Patent Publication Number: US-9848126-B2

Title: Camera module

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 14/658,527 filed on Mar. 16, 2015 which claims the priorities and benefits of Korean Patent Application Nos. 10-2014-0043833 filed on Apr. 11, 2014, 10-2014-0066563 filed on May 30, 2014, 10-2014-0102588 filed on Aug. 8, 2014, and 10-2014-0139736 filed on Oct. 16, 2014, with the Korean Intellectual Property Office, the disclosures of which are incorporated herein by reference. 
    
    
     BACKGROUND 
     The present inventive concept relates to a camera module mounted in a portable terminal. 
     Camera modules mounted in portable terminals commonly have an auto-focusing function. In addition, such camera modules frequently have an optical image stabilization (OIS) function for mitigating resolution degradation due to hand-shake. 
     The camera module having the above function may have a structure in which a lens unit may move in an optical axis direction with respect to a housing of the camera module or in a direction perpendicular thereto. 
     However, in such a structure, the lens unit may easily collide with the housing of the camera module due to external impacts, and thus, a structure for reducing damage or noise caused by such external impacts is required. 
     RELATED ART DOCUMENT 
     KR No. 2011-0011192 A 
     SUMMARY 
     An aspect of the present inventive concept may provide a camera module having a structure resistant to external impacts. 
     According to an aspect of the present inventive concept, a camera module may have a structure for eliminating or reducing collisions between a lens unit and a housing. 
     According to another aspect of the present inventive concept, a camera module may have a structure enabling a reduction in collisions between a lens unit and a shield can. 
     According to still another aspect of the present inventive concept, a camera module may have a structure enabling a reduction in collisions between a lens unit and a housing or lens holder. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The above and other aspects, features and other advantages of the present inventive concept will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is an exploded perspective view of a camera module according to an exemplary embodiment in the present inventive concept; 
         FIG. 2  is a combined perspective view of the camera module of  FIG. 1 ; 
         FIG. 3  is a perspective view of the camera module of  FIG. 2  in a state in which a shield can is removed therefrom; 
         FIG. 4  is a cut perspective view of the camera module of  FIG. 2  taken along line A-A; 
         FIG. 5  is an enlarged cross-sectional view of portion B of  FIG. 4 , illustrating a modified state of a shock absorbing member due to external impacts; 
         FIG. 6  is an enlarged perspective view of portion C of  FIG. 4 ; 
         FIG. 7  is an enlarged cross-sectional view of portion C of  FIG. 4 , illustrating a modified state of a shock absorbing member due to external impacts; 
         FIGS. 8A and 8B  are cross-sectional views of shock absorbing members having other forms, respectively; 
         FIGS. 9A and 9B  are views of modified states of the shock absorbing members of  FIG. 8 , respectively; 
         FIG. 10  is a partially cut perspective view of a camera module according to another exemplary embodiment in the present inventive concept; and 
         FIG. 11  is a view of a modified state of a second shock absorbing member due to external impacts. 
     
    
    
     DETAILED DESCRIPTION 
     Exemplary embodiments of the present inventive concept will now be described in detail with reference to the accompanying drawings. 
     The inventive concept may, however, be exemplified in many different forms and should not be construed as being limited to the specific embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. 
     In the drawings, the shapes and dimensions of elements may be exaggerated for clarity, and the same reference numerals will be used throughout to designate the same or like elements. 
     As used herein, in the present inventive concept, it will be further understood that the terms “include” and/or “have” when used in the present inventive concept, specify the presence of elements, but do not preclude the presence or addition of one or more other elements, unless otherwise indicated. 
     Referring to  FIG. 1 , a camera module according to an exemplary embodiment in the present inventive concept will be described. 
     A camera module  10  may include a housing unit  100 , an actuator unit  200 , and a lens unit  300 . In addition, the camera module  10  may further include one or more shock absorbing members  500 . 
