Patent Publication Number: US-2016246159-A1

Title: Camera module

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 USC 119(a) of Korean Patent Application No. 10-2015-0026701 filed on Feb. 25, 2015, in the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference for all purposes. 
     BACKGROUND 
     1. Field 
     This application relates to a camera module having a rapid focusing function. 
     2. Description of Related Art 
     A high-resolution camera apparatus includes a plurality of lenses and an image sensor. Such a camera apparatus includes a moving means moving a lens barrel in an optical axis direction to obtain a clear image. 
     However, such a structure may be a hindrance in miniaturizing camera apparatuses, since the lens barrel, a member having significant mass, is moved to adjust a focal length, which leads to relatively high current consumption, and a structure of the moving mechanism thereof is complicated. 
     SUMMARY 
     This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter. 
     In one general aspect, a camera module includes a first housing having at least one fixed lens mounted therein; a second housing coupled to the first housing and having a movable lens mounted therein; and an actuator configured to move the second housing relative to the first housing. 
     The camera module may further include an elastic member connecting the first housing and the second housing and supporting the second housing to enable the second housing to move relative to the first housing. 
     The actuator may include a coil member disposed on the first housing; and a magnet member disposed on the second housing. 
     The second housing may be mounted in the first housing. 
     The movable lens may include one or more protrusions extending perpendicularly to an optical axis of the movable lens. 
     A groove accommodating a portion of the movable lens may be formed in the second housing. 
     The second housing may have an opening configured to accommodate at least a portion of a fixed lens of the at least one fixed lens as the actuator moves the second housing relative to the first housing. 
     The camera module may further include a shield can accommodating the first housing and the second housing. 
     The camera module may further include a third housing coupled to the first housing and having at least one fixed lens mounted therein. 
     The second housing may be disposed between the first housing and the third housing. 
     The camera module may further include a sensor configured to sense a position of the second housing. 
     In another general aspect, a camera module includes a first housing having a fixed lens mounted therein; a second housing coupled to the first housing and having a movable lens mounted therein; and an actuator configured to move the movable lens relative to the fixed lens. 
     The camera module may further include an elastic member disposed in the second housing and supporting the movable lens to enable the movable lens to move relative to the second housing. 
     The actuator may include a coil member disposed on the second housing; and a magnet member disposed on the movable lens. 
     The camera module may further include a shield can accommodating the first housing and the second housing. 
     In another general aspect, a camera module includes a first housing having a fixed lens mounted therein; a second housing having a movable lens mounted therein; and an actuator configured to move the movable lens relative to the fixed lens; wherein the second housing is disposed between the first housing and an image plane of the camera module. 
     The movable lens may be a closest lens to the image plane of the camera module. 
     The camera module may further include an elastic member connecting the movable lens to the second housing and configured to enable the movable lens to move relative to the second housing. 
     The actuator may include a coil member disposed on the second housing; and a magnet member disposed on the movable lens. 
     The fixed lens may be one of a plurality of fixed lenses mounted in the first housing; and the movable lens may be the only lens mounted in the second housing. 
     Other features and aspects will be apparent from the following detailed description, the drawings, and the claims. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an exploded perspective view of an example of a camera module. 
         FIG. 2  is an assembled perspective view of the camera module illustrated in  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the camera module taken along the line III-III in  FIG. 2 . 
         FIGS. 4 and 5  are cross-sectional views illustrating operating states of the camera module illustrated in  FIG. 1 . 
         FIGS. 6 and 7  are plan views illustrating a method of aligning an optical axis of a movable lens illustrated in  FIG. 1 . 
         FIG. 8  is a cross-sectional view of another example of a camera module taken along the line III-III in  FIG. 2 . 
         FIG. 9  is a cross-sectional view of another example of a camera module taken along the line III-III in  FIG. 2 . 
         FIG. 10  is a cross-sectional view of another example of a camera module taken along line the line III-III in  FIG. 2 . 
       Throughout the drawings and the detailed description, the same reference numerals refer to the same elements. The drawings may not be to scale, and the relative size, proportions, and depiction of elements in the drawings may be exaggerated for clarity, illustration, and convenience. 
