  200 S 1  corresponding to the first surface of the first circuit board  310 , a second inner surface  200 S 2  corresponding to the second surface of the first circuit board  310 , and a third inner surface  200 S 3  corresponding to the third surface of the first circuit board  310 . 
     In detail, the first housing  200  may include a first inner surface  200 S 1  corresponding to the first coil unit  331  and a second inner surface  200 S 2  corresponding to the second coil unit  332 . The first inner surface  200 S 1  and the second inner surface  200 S 2  may be disposed to face each other in a first direction (x-axis direction). 
     In addition, the first housing  200  may further include a third inner surface  200 S 3  and a fourth inner surface  200 S 4 . The third inner surface  200 S 3  may be disposed in a region corresponding to the third coil unit  333 . The third inner surface  200 S 3  may be disposed between the first inner surface  200 S 1  and the second inner surface  200 S 2  to connect the two inner surfaces. The third inner surface  200 S 3  may have a shape extending in the first direction (x-axis direction). The fourth inner surface  200 S 4  may be disposed between the first inner surface  200 S 1  and the second inner surface  200 S 2  and may be connected to the third inner surface  200 S 3 . The fourth inner surface  200 S 4  may have a shape extending in the second direction (y-axis direction). 
     The first housing  200  may include a plurality of housing holes  210 . The housing hole  210  may be a through hole penetrating outer and inner surfaces of the first housing  200 . The plurality of housing holes  210  may include a first housing hole  211 , a second housing hole  212 , and a third housing hole  213 . The first housing hole  211  may be a through hole passing through an outer surface corresponding to the first inner surface  200 S 1 . The second housing hole  212  may be a through hole passing through an outer surface corresponding to the second inner surface  200 S 2 . The third housing hole  213  may be a through hole passing through an outer surface corresponding to the third inner surface  200 S 3 . 
     The first housing hole  211  may be disposed in a region corresponding to the first coil unit  331 . Also, the first housing hole  211  may have a size and shape corresponding to that of the first coil unit  331 . Accordingly, the first coil unit  331  may be disposed by being partially or entirely inserted into the first housing hole  211 . 
     The second housing hole  212  may be disposed in a region corresponding to the second coil unit  332 . Also, the second housing hole  212  may have a size and shape corresponding to that of the second coil unit  332 . Accordingly, the second coil unit  332  may be disposed by being partially or entirely inserted into the second housing hole  212 . 
     The third housing hole  213  may be disposed in a region corresponding to the third coil unit  333 . Also, the third housing hole  213  may have a size and shape corresponding to that of the third coil unit  333 . Accordingly, the third coil unit  333  may be disposed by being partially or entirely inserted into the third housing hole  213 . 
       FIGS.  6  and  7   , the prism unit  400  may be disposed in the first housing  200 . In detail, the prism unit  400  may be disposed in the accommodation space of the first housing  200 . 
     The prism unit  400  may include a prism  410  and a prism mover  430  disposed on the prism  410 . 
     The prism  410  may be a right-angle prism. The prism  410  may reflect the direction of light incident from the outside. That is, the prism  410  may change the path of the light incident to the first camera actuator  1000  from the outside toward the first camera actuator  1000 . 
     The prism mover  430  may be disposed on the prism  410 . The prism mover  430  may be disposed to surround the prism  410 . At least one side of the prism mover  430  may be open and may include an accommodating space therein. In detail, the prism mover  430  may have a structure in which a plurality of outer surfaces connected to each other are opened. For example, the prism mover  430  may have a structure in which an outer surface corresponding to the prism  410  is open, and may include an accommodation space defined as a first space  435  therein. The first space  435  may have a shape corresponding to the prism  410 . The first space  435  may have a larger volume than the prism  410 . Accordingly, the first space  435  may provide a space in which the prism  410  can be tilted. 
     The prism mover  430  may include an inner surface  435 S. The inner surface  2435 S may be an inner surface constituting the first space  2435 . The inner surface  435 S may be a surface facing one side surface of the prism  410 . The inner surface  435 S may be spaced apart from the one side surface of the prism  410 . For example, when the tilting control of the prism  410  is not controlled by the second driving unit  500 , the one side surface of the prism  410  may be spaced apart from the inner side  435 S. 
     The prism mover  430  may include a step  436 . The step  436  may be disposed in the first space  435 . The step  436  may serve as a guide and/or a seating part for the prism  410 . For example, a protrusion corresponding to the step  436  may be formed on an outside of the prism  410 . Accordingly, when the prism  410  is disposed on the prism mover  430 , the protrusion of the prism  410  may be guided by the step  436  of the prism mover  430  to be disposed in the first space  435 . That is, the prism mover  430  may arrange the prism  410  at a position set by the step  436  and effectively support the prism  410 . 
     In addition, the prism mover  430  may perform a stopper function of the prism  410 . For example, the prism  410  may be provided to be tiltable in the first and/or second axis directions on the prism mover  430  by a second driving unit  500  to be described later. In this case, the step  436  and the inner surface  435 S of the prism unit  400  may provide a stopper function when controlling the tilting of the prism  410 . 
     For example, when the prism  410  is tilted along the first axis on the prism unit  400 , the inner surface  435 S may prevent the prism  410  from tilting more than a threshold. In addition, when the prism  410  is tilted along the second axis on the prism unit  400 , the step  436  may prevent the prism from tilting more than a threshold. Accordingly, the prism  410  may have improved alignment characteristics and optical characteristics on the prism mover  430 , and may have improved reliability. 
     The prism unit  400  may include a plurality of outer surfaces. For example, the prism mover  430  may include a plurality of outer surfaces. The prism mover  430  may include a first outer surface  430 S 1  corresponding to the first inner surface  200 S 1  of the first housing  200 , a second outer surface  430 S 2  corresponding to the second inner surface  200 S 2 , a third outer surface  430 S 3  corresponding to the third inner surface  200 S 3 , and a fourth outer surface  430 S 4  corresponding to the fourth inner surface  200 S 4 . Here, the third outer surface  430 S 3  may be a lower surface of the prism mover  430 . 
     Also, the prism mover  430  may include a plurality of recesses. The recess may be a groove having a concave shape on the outer surface of the prism mover  430  in the direction of the first space  435 . The plurality of recesses may include a first recess  433 R 1 , a second recess  433 R 2 , and a third recess  433 R 3 . For example, the first recess  433 R 1  may be disposed on the first outer surface  430 S 1 . The first recess  433 R 1  may be disposed in a region corresponding to the first housing hole  211 . Also, the second recess  433 R 2  may be disposed on the second outer surface  430 S 2 . The second recess  433 R 2  may be disposed in a region corresponding to the second housing hole  212 . Also, the third recess  433 R 3  may be disposed on the third outer surface  430 S 3 . The third recess  433 R 3  may be disposed in a region corresponding to the third housing hole  213 . That is, the first housing hole  211  may correspond to the first coil unit  331 , and the second housing hole  212  may correspond to the second coil unit  332 . Also, the third housing hole  213  may correspond to the third coil unit  333 . 
     The magnet  350  may be disposed in the recess. For example, the first magnet  351  is in the first recess  433 R 1 , the second magnet  352  is in the second recess  433 R 2 , and the third magnet  353  is in the first recess  433 R 1 , and the magnets may be spaced apart from each other. 
       FIG.  8    is an exemplary view illustrating an operation of a first driving unit in a first camera actuator according to an embodiment. 
     Referring to  FIG.  8   , the prism unit  400  may be tilted to a first axis or a second axis by the first driving unit  300 . Here, the first axis tilting may mean tilting in an up-down direction (y-axis direction; second direction) with the x-axis direction shown in the drawing as a rotation axis, and the second axis tilting may mean tilting in a left-right direction (x-axis direction; first direction) with the y-axis direction shown in the drawing as the rotation axis. 
     The first driving unit  300  may include a plurality of sub driving units including the coil unit  330  and the magnet  350 . For example, the first driving unit  300  includes a first sub driving unit including the first coil unit  331  and the first magnet  351 , a second sub driving unit including the second coil unit  332  and the second magnet  352 , and a third sub driving unit including the third coil unit  333  and the third magnet  353 . The first sub driving unit may be disposed to face the first outer surface  430 S 1 , the second sub driving unit may be disposed to face the second outer surface  430 S 2 , and the third sub driving unit may be disposed to face the third outer surface  430 S 3 . The first sub driving unit may be disposed to face the second sub-driving unit in a first direction (x-axis direction). The third sub driving unit may be disposed to face the prism unit  400  in the second direction (y-axis direction). 
     The prism unit  400  may be tilted along a first axis. In detail, the first driving unit  300  may be provided such that the prism unit  400  can be rotated about a first virtual line L 1  formed by the first magnet  351 , the first coil unit  331 , the second magnet  352 , and the second coil unit  332  as an axis. Here, the first line L 1  may be a line extending in the first direction (x-axis direction). The first line L 1  may overlap the center of the prism  410  in the first direction. 