     The housing unit  100  may include a housing  110  and a shield can  120 . 
     The housing  110  may be formed of an easily moldable material. For example, the housing  110  may be manufactured of a plastic material. One or more actuator units  200  may be mounted in the housing  110 . For example, a portion of a first actuator  210  may be mounted on a first side surface of the housing  110 , and portions of a second actuator  220  may be mounted on second through fourth side surfaces of the housing  110 , respectively. The housing  110  may be configured to accommodate the lens unit  300  therein. For example, an accommodation space for entirely or partially accommodating the lens unit  300  therein may be formed inside the housing  110 . The housing  110  may have six surfaces including openings formed therein, respectively. For example, the housing  110  may have a bottom surface in which a rectangular opening for an image sensor is formed, and may have a top surface in which a square opening for mounting the lens unit  300  therein is formed. In addition, the housing  110  may have the first side surface in which an opening for inserting a first coil  212  of the first actuator  210  thereto is formed, and may have the second through fourth side surfaces in which openings for inserting second coils  222  of the second actuator  220  thereto are formed, respectively. 
     The shield can  120  may be configured to cover a portion of the housing  110 . For example, the shield can  120  may be configured to cover the top surface of the housing  110  and the four side surfaces of the housing  110 . However, a shape of the shield can  120  is not limited to a shape to cover all of the above-described portions. For example, the shield can  120  may be configured to only cover the four side surfaces of the housing  110 . Alternatively, the shield can  120  may be configured to partially cover the top surface of the housing  110  and the four side surfaces of the housing  110 . 
     The actuator unit  200  may be configured to move the lens unit  300  in one or more directions. For example, the actuator unit  200  may be configured to move the lens unit  300  in a direction of an optical axis (Z axis direction with reference to  FIG. 1 ) and directions (X axis direction and Y axis direction with reference to  FIG. 1 ) perpendicular with respect to the optical axis. 
     The actuator unit  200  may include a plurality of actuator units. As an example, the actuator unit  200  may include the first actuator  210  configured to move the lens unit  300  in the Z axis direction (with reference to  FIG. 1 ) and the second actuator  220  configured to move the lens unit  300  in the X axis direction and the Y axis direction (with reference to  FIG. 1 ). 
     The first actuator  210  may be mounted in the housing  110  and a first frame  310  of the lens unit  300 . For example, a portion of the first actuator  210  may be mounted on the first side surface of the housing  110  and a remaining portion of the first actuator  210  may be mounted on a first side surface of the first frame  310 . The first actuator  210  may include an element for moving the lens unit  300  in the direction of the optical axis. As an example, the first actuator  210  may include the first coil  212 , a first permanent magnet  214 , a first substrate  216 , and a first sensor  218 . The first coil  212  and the first sensor  218  may be formed on the first substrate  216 . The first substrate  216  may be mounted on the first side surface of the housing  110 , and the first permanent magnet  214  may be mounted on the first side surface of the first frame  310  facing the first substrate  216 . 
     The first actuator  210  configured as above may allow relative movement of the first frame  310  and a lens barrel  340  with respect to the housing  110  by changing intensity and a direction of magnetic force generated between the first coil  212  and the first permanent magnet  214 . In addition, the first actuator  210  configured as above may detect a position of the first frame  310  based on a change in a magnetic flux detected by the first sensor  218 . 
     The second actuator  220  may be mounted in the housing  110  and a third frame  330  of the lens unit  300 . For example, portions of the second actuator  220  may be mounted on the second through fourth side surfaces of the housing  110 , respectively, and a remaining portion of the second actuator  220  may be mounted on second through fourth side surfaces of the third frame  330 . The second actuator  220  may include an element for moving the lens unit  300  in the direction perpendicular with respect to the optical axis. As an example, the second actuator  220  may include a plurality of second coils  222 , a plurality of second permanent magnets  224 , a second substrate  226 , and one or more second sensors  228 . The plurality of second coils  222  and the one or more second sensors  228  may be formed on the second substrate  226 . The second substrate  226  may be generally formed to have the shape of   and may be mounted to surround the second through fourth side surfaces of the housing  110 . The plurality of second permanent magnets  224  may be mounted on the second through fourth side surfaces of the third frame  330  to face three surfaces of the second substrate  226 , respectively. 