     
    
    
     DETAILED DESCRIPTION 
     The following detailed description is provided to assist the reader in gaining a comprehensive understanding of the methods, apparatuses, and/or systems described herein. However, various changes, modifications, and equivalents of the methods, apparatuses, and/or systems described herein will be apparent to one of ordinary skill in the art. The sequences of operations described herein are merely examples, and are not limited to those set forth herein, but may be changed as will be apparent to one of ordinary skill in the art, with the exception of operations necessarily occurring in a certain order. Also, descriptions of functions and constructions that are well known to one of ordinary skill in the art may be omitted for increased clarity and conciseness. 
     The features described herein may embodied in different forms, and are not to be construed as being limited to the examples described herein. Rather, the examples described herein have been provided so that this disclosure will be thorough and complete, and will convey the full scope of the disclosure to one of ordinary skill in the art. 
     A camera module according to this application performs a rapid focusing function. For example, the camera module may only move one lens in an optical axis direction. As another example, the camera module may only move the smallest lens or the lightest lens in the optical axis direction. 
     Since the camera module as described above only moves one lens or the smallest or lightest lens, the amount of current necessary to drive the lens is reduced and a driving time needed to drive the lens is also reduced. 
       FIG. 1  is an exploded perspective view of an example of a camera module. 
     A camera module  100  includes a first housing  110 , a second housing  120 , a fixed lens  130 , a movable lens  140 , and an actuator  160 . Further, the camera module  100  includes an elastic member  150  connecting the first housing  110  and the second housing  120 . In addition, the camera module  100  includes a shield can  180  to block harmful electromagnetic waves. 
     The first housing  110  accommodates a plurality of components therein. For example, the first housing  110  accommodates one or more fixed lenses  130  therein. Further, the first housing  110  accommodates the second housing  120  therein. As another example, the first housing  110  accommodates a portion of the actuator  160 . 
     The second housing  120  accommodates one or more movable lenses  140 . In this example, the second housing  120  accommodates one movable lens  140 . However, the number of movable lenses  140  accommodated in the second housing  120  is limited to one. For example, the second housing  120  may accommodate two or more movable lenses  140 . The second housing  120  may partially accommodate the fixed lens  130 . For example, one surface of the second housing  120  may have an opening to accommodate a portion of the fixed lens  130  as the second housing  120  is moved in the optical axis direction. 
     The second housing  120  is coupled to portions of the movable lens  140 . In this example, grooves  122  into which the portions of the movable lens  140  are inserted are formed in the surface of the second housing  120 . 
     The fixed lens  130  is mounted in the first housing  110 . For example, one or more fixed lenses  130  are sequentially disposed in a height direction (a vertical direction in  FIG. 1 ) of the first housing  110 . The fixed lens  130  is fixed to the first housing  110 . For example, one or more fixed lenses  130  may be firmly fixed to the first housing  110  by an adhesive or fastener. 
     The movable lens  140  is mounted in the second housing  120 . In this example, one movable lens  140  is mounted on one surface of the second housing  120 . The movable lens  140  is disposed to have the same optical axis as the fixed lens  130 . For example, the optical axis of the movable lens  140  and an optical axis of the fixed lens  130  coincide with each other. This condition is advantageous in improving a resolution of the camera module  100 . 
     The movable lens  140  is moved to adjust a distance between the movable lens  140  and the fixed lens  130 . For example, the movable lens  140  is moved in the optical axis direction to adjust the distance between the movable lens and the fixed lens  130 . For example, the movable lens  140  may be moved in a direction away from the fixed lens  130 . Further, the movable lens  140  may be moved in a direction toward the fixed lens  130 . The movement of the movable lens  140  is performed by the actuator  160 . 
     The movable lens  140  is coupled to the second housing  120 . In this example, the movable lens  140  includes one or more protrusions  142  inserted into the grooves  122  of the second housing  120 . 
     The elastic member  150  connects the first housing  110  and the second housing  120 . In this example, an edge portion of the elastic member  150  is connected to the first housing  110 , and a central portion of the elastic member  150  is connected to the second housing  120 . 