     That is, the third sub driving unit may rotate and move the prism unit  400   in an up-down direction (y-axis direction) with the first line L 1  as an axis. 
     For example, a repulsive force may be generated between the third coil unit  333  and a third-first magnet of the third magnet  353 , and an attractive force may be generated between the third coil unit  333  and a third-second magnet of the third magnet  353 . Here, the third-first magnet and the third-second magnet may face each other in a third direction (z-axis direction). In this case, the prism unit  400  may be tilted in an upper direction (refer to  FIG.  8   ) by the generated electromagnetic force. 
     In addition, an attractive force may be generated between the third coil unit  333  and the third-first magnet of the third magnet  353 , and a repulsive force may be generated between the third coil unit  333  and the third-second magnet of the third magnet  353 . In this case, the prism unit  400  may be tilted in a downward direction (refer to  FIG.  8   ) by the generated electromagnetic force. 
     The prism unit  400  may be tilted along the second axis. In detail, the first driving unit  300  may be provided such that the prism unit  400  can be rotated about the second virtual line L 2  formed by the third magnet  353  and the third coil unit  333  as an axis. Here, the second line L 2  may be a line extending in the second direction (y-axis direction). The second line L 2  of the prism  410  may overlap the center of the prism  410  in the second direction. 
     That is, the first and second sub driving units may rotate and move the prism unit  400  in a left-right direction (x-axis direction) about the second line L 2  as an axis. 
     For example, a repulsive force may be generated between the first coil unit  331  and a first-first magnet of the first magnet  351 , and an attractive force may be generated between the first coil unit  331  and a first-second magnet of the first magnet  351 . In addition, an attractive force may be generated between the second coil unit  332  and a second-first magnet of the second magnet  352 , and a repulsive force may be generated between the second coil unit  332  and a second-second magnet of the second magnet  352 . Here, the first-first magnet and the second-first magnet may face each other in a first direction, and the first-second magnet and the second-second magnet may face each other in a first direction. In this case, the prism unit  400  may be tilted in the left direction (refer to  FIG.  8   ) by the generated electromagnetic force. 
     In addition, an attractive force may be generated between the first coil unit  331  and the first-first magnet of the first magnet  351 , and a repulsive force may be generated between the first coil unit  331  and the first-second magnet of the first magnet  351 . In addition, a repulsive force may be generated between the second coil unit  332  and the second-first magnet of the second magnet  352 , and an attractive force may be generated between the second coil unit  332  and the second-second magnet of the second magnet  352 . In this case, the prism unit  400  may be tilted in the right direction (refer to  FIG.  8   ) by the generated electromagnetic force. 
     That is, the first camera actuator  1000  according to the embodiment includes a VCM (Voice Coil Motor) type first driving unit  300 , and an optical image stabilizer (OIS) may be implemented by controlling the movement path of the incident light to the first axis and/or the second axis by the first driving unit  300 . In this case, the first camera actuator  1000  may have improved optical properties by minimizing the occurrence of a decent and a tilt phenomenon when implementing OIS. However, the embodiment is not limited thereto, and the first driving unit  300  may include a piezoelectric device, for example, a piezo-electric device or a shape memory alloy. In this case, the first driving unit  300  may tilt the prism unit  400  using a physical change of a piezoelectric device or a shape memory alloy, and may control a movement path of the incident light. 
       FIGS.  9  to  11    are views of a second driving unit of the first camera actuator according to an embodiment. 
     Referring to  FIGS.  9  to  11   , the first camera actuator  1000  according to the embodiment may include a second driving unit  500 . The second driving unit  500  may be disposed on the prism unit  400 . For example, the second driving unit  500  may be disposed on the prism mover  430 . The second driving unit  500  may be disposed between the prism  410  and the prism mover  430 . In detail, the second driving unit  500  may be disposed on an inner surface  435 S of the prism mover  430 . That is, the second driving unit  500  may be disposed to face one side surface of the prism  410  on the inner surface  435 S inclined at a predetermined angle. The inclination angle of the inner surface  435 S may correspond to an inclination angle of one side surface of the prism  410 . 
     The second driving unit  500  may include a second circuit board  510 , a base layer  520 , and a piezoelectric device  530 . 
     The second circuit board  510  may be disposed on the inner surface  435 S of the prism mover  430 . A plan area of the second circuit board  510  may be smaller than a plan area of the inner surface  435 S. Power may be applied to the plurality of piezoelectric devices  530 . The second circuit board  510  may include a circuit board having a wiring pattern that can be electrically connected, such as a rigid printed circuit board (Rigid PCB), a flexible printed circuit board (Flexible PCB), and a rigid flexible printed circuit board (Rigid Flexible PCB). 
     The base layer  520  may be disposed on the inner surface  435 S of the prism mover  430 . The base layer  520  may be disposed on the second circuit board  510 . The base layer  520  may be disposed in direct contact with an upper surface of the second circuit board  510 . The base layer  520  may have a predetermined thickness and may include a soft and elastic material. For example, the base layer  520  may include at least one of silicones, thermoplastic resins, thermoplastic silicone resins, thermoplastic elastomers, polyurethane elastomers, ethylene vinyl acetate (EVA), harmless plasticizers, and polyvinyl chloride (PVC) material with added stabilizer. The base layer  520  may be elastically deformed by the prism  410 . For example, the prism  410  may be tilted by a piezoelectric device  530  to be described later. In this process, the prism  410  may press a partial region of the base layer  520 , and the partial region of the base layer  520  may be elastically deformed by the pressure. In addition, when a driving force is removed from the prism  410  to return to an original position, the partial region of the base layer  520  may be elastically restored. 
     The base layer  520  may include an opening. The opening may be a through hole penetrating upper and lower surfaces of the base layer  520 . Here, the upper surface of the base layer  520  may be a surface facing one side surface of the prism  410 , and the lower surface of the base layer  520  may be a surface facing the second circuit board  510 . The opening may expose an upper surface of the second circuit board  510 . 
     A plurality of the openings may be disposed on the base layer  520 . In detail, a number of openings may correspond to a number of piezoelectric devices  530  to be described later. The plurality of openings may be spaced apart from each other. For example, the plurality of openings may include a first opening  521  and a second opening  522  spaced apart from each other in the second direction. Also, the plurality of openings may include a third opening  523  and a fourth opening  524  spaced apart from each other in the first direction. The third opening  523  and the fourth opening  524  may be disposed in a region between the first opening  521  and the second opening  522 . 
     The piezoelectric device  530  may be disposed on the inner surface  435 S of the prism mover  430 . The piezoelectric device  530  may be disposed on the second circuit board  510 . The piezoelectric device  530  may be electrically connected to the second circuit board  510 . In addition, the piezoelectric device  530  may be disposed in direct or indirect contact with the prism  410 . For example, the prism  410  may be physically coupled through an adhesive member (not shown) disposed between the upper surface of the piezoelectric device  530  and one side surface of the prism  410 . 
     The piezoelectric device  530  may include a material that causes mechanical deformation by applied power. The piezoelectric device  530  may include a piezo-electric device. The piezoelectric device  530  may include a ceramic material. For example, the piezoelectric device  530  may include at least one of ZnO, AlN, LiNbO4, lead antimony stannate, lead magnesium tantalate, lead nickel tantalate, titanates, tungstates, zirconates, or lead zirconate titanates [Pb(ZrxTi1-x)O3(PZT)], lead lanthanum zirconate titanate (PLZT), lead niobium zirconate titanate (PNZT), BaTiO3, SrTiO3, lead magnesium niobate, lead nickel niobate, lead manganese niobate, lead zinc niobate, lead, barium and bismuth, including lead titanate, and niobates of strontium. 
     A plurality of piezoelectric devices  530  may be disposed on the second circuit board  510 . The plurality of piezoelectric devices  530  may be respectively disposed in the opening of the base layer  520 . For example, the plurality of piezoelectric devices  530  may include a first piezoelectric device  531 , a second piezoelectric device  532 , a third piezoelectric device  533 , and a fourth piezoelectric device  534  spaced apart from each other. The first piezoelectric device  531  may be disposed in the first opening  521  of the base layer  520 . Also, the second piezoelectric device  532  may be disposed in the second opening  522  of the base layer  520 . Also, the third piezoelectric device  533  may be disposed in the third opening  523  of the base layer  520 . Also, the fourth piezoelectric device  534  may be disposed in the fourth opening  524  of the base layer  520 . 
     That is, the first piezoelectric device  531  and the second piezoelectric device  532  may be disposed to be spaced apart from each other in the second direction. Also, the third piezoelectric device  533  and the fourth piezoelectric device  534  may be disposed to be spaced apart from each other in the first direction. The third piezoelectric device  533  and the fourth piezoelectric device  534  may be disposed in a region between the first piezoelectric device  531  and the second piezoelectric device  532 . 