     The second actuator  220  configured as above may allow relative movement of the second frame  320  and the third frame  330  with respect to the first frame  310  by changing intensity and a direction of magnetic force generated between the plurality of second coils  222  and the plurality of second permanent magnets  224 . For reference, the lens barrel  340  may move in the same direction as that of the second frame  320  and the third frame  330  by movement of the second frame  320  and the third frame  330 . The second actuator  220  configured as above may detect positions of the second frame  320  and the third frame  330  based on a change in a magnetic flux detected by the second sensor  228 . 
     The lens unit  300  may be mounted in the housing unit  100 . For example, the lens unit  300  may be accommodated in an accommodation space formed by the housing  110  and the shield can  120  in a manner in which the lens unit  300  may move in at least three axis directions. 
     The lens unit  300  may be configured of a plurality of frames. For example, the lens unit  300  may include the first frame  310 , the second frame  320 , and the third frame  330 . 
     The first frame  310  may be configured to move with respect to the housing  110 . As an example, the first frame  310  may move in a height direction (Z axis direction with reference to  FIG. 1 ) of the housing  110  by the first actuator  210 . A plurality of guide grooves  312  and  314  may be formed in the first frame  310 . As an example, the first guide grooves  312  elongatedly formed to extend in the direction of the optical axis (Z axis direction with reference to  FIG. 1 ) may be formed in the first side surface of the first frame  310 , and the second guide grooves  314  elongatedly formed to extend in a direction (Y axis direction with reference to  FIG. 1 ) perpendicular with respect to the optical axis may be formed in four corners of an inner bottom surface of the first frame  310 , respectively. The first frame  310  may be manufactured to have at least three side surfaces including openings formed therein, respectively. For example, the second through fourth side surfaces of the first frame  310  may include respective openings such that the second permanent magnets  224  of the third frame  330  exposed through the openings may face the second coils  222  of the housing  110 , respectively. 
     The second frame  320  may be mounted in the first frame  310 . For example, the second frame  320  may be mounted in an interior of the first frame  310 . The second frame  320  may be configured to move in the direction perpendicular with respect to the optical axis, with respect to the first frame  310 . For example, the second frame  320  may move in the direction (Y axis direction with reference to  FIG. 1 ) perpendicular with respect to the optical axis along the second guide grooves  314  of the first frame  310 . A plurality of third guide grooves  322  may be formed in the second frame  320 . For example, four third guide grooves  322  elongatedly formed to extend in a direction (X axis direction with reference to  FIG. 1 ) perpendicular with respect to the optical axis may be formed in corners of the second frame  320 , respectively. 
     The third frame  330  may be mounted in the second frame  320 . For example, the third frame  330  may be mounted on a top surface of the second frame  320 . The third frame  330  may be configured to move in the direction perpendicular with respect to the optical axis, with respect to the second frame  320 . For example, the third frame  330  may move in the direction (X axis direction with reference to  FIG. 1 ) perpendicular with respect to the optical axis along the third guide grooves  322  of the second frame  320 . The plurality of second permanent magnets  224  may be mounted in the third frame  330 . For example, three third permanent magnets  224  may be mounted in the second through fourth side surfaces of the third frame  330 , respectively. 
     The lens unit  300  may include the lens barrel  340 . For example, the lens unit  300  may include the lens barrel  340  including one or more lenses. The lens barrel  340  may be mounted in the third frame  330 . For example, the lens barrel  340  may be inserted into the third frame  330  to move integrally with the third frame  330 . The lens barrel  340  may be configured to move in the direction of the optical axis and the direction perpendicular with respect to the optical axis. For example, the lens barrel  340  may move in the direction of the optical axis by the first actuator  210 , and may move in the direction perpendicular with respect to the optical axis by the second actuator  220 . 