     The elastic member  150  is made of a material that may be easily deformed. Accordingly, the second housing  120  may be moved relative to the first housing  110 . For example, as the elastic member  150  is deformed, the second housing  120  is moved out of the first housing  110  (an upward direction thereof in  FIG. 1 ). As another example, as the elastic member  150  is deformed, the second housing  120  is moved into the first housing  110  (a downward direction thereof in  FIG. 1 ). 
     The elastic member  150  may include a portion having a plate spring form. For example, a portion of the elastic member  150  connecting the first housing  110  and the second housing  120  may have the plate spring form. 
     The actuator  160  adjusts a position of the movable lens  140 . In this example, the actuator  160  moves the second housing  120  in the optical axis direction to change the position of the movable lens  140 . 
     The actuator  160  includes a coil member  162  and a magnet member  164 . The actuator  160  moves the second housing  120  or the movable lens  140  by an electromagnetic force generated between the coil member  162  and the magnet member  164 . 
     The coil member  162  may be disposed on the first housing  110 . As another example, the coil member  162  may be disposed on an outer surface of the first housing  110 . 
     The magnet member  164  may be disposed on the second housing  120 . As another example, the magnet member  164  may be disposed on a portion of the second housing  120  facing the coil member  162 . 
     The actuator  160  changes a direction of electromagnetic force generated between the coil member  162  and the magnet member  164  according to electrical signals applied to the coil member  162  to adjust a position of the second housing  120  or the position of the movable lens  140 . As an example, the actuator  160  may move the movable lens  140  in the optical axis direction. As another example, the actuator  160  may tilt the movable lens  140  so that an optical axis of the movable lens  140  coincides with an optical axis of the camera module. 
     The shield can  180  protects the first housing  110  and the second housing  120 . As an example, the shield can  180  protects components mounted in the first and second housings  110  and  120  from harmful electromagnetic waves. To this end, the shield can  180  may be formed of a metal. However, a material forming the shield can  180  is not limited to metal. As an example, the shield can  180  may be formed of a resin mixture including a metal powder or other metallic components. 
     The shield can  180  allows an effective light to be incident therethrough. For example, a hole  182  having substantially the same diameter as diameters of the lenses  130  and  140  is formed in one surface of the shield can  180 . The hole  182  is formed in a position coinciding with the optical axes of the lenses  130  and  140  in one surface of the shield can  180 . 
       FIG. 2  is an assembled perspective view of the camera module illustrated in  FIG. 1 . 
     The camera module  100  is assembled to form a single part. As an example, the camera module  100  is assembled so that the first housing  110  accommodates all other components therein. As another example, the camera module  100  may be assembled so that a closed space formed by the first housing  110  and the shield can  180  accommodate all other components. 
     The camera module  100  may be easily mounted in a small portable electronic device. 
       FIG. 3  is a cross-sectional view of the camera module taken along the line III-III in  FIG. 2 . 
     The camera module  100  is configured so that the fixed lens  130  and the movable lens  140  are sequentially disposed in the first housing  110 . In this example, a plurality of fixed lenses  130  ( 132 ,  134 , and  136 ) are sequentially disposed in a lower portion of the first housing  110 , and the movable lens  140  is disposed in an upper portion of the first housing  110 . 
     The second housing  120  is disposed in the first housing  110 . In this example, the second housing  120  is disposed in the first housing  110  in a state in which the second housing  120  accommodates the movable lens  140 . 
     The second housing  120  may be moved in the optical axis direction in the first housing  110 . As an example, the second housing  120  may be moved downwardly or upwardly in the first housing  110  by the actuator  160 . 
     The position of the second housing  120  is by a sensor  166 . For example, the sensor  166  may sense magnetic force generated by the magnet member  164  formed on the second housing  120  to sense the position of the second housing  120 . As another example, the sensor  166  may sense the position of the second housing  120  by sensing a magnitude of magnetic flux generated between the coil member  162  and the magnet member  164 . For reference, a height L of the coil member  162  of the actuator  160  may advantageously be the same as a driving range of the second housing  120  or larger than the driving range of the second housing  120 . 