     The first piezoelectric device  531  may have the same shape and height as the second piezoelectric device  532 . In addition, the third piezoelectric device  533  may have the same shape and height as the fourth piezoelectric device  534 . Also, the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may have the same height. 
     The first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may have a planar shape corresponding to each of the first to fourth openings  521 ,  522 ,  523 , and  524 . In addition, the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may have a width corresponding to each of the first to fourth openings  521 ,  522 ,  523 , and  524 . 
     In addition, the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may have a thickness greater than or equal to a depth of each of the first to fourth openings  521 ,  522 ,  523  and  524 . That is, the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may be thicker than the base layer  520  or have the same thickness as the base layer  520 . 
     For example, when the thickness of the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  is the same as the depth of the first to fourth openings  521 ,  522 ,  523  and  524 , the upper surfaces of the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may be disposed on the same plane as the upper surface of the base layer  520  as shown in  FIG.  10   . Accordingly, when no driving force is applied to the prism  410 , the upper surface of the base layer  520  and the piezoelectric device  530  may be disposed in contact with one side surface of the prism  410 . 
     In addition, when the thickness of the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  is greater than the depth of the first to fourth openings  521 ,  522 ,  523  and  524 , the upper surfaces of the first to fourth piezoelectric devices  531 ,  532 ,  533 , and  534  may be disposed above the upper surface of the base layer  520 . Accordingly, when no driving force is applied to the prism  410 , the piezoelectric device  530  may be disposed in contact with one side surface of the prism  410  and may be spaced apart from the upper surface of the base layer  520  by a predetermined distance. 
       FIG.  12    is an exemplary view illustrating an operation of a second driving unit in a first camera actuator according to an embodiment. 
     Referring to  FIG.  12   , the piezoelectric device  530  may be mechanically deformed by applied power. In detail, the piezoelectric device  530  may expand or contract when a set power is applied. For example, the piezoelectric device  530  may expand toward one side surface of the prism  410  or contract in an opposite direction. The piezoelectric device  530  may expand or contract in the optical axis direction. 
     In this process, the piezoelectric device  530  of the second driving unit  500  may tilt the prism  410 . In detail, the piezoelectric device  530  may control the tilting of the prism  410  in a first axis or a second axis by an applied power. 
     For example, the prism  410  may be tilted along the first axis on the prism mover  430 . The prism  410  may be rotated in an up-down direction (refer to  FIG.  12   ) with the first line L 1  as an axis by the piezoelectric device  530 . The prism  410  may be rotated in an up-down direction (y-axis direction) by at least one of the first piezoelectric device  531  and the second piezoelectric device  532 . 
     In detail, the first piezoelectric device  531  may expand by applied power. In addition, the second piezoelectric device  532  may be contracted by an applied power or maintain a set shape because no power is applied. Accordingly, the prism  410  may be tilted in a downward direction (refer to  FIG.  12   ) about the first line L 1  as an axis by mechanical deformation of the piezoelectric device  530 . Here, since power is not applied to the third piezoelectric device  533  and the fourth piezoelectric device  534 , deformation may not occur. Alternatively, the third piezoelectric device  533  and the fourth piezoelectric device  534  may be deformed by a predetermined power to provide a driving force for tilting the prism  410  in a downward direction. 
     Also, the second piezoelectric device  532  may expand by applied power. In addition, the first piezoelectric device  531  may be contracted by an applied power or maintain a set shape because no power is applied. Accordingly, the prism  410  may be tilted in an upward direction (refer to  FIG.  12   ) about the first line L 1  as an axis by mechanical deformation of the piezoelectric device  530 . Here, since power is not applied to the third piezoelectric device  533  and the fourth piezoelectric device  534 , deformation may not occur. Alternatively, the third piezoelectric device  533  and the fourth piezoelectric device  534  may be deformed by a predetermined power to provide a driving force for tilting the prism  410  in an upward direction. 
     The prism  410  may be tilted along the second axis on the prism mover  430 . The prism  410  may be rotated and moved in a left-right direction (refer to  FIG.  12   ) with the second line L 2  as an axis by the piezoelectric device  530 . The prism  410  may be rotated in a left-right direction (x-axis direction) by at least one of the third piezoelectric device  533  and the fourth piezoelectric device  534 . 
     In detail, the third piezoelectric device  533  may expand by applied power. In addition, the fourth piezoelectric device  534  may be contracted by an applied power or maintain a set shape because no power is applied. Accordingly, the prism  410  may be tilted in the right direction (refer to  FIG.  12   ) about the second line L 2  as an axis by mechanical deformation of the piezoelectric device  530 . Here, since no power is applied to the first piezoelectric device  531  and the second piezoelectric device  532 , deformation may not occur. Alternatively, the first piezoelectric device  531  and the second piezoelectric device  532  may be deformed by a predetermined power to provide a driving force for tilting the prism  410  in the right direction. 
     Also, the fourth piezoelectric device  534  may expand by applied power. In addition, the third piezoelectric device  533  may be contracted by an applied power or maintain a set shape because no power is applied. Accordingly, the prism  410  may be tilted in a left direction (refer to  FIG.  12   ) about the second line L 2  as an axis by mechanical deformation of the piezoelectric device  530 . Here, since no power is applied to the first piezoelectric device  531  and the second piezoelectric device  532 , deformation may not occur. Alternatively, the first piezoelectric device  531  and the second piezoelectric device  532  may be deformed by a predetermined power to provide a driving force for tilting the prism  410  in the left direction. 
     That is, the first camera actuator  1000  according to the embodiment includes the second driving unit  500 , and the prism  410  may be tilted to a first axis or a second axis by the second driving unit  500 . Accordingly, the second driving unit  500  may minimize the deviation generated when the OIS is implemented by the first driving unit  300 . 
     In this case, a driving displacement of the second driving unit  500  may be smaller than a driving displacement of the first driving unit  300 . For example, the driving displacement of the second driving unit  500  may be about 30% or less of the driving displacement of the first driving unit  300 . 
     In detail, when the driving displacement of the second driving unit  500  exceeds about 30% of the driving displacement of the first driving unit  300 , the tilting angle of the prism  410  may be relatively large. That is, the range in which the prism  410  changes on the prism mover  430  is relatively large, so that the required size of the prism mover  430  may increase. In addition, when the driving displacement of the second driving unit  500  exceeds about 30% of the driving displacement of the first driving unit  300 , the coupling force between the prism  410  and the prism mover  430  may be reduced. Accordingly, the driving displacement of the second driving unit  500  preferably satisfies the above-described range. 
       FIG.  13    is a graph of OIS implementation according to first and second driving units in the first camera actuator according to the embodiment. In detail,  FIG.  13    is a graph of hand-shake vibration and waveforms of the first driving unit and the second driving unit. 
     The first camera actuator  1000  may effectively compensate for hand-shake vibration generated by the first driving unit  300  and the second driving unit  500 . 
     For example, as shown in  FIG.  13   , when a waveform is generated due to hand shake vibration, the first driving unit  300  may form a compensation waveform (master compensation angle in  FIG.  13   ) corresponding to the hand shake vibration waveform. However, as shown in  FIG.  13   , a deviation may occur between the hand-shake vibration waveform and the compensation waveform of the first driving unit  300 . For example, deviation due to noise of the first driving unit  300 , for example, noise of the coil unit  330 , noise of the hall sensors HS 1  and HS 2 , noise of the gyro sensor, driving sync of components, etc. may occur. 
     In this case, the second driving unit  500  may form a correction waveform (the master correction result of  FIG.  13   ) corresponding to the deviation. Here, the correction waveform may be a waveform for a difference between the hand-shake vibration waveform and the compensation waveform of the first driving unit  300 . That is, the second driving unit  500  may change with a smaller driving displacement than the first driving unit  300  in order to compensate for the minutely generated waveform. Accordingly, the first camera actuator  1000  may obtain a waveform according to the correction result waveform (the Master + Slave correction result of  FIG.  13   ). 
     That is, in the embodiment, the hand-shake vibration may be more effectively corrected by the second driving unit  500  driven by a driving displacement corresponding to a deviation between the hand-shake vibration and the first driving unit  300 . Accordingly, the first camera actuator  1000  may have improved optical characteristics when implementing OIS. 
       FIG.  14    is an exploded perspective view of a second camera actuator according to an embodiment, and  FIG.  15    is a cross-sectional view of a second camera actuator according to an embodiment. In addition,  FIG.  16    is a front view of a second camera actuator according to an embodiment, and  FIG.  17    is a perspective view illustrating third and fourth driving units disposed in a housing of a second camera actuator according to an embodiment. In addition,  FIGS.  18  and  19    are exploded perspective views of first and second driving units according to the embodiment, and  FIG.  20    is a perspective view of a partial configuration of a second camera actuator according to an embodiment. 
     Referring to  FIGS.  14  to  20   , the second camera actuator  2000  according to the embodiment may include a second housing  2100 , a first lens unit  2105 , a first lens barrel  2200 , a third driving unit  2300 , a second lens barrel  2400 , and a fourth driving unit  2500 . 