     The lens unit  300  may further include a cover member  350 , a ball stopper  360 , and a magnetic body  370 . 
     The cover member  350  may be configured to prevent the second frame  320  and the third frame  330  from escaping from the interior of the first frame  310 . For example, the cover member  350  may be combined with the first frame  310  to suppress escaping of the second frame  320  and the third frame  330  upwardly of the first frame  310 . 
     The ball stopper  360  may be mounted in the first frame  310 . For example, the ball stopper  360  may be disposed to obscure the first guide grooves  312  of the first frame  310  to suppress escaping of first ball members  410  mounted in the first guide grooves  312  therefrom. 
     The magnetic body  370  may be mounted in the first frame  310 . For example, the magnetic body  370  may be mounted in at least one of the second through fourth side surfaces of the first frame  310  to generate magnetic attractive force between the second coil  222  and the second permanent magnet  224  of the second actuator  220 . The magnetic body  370  configured as above may fix positions of the second frame  320  and the third frame  330  with respect to the first frame  310  in an inactive state of the actuator unit  200 . For example, the lens unit  300  may be maintained at a predetermined position inside the housing  110  by magnetic attractive force between the magnetic body  370  and the second coil  222 . 
     The ball member  400  may be configured to smoothly move the lens unit  300 . For example, the ball member  400  may be configured to smoothly move the lens unit  300  in the direction of the optical axis and the direction perpendicular with respect to the optical axis. The ball member  400  may be divided into first ball members  410 , second ball members  420 , and third ball members  430  based on a disposition position. As an example, the first ball members  410  may be disposed in each of the first guide grooves  312  of the first frame  310  to smoothly move the first frame  310  in the direction of the optical axis. As another example, the second ball member  420  may be disposed in each of the second guide grooves  314  of the first frame  310  to smoothly move the second frame  320  in a direction perpendicular with respect to the optical axis. As still another example, the third ball member  430  may be disposed in each of the third guide grooves  322  of the second frame  320  to smoothly move the third frame  330  in another direction perpendicular with respect to the optical axis. For reference, although not illustrated in  FIG. 1 , a lubricant for reducing friction and noise may be filled in all portions of the camera module  10  in which the ball member  400  is disposed. For example, a viscous fluid may be injected into each of the guide grooves  312 ,  314 , and  322 . Such a viscous fluid may use grease having excellent viscosity properties and lubrication properties. 
     The shock absorbing member  500  may be configured to reduce noise caused by movement of the lens unit  300 . For example, the shock absorbing member  500  may be configured to reduce collision noise caused by moving the lens unit  300  in the direction of the optical axis and the direction perpendicular with respect to the optical axis due to external impacts. As an example, the shock absorbing member  500  may be formed in the cover member  350  to reduce collision noise generated between the lens unit  300  and the housing unit  100 . 
     The shock absorbing member  500  may be manufactured of a material having a relatively high Poisson ratio. For example, the shock absorbing member  500  may be manufactured of a material having a Poisson ratio higher than 0.4. As an example, the shock absorbing member  500  may be formed of a rubber material. As another example, the shock absorbing member  500  may be formed of a liquified material capable of being gelled at a room temperature. That is, the shock absorbing member  500  may be formed of a sol state material, a gel state material, or the like. 
     Referring to  FIG. 2 , a combined form of the camera module  10  will be described. 
     The camera module  10  may have both an auto-focusing function and an optical image stabilization (OIS) function. For example, the lens barrel  340  may move in the direction of the optical axis and the direction perpendicular with respect to the optical axis inside the housing unit  100 . Thus, the miniaturization and the slimming of the camera module  10  according to the present exemplary embodiment may be relatively easily achieved. 