       FIGS. 4 and 5  are cross-sectional views illustrating operating states of the camera module illustrated in  FIG. 1 . 
     The camera module  100  performs an auto-focusing function. As an example, the camera module  100  moves the movable lens  140  in a direction of a subject to enable a clear image of a distant subject to be captured (see  FIG. 4 ). As another example, the camera module  100  moves the movable lens  140  in a direction of an image plane (a direction of an image sensor) to enable a clear image of a near subject to be captured (see  FIG. 5 ). As another example, the camera module  100  freely moves the position of the movable lens  140  to enable a clear image of the subject to be captured regardless of the distance of the subject. 
     Since the camera module  100  only moves a few movable lenses  140  in the subject direction or the image plane direction, it may rapidly perform a focusing function. Further, in the camera module  100  in this example, since the actuator  160  only moves a few movable lenses  140  (one movable lens  140  in this example, it may significantly reduce an amount of current consumed in performing the focusing function. 
       FIGS. 6 and 7  are plan views illustrating a method of aligning an optical axis of the movable lens  140 . 
     The camera module  100  in this example enables an optical axis of the movable lens  140  to be aligned. For example, a position of the movable lens  140  in the second housing  120  may be adjusted. As an example, the movable lens  140  may be moved in a vertical direction of the optical axis and other directions in a length direction of the grooves  122  in a state in which the movable lens  140  is mounted in the second housing  120 . To this end, the grooves  122  of the second housing  120  are formed to be larger than the protrusions  142  of the movable lens  140 . 
     Next, a method of aligning an optical axis of the movable lens  140  will be described. 
     A method of aligning an optical axis of the movable lens  140  in this example is performed in the order of 1) mounting the movable lens  140 , 2) aligning an optical axis of the movable lens  140 , and 3) fixing the movable lens  140 . 
     1) Mounting Movable Lens  140   
     The movable lens  140  is mounted in the second housing  120 . As an example, the movable lens  140  is mounted in the second housing  120  by inserting the protrusions  142  into the grooves  122 . 
     2) Aligning Optical Axis of Movable Lens  140   
     An optical axis C 2  of the movable lens  140  is aligned with an optical axis C 1  of the fixed lens  130 . As an example, in a case in which the optical axis C 2  of the movable lens  140  is not aligned with the optical axis C 1  of the fixed lens  130  in a state in which the movable lens  140  is mounted in the second housing  120  (see  FIG. 6 ), the optical axis C 2  of the movable lens  140  is aligned with the optical axis C 1  of the fixed lens  130  by moving the movable lens  140  in a calibration direction (see  FIG. 7 ). 
     A series of processes of adjusting a tilting angle of the movable lens  140  may be further performed. 
     3) Fixing Movable Lens  140   
     The movable lens  140  and the second housing  120  are fixed together. As an example, the movable lens  140  is firmly fixed to the second housing  120  by applying an adhesive  190  in the grooves  122  of the second housing  120 . 
     Next, another example of a method of aligning an optical axis of the movable lens  140  will be described. A method of aligning an optical axis of the movable lens  140  in this example is performed in the order of 1) mounting the movable lens  140 , 2) temporarily fixing the movable lens  140 , 3) aligning an optical axis of the movable lens  140 , and 4) fixing the movable lens  140 . 
     1) Mounting Movable Lens  140   
     The movable lens  140  is mounted in the second housing  120 . As an example, the movable lens  140  is mounted in the second housing  120  by inserting the protrusions  142  into the grooves  122 . 
     2) Temporarily Fixing Movable Lens  140   
     The position of the movable lens  140  is temporarily fixed. As an example, the position of the movable lens  140  in the second housing  120  is temporarily fixed by applying an adhesive to the grooves  122  of the second housing  120 . The adhesive used here may be a type of adhesive that can be firmly cured by an additional curing process. As an example, a thermosetting or photo-setting adhesive may be used. 