     The second housing  2100  may form an exterior of the second camera actuator  2000 . The second housing  2100  may have upper and lower partial regions open and may have a hexahedral shape. 
     The second housing  2100  may include an accommodating space therein. The first lens barrel  2200 , the third driving unit  2300 , the second lens barrel  2400 , and the fourth driving unit  2500  may be accommodated in the accommodating space of the second housing  2100 . 
     The second housing  2100  may include a first sub-housing  2110  and a second sub-housing  2120 . 
     The first sub-housing  2110  may include a first hole  2111 . The first hole  2111  may be formed on one side of the first sub-housing  2110 . The first hole  2111  is a hollow hole and may be a hole passing through outside and inside of the first sub-housing  2110 . 
     The first sub-housing  2110  may further include a second hole  2112  and a third hole  2113 . The second hole  2112  and the third hole  2113  may be disposed on one side of the first sub-housing  2110 . The second hole  2112  and the third hole  2113  may be hollow holes passing through the outside and the inside of the first sub-housing  2110 . The second hole  2112  and the third hole  2113  may be spaced apart from the first hole  2111 . In detail, the first hole  2111  may be disposed between the second hole  2112  and the third hole  2113 . The first hole  2111  may be disposed at equal intervals to the second hole  2112  and the third hole  2113 . 
     The second hole  2112  may include a plurality of protrusions protruding from an inner circumferential surface of the second hole  2112  toward the center of the second hole  2112 . For example, the plurality of protrusions may include a first protrusion  2112   a  disposed at an upper end of the second hole  2112  and a second protrusion  2112   b  disposed at a lower end of the second hole  2112  in the optical axis direction. 
     In detail, the first protrusion  2112   a  may include a plurality of first sub-protrusions (not shown) spaced apart from each other. The plurality of first sub-protrusions may be arranged at equal intervals from the center of the second hole  2112  along a circumference of a concentric circle shape. Also, the second protrusion  2112   b   may be spaced apart from the first protrusion  2112   a  in the optical axis direction. The second protrusion  2112   b  may be disposed below the first protrusion  2112   a . The second protrusion  2112   b  may include a plurality of second sub-protrusions (not shown) spaced apart from each other. The plurality of second sub-protrusions may be arranged at equal intervals from the center of the second hole  2112  along a circumference of a concentric circle shape. The first protrusion  2112   a  and the second protrusion  2112   b  may provide a space in which a portion of the third driving unit  2300  to be described later, for example, the first buffer member  2321  is disposed. 
     The third hole  2113  may include a plurality of protrusions protruding from an inner circumferential surface of the third hole  2113  toward the center of the third hole  2113 . The plurality of protrusions may include a third protrusion  2113   a  disposed at an upper end of the third hole  2113  and a fourth protrusion  2113   b  disposed at a lower end of the second hole  2112  with respect to the optical axis direction. 
     The third protrusion  2113   a  may include a plurality of third sub-protrusions (not shown) spaced apart from each other. The plurality of third sub-protrusions may be arranged at equal intervals from the center of the third hole  2113  along a circumference of a concentric circle shape. Also, the fourth protrusion  2113   b  may be spaced apart from the third protrusion  2113   a  in the optical axis direction. The fourth protrusion  2113   b  may include a plurality of fourth sub-protrusions (not shown) spaced apart from each other. The plurality of fourth sub-protrusions may be arranged at equal intervals from the center of the third hole  2113  along a circumference of a concentric circle shape. The third protrusion  2113   a  and the fourth protrusion  2113   b  may provide a space in which a portion of the fourth driving unit  2500  to be described later, for example, a third buffer member  2521  is disposed. 
     The second sub-housing  2120  may be disposed under the first sub-housing  2110 . In detail, the second sub-housing  2120  may be disposed under the first sub-housing  2110  in a third direction (z-axis, optical-axis direction). The second sub-housing  2120  may be disposed closer to an image sensor  2900  to be described later than the first sub-housing  2110 . The first lens barrel  2200 , the third driving unit  2300 , the second lens barrel  2400 , and the fourth driving unit  2500  may be disposed in the second sub-housing  2120 . 
     The second sub-housing  2120  may be coupled to the first sub-housing  2110 . For example, the first sub-housing  2110  and the second sub-housing  2120  may be coupled by a separate fastening member (not shown) such as a screw. In addition, the first sub-housing  2110  and the second sub-housing  2120  may be coupled to each other by physical coupling of coupling jaws and coupling grooves respectively formed therein. 
     The first lens unit  2105  may be disposed in the second housing  2100  and may include at least one lens. For example, the first lens unit  2105  may be disposed in the first sub-housing  2110 . In detail, the first lens unit  2105  may be disposed in the first hole  2111  of the first sub-housing  2110 . For example, the first lens unit  2105  may be coupled to the first sub-housing  2110  by a screw thread formed on an inner circumferential surface of the first hole  2111 . 
     The first lens barrel  2200  may be disposed in the second housing  2100 . The first lens barrel  2200  may be disposed in the second sub-housing  2120 . The first lens barrel  2200  may be disposed under the first lens unit  2105 . For example, the first lens barrel  2200  may be disposed below the first lens unit  2105  in the optical axis direction, and may be closer to the image sensor  2900  than the first lens unit  2105 . The first lens barrel  2200  may be coupled to the third driving unit  2300 . The first lens barrel  2200  may move in the second housing  2100  by the third driving unit  2300 . In detail, the first lens barrel  2200  may be moved in the optical axis direction by the third driving unit  2300 . 
     The first lens barrel  2200  may include a first barrel part  2210 , a second lens unit  2205 , a first guide part  2220 , and a first elastic part  2230 . 
     The first barrel part  2210  may be disposed in a region overlapping the optical axis and may have an open shape on one surface and the other surface. For example, the first barrel part  2210  may have a cylindrical shape in which one surface and the other surface are open. 
     The first barrel part  2210  may include the first through hole  2211 . The first through hole  2211  may be a through hole penetrating through one surface and the other surface of the first barrel part  2210 . Here, one surface of the first barrel part  2210  may be a surface facing the first lens unit  2105 , and the other surface may be a surface opposite to the one surface and facing the image sensor  2900 . 
     The second lens unit  2205  may be disposed on the first barrel part  2210 . In detail, the second lens unit  2205  may be disposed in the first through hole  2211 . For example, a screw line may be formed on an inner circumferential surface of the first through hole  2211 , and the second lens unit  2205  may be coupled to the first barrel part  2210  by the screw line. 
     The second lens unit  2205  may include at least one lens. The second lens unit  2205  may perform a zoom function. The second lens unit  2205  may move in the optical axis direction. In detail, the second lens unit  2205  may move in the optical axis direction with respect to the first lens unit  2105 . 
     The first guide part  2220  may extend outwardly from the first barrel part  2210 . For example, the first guide part  2220  may extend from the first barrel part  2210  in a direction perpendicular to the optical axis, for example, in a first direction (x-axis direction). 
     The first guide part  2220  may include a first upper surface  2221 , a first side surface  2222 , and a first lower surface  2223 . 
     The first upper surface  2221  may face an inner upper surface of the second housing  2100 . The first upper surface  2221  may face the inner upper surface of the second housing  2100  in the second direction (y-axis direction). The first upper surface  2221  may include a plurality of sub upper surfaces. In detail, the first upper surface  2221  may include a first sub upper surface  2221   a  and a second sub upper surface  2221   b  that is disposed lower than the first sub upper surface  2221   a  in a second direction (y-axis direction). That is, the second sub upper surface  2221   b  may be disposed adjacent to the first lower surface  2223  than the first sub upper surface  2221   a . At least one first fastening protrusion (not shown) may be disposed on the second sub upper surface  2221   b . The first fastening protrusion may have a shape protruding upward on the second sub upper surface  2221   b . The first fastening protrusion may be inserted into a first fixing groove (not shown) formed in a first elastic part  2230  to be described later. 
     Also, the first upper surface  2221  may include a first stepped surface  2225  disposed between the first sub upper surface  2221   a  and the second sub upper surface  2221   b . The first stepped surface  2225  may be connected to ends of the first sub upper surface  2221   a  and the second sub upper surface  2221   b . The first stepped surface  2225   may be defined as the first stepped portion  2225 . That is, the first upper surface  2221  may include the first sub upper surface  2221   a , the second sub upper surface  2221   b , and the first stepped portion  2225 , and may have a stepped structure. 
     The first lower surface  2223  may face an inner lower surface of the second housing  2100  to be described later. A first groove  223   h   1  may be disposed on the first lower surface  2223 . The first groove  223   h   1  may have a concave shape in a direction from the first lower surface  2223  to the first upper surface  2221 . A first magnetic scaler  2610 , which will be described later, may be disposed in the first groove  223   h   1 . 