     Referring to  FIG. 3 , the camera module  10  in a state in which the shied can  120  is removed therefrom will be described. 
     The camera module  10  may include one or more shock absorbing members  500 . As an example, the one or more shock absorbing members  500  may be formed in the cover member  350  of the lens unit  300  as illustrated in  FIG. 3 . The shock absorbing members  500  formed as above may reduce noise due to vibrations of the lens barrel  340  caused by rapid movement of the lens barrel  340  or external impacts. As an example, the shock absorbing members  500  may reduce impacts and collision noise generated when the cover member  350  of the first frame  310  and the shield can  120  collide, due to vibrations of the lens barrel  340 . 
     Referring to  FIG. 4 , a cross-sectional structure of the camera module  10  will be described. 
     The camera module  10  may have the cross-sectional structure illustrated in  FIG. 4 . For example, the first frame  310  may be in point contact with the housing  110  by the first ball members  410 , and the second frame  320  may be in point contact with the first frame  310  by the second ball members  420 . 
     The camera module  10  configured as above may enable soft movement of the lens unit  300  due to relatively low friction resistance between the housing  110  and the first frame  310  and between the first frame  310  and the second frame  320 . 
     In addition, the shock absorbing members  500  may be formed between the lens unit  300  and the housing unit  100 , thereby reducing collisions occurring and collision noise generated between the lens unit  300  and the housing unit  100  due to external impacts. 
     Referring to  FIG. 5 , a scheme of reducing collision noise by using the shock absorbing members  500  will be described. 
     The shock absorbing members  500  may be configured to reduce collision energy and collision noise generated by rapid upward movement (direction with reference to  FIG. 4 ) of the lens unit  300 . For example, the shock absorbing members  500  may be disposed between the cover member  350 , that is, a portion of the lens unit  300 , and the shield can  120 , that is, a portion of the housing unit  100 , to reduce impacts and collision noise due to collisions between the cover member  350  and the shield can  120 . 
     That is, the shock absorbing members  500  may be modified in a manner in which an area of the shock absorbing member  500  to come into contact with the cover member  350  is increased or a length of the shock absorbing member  500  is reduced when the cover member  350  and the shield can  120  collide, whereby contact time t between the cover member  350  and the shield can  120  may be increased. Such an increase in contact time t may reduce intensity of force F with respect to impact energy (W=F*t) having a predetermined magnitude, whereby collision noise as well as force F actually applied to the cover member  350  or the shield can  120  may be reduced. 
     Referring to  FIG. 6 , portion C of the camera module  10  will be described. 
     The shock absorbing member  500  may be formed in a lower portion of the lens unit  300 . For example, one or more shock absorbing members  500  may be formed between the first frame  310  of the lens unit  300  and the housing  110  of the housing unit  100 . 
     The shock absorbing members  500  disposed as above may reduce collision energy with the housing unit  100  due to rapid downward movement (direction with reference to  FIG. 6 ) of the lens unit  300  and may reduce collision noise generated at the time of collisions. 
     Referring to  FIG. 7 , a scheme of reducing collision noise by using the shock absorbing members  500  will be described. 
     The shock absorbing members  500  may be configured to reduce collision energy and collision noise generated by rapid downward movement (direction with reference to  FIG. 4 ) of the lens unit  300 . For example, the shock absorbing members  500  may be disposed between the first frame  310 , that is, a portion of the lens unit  300 , and the housing  110 , that is, a portion of the housing unit  100 , to reduce impacts and collision noise generated due to collisions between the first frame  310  and the housing  110 . 
     That is, the shock absorbing members  500  may be modified in a manner in which an area of the shock absorbing member  500  to come into contact with the first frame  310  is increased or a length of the shock absorbing member  500  is reduced when the first frame  310  and the housing  110  collide, whereby contact time t between the first frame  310  and the housing  110  may be increased. Such an increase in contact time t may reduce intensity of force F with respect to impact energy (W=F*t) having a predetermined magnitude, whereby collision noise as well as force F actually applied to the first frame  310  or the housing  110  may be reduced. 