     3) Aligning Optical Axis of Movable Lens  140   
     An optical axis C 2  of the movable lens  140  is aligned with an optical axis C 1  of the fixed lens  130 . As an example, in a case in which the optical axis C 2  of the movable lens  140  is not aligned with the optical axis C 1  of the fixed lens  130  in a state in which the movable lens  140  is mounted in the second housing  120  (see  FIG. 6 ), the optical axis C 2  of the movable lens  140  is aligned with the optical axis C 1  of the fixed lens  130  by moving the movable lens  140  in a calibration direction (see  FIG. 7 ). 
     4) Fixing Movable Lens  140   
     The movable lens  140  and the second housing  120  are firmly fixed together. As an example, the adhesive  190  applied to the groove  122  of the second housing  120  is cured. 
     Next, other examples of a camera module will be described. For reference, in the following description, the same components as those of the example of the camera module described above will be denoted by the same reference numerals and detailed descriptions thereof will be omitted. 
       FIG. 8  is a cross-sectional view of another example of a camera module taken along the line III-III in  FIG. 2 . 
     The camera module  100  in this example is distinguishable from the camera module described above by an arrangement of the second housing  120 . In this example, the second housing  120  is disposed in the upper portion of the first housing  110  so that the first housing  110  and the second housing  120  are disposed in series in the optical axis direction. This arrangement is advantageous for the camera module  100  including a plurality of lenses. 
     The camera module  100  in this example is distinguishable from the camera module described above by the coupling of the elastic member  150 . For example, the elastic member  150  connects the second housing  120  and the movable lens  140 . More specifically, the elastic member  150  connects the second housing  120  and the movable lens  140  so that the movable lens  140  may be moved relative to the second housing  120 . 
     The camera module  100  in this example is distinguishable from the camera module described above by an arrangement of the actuator  160 . In this example, the coil member  162  of the actuator  160  is disposed on the second housing  120 , and the magnet member  164  of the actuator  160  is disposed on the movable lens  140 . 
       FIG. 9  is a cross-sectional view of another example of a camera module taken along the line III-III in  FIG. 2 . 
     The camera module  100  in this example is distinguishable from the camera modules described above by an arrangement of the second housing  120 . In this example, the second housing  120  is disposed in the lower portion of the first housing  110  to accommodate a movable lens  140  that is a closest lens to an image side of the camera module  100 . This arrangement is advantageous in a case in which sufficient space is provided in an image-side portion (e.g., a portion between an image-side lens and an image sensor) of the camera module  100 . Alternatively, this arrangement is advantageous in a case in which a focusing function is effective due to the lens disposed on the image side. 
       FIG. 10  is a cross-sectional view of another example of a camera module taken along the line III-III in  FIG. 2 . 
     The camera module  100  in this example is distinguishable from the camera modules described above in that the camera module  100  further includes a third housing. In this example, the camera module  100  further includes a third housing  170  accommodating another fixed lens  134 . This example is advantageous in a case in which parts of the camera module  100  are manufactured separately. As an example, this example is advantageous in a case in which the first housing  110  is manufactured in an automatic production line and the third housing  170  is manufactured partially by hand. 
     The camera module  100  in this example is distinguishable from the camera modules described above in terms of an arrangement of the second housing  120 . In this example, the second housing  120  is disposed between the first housing  110  and the third housing  170 . This arrangement is advantageous in a case in which a focusing function is effective due to the lens disposed in the middle. 
     The examples described above enable the camera module to rapidly perform the focusing function. 
     While this disclosure includes specific examples, it will be apparent to one of ordinary skill in the art that various changes in form and details may be made in these examples without departing from the spirit and scope of the claims and their equivalents. The examples described herein are to be considered in a descriptive sense only, and not for purposes of limitation. Descriptions of features or aspects in each example are to be considered as being applicable to similar features or aspects in other examples. Suitable results may be achieved if the described techniques are performed in a different order, and/or if components in a described system, architecture, device, or circuit are combined in a different manner, and/or replaced or supplemented by other components or their equivalents. Therefore, the scope of the disclosure is defined not by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be construed as being included in the disclosure.