     Also, a second groove  2223   h   2  may be disposed on the first lower surface  2223 . The second groove  2223   h   2  may be spaced apart from the first groove  223   h   1 . The second groove  2223   h   2  may be disposed in an edge region of the first lower surface  2223 . The second groove  2223   h   2  may provide a region in which a portion of the first elastic part  2230 , which will be described later, is disposed. In detail, the second groove  2223   h   2  may provide a region in which the first elastic part  2230  is mounted and fixed. 
     The first side surface  2222  may be disposed between the first upper surface  2221  and the first lower surface  2223 . In detail, the first side surface  2222  may be a surface connecting the first upper surface  2221  and the first lower surface  2223 . In more detail, the first side surface  2222  may be a surface connecting the second sub upper surface  2221   b  and the first lower surface  2223 . The first side surface  2222  may face a second inner surface of the second sub-housing  2120  to be described later. 
     A first recess  2222   h  may be disposed on the first side surface  2222 . The first recess  2222   h  may have a concave shape in a direction from the first side surface  2222  to the first barrel part  2210 . Also, the first recess  2222   h  may have a groove shape extending in the optical axis direction (z-axis direction). The first recess  2222   h  may have a V-shape when viewed from a front. 
     The first guide part  2220  may include a first insertion hole  2220   h   1 . The first insertion hole  2220   h   1  may be a hole passing through one surface and the other surface of the first guide part  2220 . Here, one surface of the first guide part  2220  may be a surface facing the first lens unit  2105 , and the other surface may be a surface opposite to the one surface and facing the image sensor  2900 . 
     A first pin  2250  may be disposed in the first insertion hole  2220   h   1 . The first pin  2250  may be disposed to pass through the first insertion hole  2220   h   1 . The first pin  2250  may have a shape extending in the optical axis direction (z-axis direction), and may have a length in the optical axis direction longer than that of the first lens barrel  2200 . The first pin  2250  may be coupled to at least one of the first sub-housing  2110  and the second sub-housing  2120 . The first lens barrel  2200  may move the first pin  2250  as a movement axis in the optical axis direction. Through this, the second lens unit  2205  disposed in the first lens barrel  2200  may perform a zoom function and/or an autofocus function. 
     The first elastic part  2230  may be disposed on the first guide part  2220 . For example, the first elastic part  2230  may be disposed on the first upper surface  2221 , the first lower surface  2223 , and the first side surface  2222  of the first guide part  2220 . The first elastic part  2230  may be coupled to the first guide part  2220 . 
     The first elastic part  2230  may include a first elastic member  2231  and a second elastic member  2232 . 
     The first elastic member  2231  may be coupled to the first guide part  2220 . The first elastic member  2231  may be disposed at a set position on the first side surface  2222 . 
     The first elastic member  2231  may have a shape corresponding to the first side surface  2222 . For example, the first elastic member  2231  may include a first region  2231   a , a second region  2231   b , and a third region  2231   c . 
     The first region  2231   a  and the second region  2231   b  may be disposed on the first side surface  2222  of the first guide part  2220  and may be spaced apart from each other. The first region  2231   a  and the second region  2231   b  may be disposed on a region of the first side surface  2222  in which the first recess  2222   h  is not disposed. 
     The third region  2231   c  may be disposed between the first region  2231   a  and the second region  2231   b  to connect the two regions  2231   a  and  2231   b . The third region  2231   c  may be disposed in a region corresponding to the first recess  2222   h . The third region  2231   c  may have a V-shape corresponding to the first recess  2222   h . 
     The second elastic member  2232  may be disposed on the first guide part  2220 . The second elastic member  2232  may be coupled to the first guide part  2220 . 
     The second elastic member  2232  may include a fourth region  2232   a , a fifth region  2232   b , and a sixth region  2232   c . 
     The fourth region  2232   a  may be disposed on the first upper surface  2221  of the first guide part  2220 . In detail, the fourth region  2232   a  may be disposed on the second sub upper surface  2221   b  of the first guide part  2220 . The fourth region may include a first fixing groove (not shown). The first fixing groove may be disposed in a region corresponding to the first fastening protrusion, and may have a shape corresponding to the first fastening protrusion. 
     The fifth region  2232   b  may be connected to the fourth region  2232   a . For example, the fifth region  2232   b  may be bent at one end of the fourth region  2232   a  and may be disposed on the first side surface  2222  of the first guide part  2220 . The fifth region  2232   b  may be disposed on the first elastic member  2231 . The fifth region  2232   b  may be parallel to the first region  2231   a  and the second region  2231   b . The fifth region  2232   b  may be disposed to cover the first elastic member  2231 . 
     The sixth region  2232   c  may be connected to the fifth region  2232   b . For example, the sixth region  2232   c  may be bent at one end of the fifth region  2232   b  and may be disposed on the first lower surface  2223  of the first guide part  2220 . A portion of the sixth region  2232   c  may be inserted into the second groove  2223   h   2  disposed on the first lower surface  2223 . 
     That is, the second elastic member  2232  may be physically coupled to the first guide part  2220  by inserting the sixth region  2232   c  into the second groove  2223   h   2  while the first fixing groove formed in the fourth region  2232   a  engages the first fastening protrusion. Accordingly, the first elastic part  2230  may maintain a state firmly coupled to the first guide part  2220 . 
     In addition, the first lens barrel  2200  may further include a first guide groove  2210   h   1 . The first guide groove  2210   h   1  may be disposed in a region extending outwardly from the first barrel part  2210 . The first guide groove  2210   h   1  may be disposed in a region corresponding to a second pin  2450  to be described later. The first guide groove  2210   h   1 may provide a space into which the second pin  2450  is inserted. The first lens barrel  2200  may move in the optical axis direction by the first pin  2250  and the second pin  2450 . In this case, the first guide groove  2210   h   1  may have an open shape at one side. For example, the first guide groove  2210   h   1  may have an open shape at one side facing the first inner surface of the second housing  2100 . Accordingly, friction and vibration generated when the first lens barrel  2200  is moved by the third driving unit  2300  may be minimized. 
     The second camera actuator  2000  may include a third driving unit  2300 . The third driving unit  2300  may be disposed in the second housing  2100 . The third driving unit  2300  may be coupled to the first lens barrel  2200 . The third driving unit  2300  may move the first lens barrel  2200  in the optical axis direction (z-axis direction). 
     The third driving unit  2300  may include a first piezoelectric device  2310 , a first extension bar  2320 , a first buffer member  2321 , and a second buffer member  2322 . 
     The first piezoelectric device  2310  may include a piezo-electric device. For example, the first piezoelectric device  2310  may include a material that causes mechanical deformation by applied power. The first piezoelectric device  2310  may contract or expand by applied power and may cause mechanical deformation in a set direction. For example, the first piezoelectric device  2310  may generate vibration while causing mechanical deformation in the optical axis direction (z-axis direction) by the applied power. 
     The first piezoelectric device  2310  may include a first disk part  2311  and a first protrusion  2512 . The first disk part  2311  may have a plate shape and may be disposed on the second hole  2112 . For example, the first disk part  2311  may be disposed on the first protrusion  2112   a  of the second hole  2112 . In detail, the first disk part  2311  may be disposed on the plurality of first sub-protrusions. The first protrusion  2112   a  may support the first disk part  2311 . 
     The first protrusion  2512  may be disposed under the first disk part  2311 . In detail, the first protrusion  2512  may be disposed under the first disc part  2311  in the third direction (z-axis direction) and may be connected to the first disc part  2311 . A portion of the first protrusion  2512  may be disposed in the second hole  2112 . The first protrusion  2512  may have a shape protruding toward the image sensor  2900 . A width (x-axis, y-axis direction) of the first protrusion  2512  may change toward the optical axis direction. For example, the width of the first protrusion  2512  may decrease as it approaches the image sensor  2900 . 
     The first extension bar  2320  may extend in the optical axis direction. The first extension bar  2320  may be disposed parallel to the optical axis and may be connected to the first piezoelectric device  2310 . For example, an upper end of the first extension bar  2320  may be connected to the first protrusion  2512 . In addition, a lower end of the first extension bar  2320  may be inserted into a lower end of the second housing  2100 , for example, a fourth hole (not shown) formed at the lower end of the second sub-housing  2120 . 
     In addition, one region of the first extension bar  2320  may be connected to the first lens barrel  2200 . For example, the first extension bar  2320  may be connected to the first lens barrel  2200  by the first elastic part  2230 . In detail, the first extension bar  2320  may be disposed between the first elastic member  2231  and the second elastic member  2232 . In more detail, the first extension bar  2320  may be disposed between the third region  2231   c  of the first elastic member  2231  and the fifth region  2232   b  of the second elastic member  2232 . The first extension bar  2320  may be fixed by the elastic force of the first elastic member  2231  and the second elastic member  2232 . 
     The first extension bar  2320  may transmit the vibration generated in the first piezoelectric device  2310  to the first lens barrel  2200 . The first lens barrel  2200  may move upward or downward (z-axis direction, optical-axis direction) according to the vibration direction of the first extension bar  2320 . Through this, the second lens unit  2205  in the first lens barrel  2200  may move to perform a zooming function of zooming up or zooming out. 