     Referring to  FIGS. 8A and 8B , other forms of shock absorbing members will be described. 
     The shock absorbing members  500  may be modified as illustrated in  FIGS. 8A and 8B . For example, the shock absorbing member  500  may have a form easily elastically modifiable due to impacts. 
     The shock absorbing member  500  may be configured of a fixing unit  502  fixed to the lens unit  300  and a modification unit  504  to be modified by impacts. The fixing unit  502  may have a protruding shape insertable into the lens unit  300 , and the modification unit  504  may be bent or compressed due to impacts. 
     Referring to  FIGS. 9A and 9B , a modified shape of the shock absorbing member  500  due to impacts will be described. 
     The shock absorbing member  500  of  FIG. 8A  may be easily compressed due to impacts. For example, the shock absorbing member  500  may be compressed due to collisions between the cover member  350  and the shield can  120  as illustrated in  FIG. 9A , thereby reducing collision noise. 
     The shock absorbing member  500  of  FIG. 8B  may be easily bent due to impacts. For example, the shock absorbing member  500  may be bent due to collisions between the cover member  350  and the shield can  120  as illustrated in  FIG. 9B , thereby reducing collision noise. 
     Referring to  FIG. 10 , a camera module according to another exemplary embodiment will be described. 
     A camera module  10  according to another exemplary embodiment may be different from that according to the exemplary embodiment in terms of a disposition form of shock absorbing members  500 . For example, the shock absorbing member  500  may include first shock absorbing members  510  for reducing collisions and collision noise generated in a direction of an optical axis and second shock absorbing members  520  for reducing collision occurring and collision noise generated in a direction perpendicular with respect to the optical axis. 
     The first shock absorbing members  510  may be formed in a plane (X-Y plane with reference to  FIG. 10 ) perpendicular with respect to the optical axis in a lens unit  300 . For example, the first shock absorbing members  510  may be formed in upper and lower surfaces of the lens unit  300 . The first shock absorbing member  510  formed as above may reduce collisions with and collision noise generated with respect to a housing unit  100  caused by rapid movement of the lens unit  300  in the direction of the optical axis due to external impacts. 
     The second shock absorbing members  520  may be formed in planes (X-Z plane and Y-Z plane with reference to  FIG. 10 ) parallel with respect to the optical axis in the lens unit  300 . For example, the second shock absorbing members  520  may be formed in four side surfaces of the lens unit  300 . The second shock absorbing members  520  formed as above may reduce collisions with and collision noise generated with respect to the housing unit  100  caused by rapid movement of the lens unit  300  in the direction perpendicular with respect to the optical axis due to external impacts. 
     Referring to  FIG. 11 , a scheme of reducing collision noise by using the second shock absorbing members  520  will be described. 
     The second shock absorbing members  520  may be configured to reduce collision energy and collision noise generated by rapid horizontal movement (X-Y direction with reference to  FIG. 10 ) of the lens unit  300 . For example, the second shock absorbing members  520  may be disposed between a first frame  310  a third frame  330  to reduce collision noise due to collisions between the first frame  310  and the third frame  330 . 
     That is, the second shock absorbing member  520  may be modified in a manner in which an area of the second shock absorbing member  520  to come into contact with the third frame  330  is increased and a length of the second shock absorbing members  520  is reduced when the first frame  310  and the third frame  330  collide, whereby collision noise due to collisions between the first frame  310  and the third frame  330  may be reduced. 
     As set forth above, according to exemplary embodiments of the present inventive concept, damage incurred to and noise generated in a camera module due to external impacts may be reduced. 
     While exemplary embodiments have been illustrated and described above, it will be apparent to those skilled in the art that modifications and variations could be made without departing from the scope of the invention as defined by the appended claims.