     The first buffer member  2321  may be disposed on the first extension bar  2320 . The first buffer member  2321  may be disposed on an upper region of the first extension bar  2320 . The first buffer member  2321  may be disposed in the second hole  2112  of the second housing  2100 . For example, the first buffer member  2321  may be disposed between the first protrusion  2112   a  and the second protrusion  2112   b  of the second hole  2112 . The first buffer member  2321  may be fixed to a position set by the first protrusion  2112   a  and the second protrusion  2112   b . In addition, the first buffer member  2321  may include a through hole into which the first extension bar  2320  is inserted. 
     The second buffer member  2322  may be disposed on the first extension bar  2320 . The second buffer member  2322  may be disposed on a lower region of the first extension bar  2320 . The second buffer member  2322  may be spaced apart from the first buffer member  2321  in the optical axis direction. The second buffer member  2322  may be disposed in a fourth hole (not shown) of the second housing  2100 . The second buffer member  2322  may be disposed to be inserted into the fourth hole. The second buffer member  2322  may include a through hole into which the first extension bar  2320  is inserted. 
     The first buffer member  2321  and the second buffer member  2322  may prevent noise caused by the vibration of the first extension bar  2320 . In addition, the first buffer member  2321  and the second buffer member  2322  may prevent the first extension bar  2320  from being deformed or damaged by an external impact. 
     The second lens barrel  2400  may be disposed in the second housing  2100 . The second lens barrel  2400  may be disposed in the second sub-housing  2120 . The second lens barrel  2400  may be disposed under the first lens barrel  2200 . For example, the second lens barrel  2400  may be disposed under the first lens barrel  2200  in the optical axis direction, and may be closer to the image sensor  2900  than the first lens barrel  2200 . The second lens barrel  2400  may be coupled to the fourth driving unit  2500 . The second lens barrel  2400  may move in the second housing  2100  by the fourth driving unit  2500 . In detail, the second lens barrel  2400  may be moved in the optical axis direction by the fourth driving unit  2500 . 
     The second lens barrel  2400  may include a second barrel part  2410 , a third lens unit  2405 , a second guide part  2420 , and a second elastic part  2430 . 
     The second barrel part  2410  may be disposed in a region overlapping the optical axis and may have an open shape on one surface and the other surface. For example, the second barrel part  2410  may have a cylindrical shape in which one surface and the other surface are open. 
     The second barrel part  2410  may include the second through hole  2411 . The second through hole  2411  may be a through hole penetrating through one surface and the other surface of the second barrel part  2410 . Here, one surface of the second barrel part  2410  may be a surface facing the first lens barrel  2200 , and the other surface may be a surface opposite to the one surface and facing the image sensor  2900 . 
     The third lens unit  2405  may be disposed on the second barrel part  2410 . In detail, the third lens unit  2405  may be disposed in the second through hole  2411 . For example, a screw line may be formed on an inner circumferential surface of the second through hole  2411 , and the third lens unit  2405  may be coupled to the second barrel part  2410  by the screw line. 
     The third lens unit  2405  may include at least one lens. The third lens unit  2405  may perform an auto focus function. The third lens unit  2405  may move in the optical axis direction. In detail, the third lens unit  2405  may move in the optical axis direction with respect to the first lens unit  2105 . The third lens unit  2405  may move separately from the second lens unit  2205 . Also, the distance at which the third lens unit  2405  can move in the optical axis direction may be the same as or different from that of the second lens unit  2205 . 
     The second guide part  2420  may extend outwardly from the second barrel part  2410 . For example, the second guide part  2420  may extend from the second barrel part  2410  in a direction perpendicular to the optical axis, for example, in a first direction (x-axis direction). In this case, the second guide part  2420  may extend in a direction opposite to the first guide part  2220 . For example, the first guide part  2220  may extend from the first barrel part  2210  in a +x-axis direction, and the second guide part  2420  may extend from the second barrel part  2410  in a -x-axis direction. 
     The second guide part  2420  may include a second lower surface  2421 , a second side surface  2422 , and a second upper surface  2423 . 
     The second upper surface  2423  may face an inner upper surface of the second housing  2100 . The second upper surface  2423  may face the inner upper surface of the second housing  2100  in the second direction (y-axis direction). A third groove  2423   h   1  may be disposed on the second upper surface  2423 . The third groove  2423   h   1  may have a concave shape in a direction from the second upper surface  2423  to the second lower surface  2421 . A second magnetic scaler  2620 , which will be described later, may be disposed in the third groove  2423   h   1 . 
     In addition, a fourth groove  2423   h   2  may be disposed on the second upper surface  2423 . The fourth groove  2423   h   2  may be spaced apart from the third groove  2423   h   1 . The fourth groove  2423   h   2  may be disposed in an edge region of the second upper surface  2423 . The fourth groove  2423   h   2  may provide a region in which a portion of the second elastic part  2430 , which will be described later, is disposed. In detail, the fourth groove  2423   h   2  may provide a region in which the second elastic part  2430  is mounted and fixed. 
     The second lower surface  2421  may face an inner lower surface of the second housing  2100 . The second lower surface  2421  may face the inner lower surface of the second housing  2100  in the second direction (y-axis direction). The second lower surface  2421  may include a plurality of sub lower surfaces. In detail, the second lower surface  2421  may include a first sub lower surface  2421   a  and a second sub-lower surface  2421   b  disposed above the first sub-lower surface  2421   a  in a second direction (y-axis direction). That is, the second sub lower surface  2421   b  may be disposed closer to the second upper surface  2423  than the first sub lower surface  2421   a . At least one second fastening protrusion (not shown) may be disposed on the second sub lower surface  2421   b . The second fastening protrusion may have a shape protruding downward from the second sub-lower surface  2421   b . The second fastening protrusion may be inserted into a second fixing groove (not shown) formed in a second elastic part  2430  to be described later. 
     Also, the second lower surface  2421  may include a second stepped surface  2425  disposed between the first sub lower surface  2421   a  and the second sub lower surface  2421   b . The second stepped surface  2425  may be connected to ends of the first sub-lower surface  2421   a  and the second sub-lower surface  2421   b . The second stepped surface  2425  may be defined as the second stepped portion  2425 . That is, the second lower surface  2421  may include the first sub lower surface  2421   a , the second sub lower surface  2421   b , and the second stepped portion  2425  and may have a stepped structure. 
     The second side surface  2422  may be disposed between the second upper surface  2423  and the second lower surface  2421 . In detail, the second side surface  2422  may be a surface connecting the second upper surface  2423  and the second lower surface  2421 . In more detail, the second side surface  2422  may be a surface connecting the second sub-lower surface  2421   b  and the second upper surface  2423 . The second side surface  2422  may face a first inner surface of the second sub-housing  2120  to be described later. 
     A second recess  2422   h  may be disposed on the second side surface  2422 . The second recess  2422   h  may have a concave shape from the second side surface  2422  toward the second barrel part  2410 . Also, the second recess  2422   h  may have a groove shape extending in the optical axis direction (z-axis direction). The second recess  2422   h  may have a V-shape when viewed from a front. 
     The second guide part  2420  may include a second insertion hole  2420   h   1 . The second insertion hole  2420   h   1  may be a hole passing through one surface and the other surface of the second guide part  2420 . Here, one surface of the second guide part  2420  may be a surface facing the first lens barrel  2200 , and the other surface may be a surface opposite to the one surface and facing the image sensor  2900 . 
     A second pin  2450  may be disposed in the second insertion hole  2420   h   1 . The second pin  2450  may be disposed to pass through the second insertion hole  2420   h   1 . The second pin  2450  may have a shape extending in the optical axis direction (z-axis direction). The second pin  2450  may be spaced apart from the first pin  2250  and may be parallel to the first pin  2250 . The second pin  2450  may have a length in the optical axis direction longer than that of the second lens barrel  2400 . The second pin  2450  may be coupled to at least one of the first sub-housing  2110  and the second sub-housing  2120 . The second lens barrel  2400  may move the second pin  2450  as a movement axis in the optical axis direction. Through this, the third lens unit  2405  disposed in the second lens barrel  2400  may perform a zoom function and/or an autofocus function. 
     The second elastic part  2430  may be disposed on the second guide part  2420 . For example, the second elastic part  2430  may be disposed on the second upper surface  2423 , the second lower surface  2421 , and the second side surface  2422  of the second guide part  2420 . The second elastic part  2430  may be coupled to the second guide part  2420 . 
     The second elastic part  2430  may include a third elastic member  2431  and a fourth elastic member  2432 . 
     The third elastic member  2431  may be coupled to the second guide part  2420 . The third elastic member  2431  may be disposed at a set position on the second side surface  2422 . 
     The third elastic member  2431  may have a shape corresponding to the second side surface  2422 . For example, the third elastic member  2431  may include a seventh region  2431   a , an eighth region  2431   b , and a ninth region  2431   c . 
     The seventh region  2431   a  and the eighth region  2431   b  may be disposed on the second side surface  2422  of the second guide part  2420  and may be spaced apart from each other. The seventh region  2431   a  and the eighth region  2431   b  may be disposed on a region of the second side surface  2422  in which the second recess  2422   h  is not disposed. 
     The ninth region  2431   c  may be disposed between the first region  2231   a  and the second region  2231   b  to connect the two regions  2431   a  and  2431   b . The ninth region  2431   c  may be disposed in a region corresponding to the second recess  2422   h . The ninth region  2431   c  may have a V-shape corresponding to the second recess  2422   h . 
     The fourth elastic member  2432  may be disposed on the second guide part  2420 . The fourth elastic member  2432  may be coupled to the second guide part  2420 . 
     The fourth elastic member  2432  may include a tenth region  2432   a , an eleventh region  2432   b , and a twelfth region  2432   c . 
     The tenth region  2432   a  may be disposed on the second lower surface  2421  of the second guide part  2420 . In detail, the tenth region  2432   a  may be disposed on the second sub lower surface  2421   b  of the second guide part  2420 . The tenth region  2431   a  may include a second fixing groove (not shown). The second fixing groove may be disposed in a region corresponding to the second fastening protrusion, and may have a shape corresponding to the second fastening protrusion. 
     The eleventh region  2432   b  may be connected to the tenth region  2432   a . For example, the eleventh region  2432   b  may be bent at one end of the tenth region  2432   a  and may be disposed on the second side surface  2422  of the second guide part  2420 . The eleventh region  2432   b  may be disposed on the third elastic member  2431 . The eleventh region  2432   b  may be parallel to the seventh region  2431   a  and the eighth region  2431   b . The eleventh region  2432   b  may be disposed to cover the third elastic member  2431 . 
     The twelfth region  2432   c  may be connected to the eleventh region  2432   b . For example, the twelfth region  2432   c  may be bent at one end of the eleventh region  2432   b  and may be disposed on the second upper surface  2423  of the second guide part  2420 . A portion of the twelfth region  2432   c  may be inserted into the fourth groove  2423   h   2  disposed on the second upper surface  2423 . 
     That is, the fourth elastic member  243  may be be physically coupled to the second guide part  2420  by inserting the twelfth region  2432   c  into the fourth groove  2423   h   2  while the second fixing groove formed in the seventh region  2431   a  engages the second fastening protrusion. Accordingly, the second elastic part  2430  may maintain a state firmly coupled to the second guide part  2420 . 
     In addition, the second lens barrel  2400  may further include a second guide groove  2410   h   1 . The second guide groove  2410   h   1  may be disposed in a region extending outwardly from the second barrel part  2410 . The second guide groove  2410   h   1  may be disposed in a region corresponding to the first pin  2250 . The second guide groove  2410   h   1  may provide a space into which the first pin  2250  is inserted. The second lens barrel  2400  may move in the optical axis direction by the first pin  2250  and the second pin  2450 . In this case, the second guide groove  2410   h   1  may have an open shape at one side. For example, the second guide groove  2410   h   1  may have an open shape at one side facing the second inner surface of the second housing  2100 . Accordingly, friction and vibration generated when the second lens barrel  2400  is moved by the fourth driving unit  2500  can be minimized. 
     The second camera actuator  2000  may include a fourth driving unit  2500 . The fourth driving unit  2500  may be disposed in the second housing  2100 . The fourth driving unit  2500  may be coupled to the second lens barrel  2400 . The fourth driving unit  2500  may move the second lens barrel  2400  in the optical axis direction (z-axis direction). 
     The fourth driving unit  2500  may include a second piezoelectric device  2510 , a second extension part  2520 , a third buffer member  2521 , and a fourth buffer member  2522 . 
     The second piezoelectric device  2510  may include a piezo-electric device. For example, the second piezoelectric device  2510  may include a material that causes mechanical deformation by applied power. The second piezoelectric device  2510  may contract or expand by applied power and may cause mechanical deformation in a set direction. For example, the second piezoelectric device  2510  may generate vibration while causing mechanical deformation in the optical axis direction (z-axis direction) by the applied power. 
     The second piezoelectric device  2510  may include a second disk part  2511  and a second protrusion  2512 . The second disk part  2511  has a plate shape and may be disposed on the third hole  2113 . For example, the second disk part  2511  may be disposed on the third protrusion  2113   a  of the third hole  2113 . In detail, the second disk part  2511  may be disposed on the plurality of third sub-protrusions. The third protrusion  2113   a  may support the second disc part  2511 . 
     The second protrusion  2512  may be disposed under the second disk part  2511 . In detail, the second protrusion  2512  may be disposed under the second disc part  2511  in the third direction (z-axis direction) and may be connected to the second disc part  2511 . A portion of the first protrusion  2512  may be disposed in the third hole  2113 . The second protrusion  2512  may have a shape protruding toward the image sensor  2900 . A width (x-axis, y-axis direction) of the second protrusion  2512  may change toward the optical axis direction. For example, the width of the second protrusion  2512  may decrease as it approaches the image sensor  2900 . 
     The second extension part  2520  may extend in the optical axis direction. The second extension part  2520  may be disposed parallel to the optical axis and may be connected to the second piezoelectric device  2510 . For example, an upper end of the second extension part  2520  may be connected to the second protrusion  2512 . Also, the lower end of the second extension part  2520  may be inserted into the lower end of the second housing  2100 , for example, a fifth hole (not shown) formed at the lower end of the second sub-housing  2120 . 
     In addition, one region of the second extension part  2520  may be connected to the second lens barrel  2400 . For example, the second extension part  2520  may be connected to the second lens barrel  2400  by the second elastic part  2430 . In detail, the second extension part  2520  may be disposed between the third elastic member  2431  and the fourth elastic member  2432 . In more detail, the second extension part  2520   may be disposed between the ninth region  2431   c  of the third elastic member  2431  and the eleventh region  2432   b  of the fourth elastic member  2432 . The second extension part  2520  may be fixed by the elastic force of the third elastic member  2431  and the fourth elastic member  2432 . 
     The second extension part  2520  may transmit the vibration generated in the second piezoelectric device  2510  to the second lens barrel  2400 . The second lens barrel  2400  may move upward or downward (z-axis direction, optical-axis direction) according to the vibration direction of the second extension part  2520 . Through this, the third lens unit  2405  in the second lens barrel  2400  may move to perform a zooming function of zooming up or zooming out. 
     The third buffer member  2521  may be disposed on the second extension part  2520 . The third buffer member  2521  may be disposed on an upper region of the second extension part  2520 . The third buffer member  2521  may be disposed in the third hole  2113  of the second housing  2100 . For example, the third buffer member  2521  may be disposed between the third protrusion  2113   a  and the fourth protrusion  2113   b  of the third hole  2113 . The third buffer member  2521  may be fixed to a position set by the third protrusion  2113   a  and the fourth protrusion  2113   b . In addition, the third buffer member  2521  may include a through hole into which the second extension part  2520  is inserted. 
     The fourth buffer member  2522  may be disposed on the second extension part  2520 . The fourth buffer member  2522  may be disposed on a lower region of the second extension part  2520 . The fourth buffer member  2522  may be spaced apart from the third buffer member  2521  in the optical axis direction. The fourth buffer member  2522  may be disposed in a fifth hole (not shown) of the second housing  2100 . The fourth buffer member  2522  may be disposed to be inserted into the fifth hole. The second buffer member  2322  may include a through hole into which the second extension part  2520  is inserted. 
     The third buffer member  2521  and the fourth buffer member  2522  may prevent noise caused by vibration of the second extension part  2520 . In addition, the third buffer member  2521  and the fourth buffer member  2522  may prevent the second extension part  2520  from being deformed or damaged by an external impact. 
     The second camera actuator  2000  may include a first magnetic scaler  2610 , a first sensing unit (not shown), a second magnetic scaler  2620 , and a second sensing unit (not shown). 
     The first magnetic scaler  2610  may be disposed on the first lens barrel  2200 . For example, the first magnetic scaler  2610  may be disposed on the first lower surface  2223 . In detail, the first magnetic scaler  2610  may be disposed in the first groove  223   h   1  of the first lens barrel  2200 . The first magnetic scaler  2610  may move along the optical axis direction together with the first lens barrel  2200 . 
     The first magnetic scaler  2610  may include a plurality of magnets. For example, the first magnetic scaler  2610  may have an N pole and an S pole alternately disposed in the optical axis direction. 
     The first sensing unit may be disposed adjacent to the first magnetic scaler  2610 . For example, the first sensing unit may be disposed to face the first magnetic scaler  2610  in a first direction (x-axis direction) or a second direction (y-axis direction). The first sensing unit may detect a position of the first magnetic scaler  2610 . Through this, the first sensing unit may detect the position and movement of the first lens barrel  2200  moving together with the first magnetic scaler  2610 . 
     The second magnetic scaler  2620  may be disposed on the second lens barrel  2400 . For example, the second magnetic scaler  2620  may be disposed on the second upper surface  2423 . In detail, the second magnetic scaler  2620  may be disposed in the third groove  2423   h   1  of the second lens barrel  2400 . The second magnetic scaler  2620  may move along the optical axis direction together with the second lens barrel  2400 . 
     The second magnetic scaler  2620  may include a plurality of magnets. For example, the second magnetic scaler  2620  may have an N pole and an S pole alternately disposed in the optical axis direction. 
     Also, the second sensing unit may be disposed adjacent to the second magnetic scaler  2620 . For example, the second sensing unit may be disposed to face the second magnetic scaler  2620  in a first direction (x-axis direction) or a second direction (y-axis direction). The second sensing unit may detect a position of the second magnetic scaler  2620 . Through this, the second sensing unit may detect the position and movement of the second lens barrel  2400  moving together with the second magnetic scaler  2620 . 
     Also, although not shown in the drawings, the second camera actuator  2000  according to the embodiment may further include a gyro sensor (not shown). The gyro sensor may be disposed in the second housing  2100 . The gyro sensor may detect a movement of a user using the camera actuator. 
     The second camera actuator  2000  according to the embodiment may include a second substrate  2800 . The second substrate  2800  may be disposed on the second housing  2100 . The second substrate  2800  may be disposed to surround a partial region of the second housing  2100 . For example, the second substrate  2800  may be disposed to surround a portion of the outer side of the second sub-housing  2120 . The second substrate  2800  may provide power or current to components disposed in the second housing  2100 . That is, the second substrate  2800  may be a circuit board, and may include a circuit board having a wiring pattern that can be electrically connected, such as a rigid printed circuit board (Rigid PCB), a flexible printed circuit board (Flexible PCB), and a rigid flexible printed circuit board (Rigid Flexible PCB). The second substrate  2800  may be electrically connected to the above-described first circuit board  310 . 
     The second substrate  2800  may include a first end  2810 . The first end  2810  may be disposed on the first piezoelectric device  2310  of the third driving unit  2300 . For example, the first end  2810  may be disposed on the first disk part  2311  of the first piezoelectric device  2310 . In detail, the first end  2810  may be disposed on one surface of the first disk part  2311 . Also, the first end  2810  may be disposed on the second piezoelectric device  2510  of the fourth driving unit  2500 . For example, the second end  2820  may be disposed on the second disk part  2511  of the second piezoelectric device  2510 . In detail, the first end  2810  may be disposed on one surface of the second disk part  2511 . 
     The second substrate  2800  may include a second end  2820 . The first end  2810  may be spaced apart from the first end  2810 . Also, the second end  2820  may be disposed in a region that does not overlap the first end  2810  in the optical axis direction. 
     The second end  2820  may be disposed on the first piezoelectric device  2310  of the third driving unit  2300 . For example, the second end  2820  may be disposed on the first disk part  2311  of the first piezoelectric device  2310 . In detail, the first end  2810  may be disposed on the other surface opposite to one surface of the first disk part  2311 . Also, the second end  2820  may be disposed on the second piezoelectric device  2510  of the fourth driving unit  2500 . For example, the second end  2820  may be disposed on the second disk part  2511  of the second piezoelectric device  2510 . In detail, the second end  2820  may be disposed on the other surface opposite to one surface of the second disk part  2511 . 
     That is, the second substrate  2800  may supply power to the first piezoelectric device  2310  and the second piezoelectric device  2510 . Accordingly, the third driving unit  2300  and the fourth driving unit  2500  may drive the first lens barrel  2200  and the second lens barrel  2400  by the applied power, respectively. 
     As described above, the second camera actuator  2000  according to the embodiment includes a third driving unit  2300  and a fourth driving unit  2500  including a piezoelectric device, and the first and second lens barrels  2200  and  2400  may be moved in the optical axis direction by the third and fourth driving units  2300  and  2500 . However, the embodiment is not limited thereto, and the third and fourth driving units  2300  and  2500  may include a voice coli motor (VCM) or a shape memory alloy. In this case, the third and fourth driving units  2300  and  2500  may move the first and second lens barrels  2200  and  2400  by using the electromagnetic force of the VCM or a physical change of the shape memory alloy. 
     The second camera actuator  2000  according to the embodiment may include an image sensor  2900 . The image sensor  2900  may collect light passing in the order of the first lens unit  2105 , the second lens unit  2205 , and the third lens unit  2405  and convert it into an image. The image sensor  2900  may be disposed to coincide with an optical axis of a lens of the lens units  105 ,  205 , and  405 . The optical axis of the image sensor  2900  and the optical axis of the lens may be aligned. 
       FIG.  21    is a perspective view of a mobile terminal to which a camera module according to an embodiment is applied. 
     Referring to  FIG.  21   , the mobile terminal  3  may include a camera module  10 , an autofocus device  31 , and a flash module  33  provided on the rear side. 
     The camera module  10  may include an image capturing function and an auto focus function. For example, the camera module  10  may include an auto-focus function using an image. 
     The camera module  10  processes an image frame of a still image or a moving image obtained by an image sensor in a shooting mode or a video call mode. The processed image frame may be displayed on a predetermined display unit and stored in a memory. A camera (not shown) may also be disposed on the front of the mobile terminal body. 
     For example, the camera module  10  may include a first camera module  10 A and a second camera module  10 B. In this case, at least one of the first camera module  10 A and the second camera module  10 B may include the aforementioned camera module, for example, the camera module  10  according to  FIGS.  1  to  20   . Accordingly, the camera module  10  may implement an OIS function together with a zoom function and an autofocus function. 
     The auto focus device  31  may include an auto focus function using a laser. The auto focus device  31  may be mainly used in a condition in which the auto focus function using the image of the camera module  10  is deteriorated, for example, in proximity of 10 m or less or in a dark environment. The autofocus device  31  may include a light emitting unit including a vertical cavity surface emitting laser (VCSEL) semiconductor device and a light receiving unit that converts light energy such as a photodiode into electrical energy. 
     The flash module  33  may include a light emitting device emitting light therein. The flash module  33  may be operated by a camera operation of a mobile terminal or by a user’s control. 
     Next,  FIG.  22    is a perspective view of the vehicle  5  to which the camera module according to the embodiment is applied. For example,  FIG.  22    is an external view of a vehicle including a vehicle driving assistance device to which the camera module  10  according to the embodiment is applied. 
     Referring to  FIG.  22   , the vehicle  5  according to the embodiment may include wheels  53 FL and  53 RL that rotate by a power source and a predetermined sensor. The sensor may be the camera sensor  51 , but is not limited thereto. 
     The camera  51  may be a camera sensor to which the camera module according to the embodiment, for example, the camera module  10  according to  FIGS.  1  to  20    is applied. 
     The vehicle  5  of the embodiment may acquire image information through a camera sensor  51  that captures a front image or a surrounding image, and it is possible to determine a lane non-identification situation using the image information, and generate a virtual lane when the lane is not identified. 
     For example, the camera sensor  51  may acquire a front image by photographing the front of the vehicle  5 , and a processor (not shown) may obtain image information by analyzing an object included in the front image. 
     For example, when an object such as a median, curb, or street tree corresponding to a lane, an adjacent vehicle, a driving obstacle, and an indirect road marking is captured in the image captured by the camera sensor  51 , the processor may detect such an object and include it in the image information. 
     In this case, the processor may further supplement the image information by acquiring distance information from the object detected through the camera sensor  51 . The image information may be information about an object photographed in an image. 
     The camera sensor  51  may include an image sensor and an image processing module. The camera sensor  51  may process a still image or a moving image obtained by an image sensor (eg, CMOS or CCD). The image processing module may process a still image or a moving image obtained through the image sensor, extract necessary information, and transmit the extracted information to the processor. 
     In this case, the camera sensor  51  may include a stereo camera to improve the measurement accuracy of the object and further secure information such as the distance between the vehicle  5  and the object, but is not limited thereto. 
     Features, structures, effects, etc. described in the above embodiments are included in at least one embodiment, and it is not necessarily limited to only one embodiment. Furthermore, features, structures, effects, etc. illustrated in each embodiment can be combined or modified for other embodiments by those of ordinary skill in the art to which the embodiments belong. Accordingly, the contents related to such combinations and variations should be interpreted as being included in the scope of the embodiments. 
     In the above, the embodiment has been mainly described, but this is only an example and does not limit the embodiment, and those of ordinary skill in the art to which the embodiment pertains will appreciate that various modifications and applications not illustrated above are possible without departing from the essential characteristics of the present embodiment. For example, each component specifically shown in the embodiment can be implemented by modification. And the differences related to these modifications and applications should be interpreted as being included in the scope of the embodiments set forth in the appended claims.