Abstract:
A lens barrel assembly, a camera including the lens barrel assembly, and a method of assembling a lens barrel are disclosed. The lens barrel assembly is provided that includes an optical lens, a unitary barrel having an outlet slit defined therethrough, and a flexible printed circuit board extending through the outlet slit to communicate signals between an area inside the barrel and an area outside the barrel.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATION 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 12/649,469 filed on Dec. 30, 2009, which claims the benefit of Korean Patent Application No. 10-2008-0138535 filed on Dec. 31, 2008, in the Korean Intellectual Property Office, the entireties of which are incorporated herein by reference. 
     
    
     BACKGROUND 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to a lens barrel assembly and a camera including the lens barrel assembly. More particularly, the invention relates to a lens barrel assembly having an improved extension structure for extending a flexible printed circuit board (FPCB) configured to transmit signals between the inside and the outside of the lens barrel assembly, and a camera including the lens barrel assembly. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, a camera includes a lens barrel assembly and a camera body. The lens barrel assembly includes an optical lens installed in front of the camera body. The optical lens guides and forms an image of a subject. Also, a lens barrel including the optical lens is installed within in the lens barrel assembly. The lens barrel is driven along an optical axis so as to perform a zooming operation. The lens barrel receives a driving signal from the camera body via a FPCB. 
         [0006]    The FPCB transmits signals between the inside and outside of the lens barrel assembly. In this case, physical interference may be caused during the zooming operation by extension portions that extend inside the lens barrel assembly. This physical interference can thus cause noise and a driving error of a lens barrel assembly. Due to the development of an optical image stabilizing (OIS) correction operation for correcting the adverse effects of a user&#39;s hand shaking while using the camera, the number of wires of the FPCB has increased, thereby increasing the width of the FPCB. Accordingly, adverse effects associated with the above-discussed noise and driving error of a lens barrel assembly FPCB have become more serious. 
         [0007]    Generally, a separate fixing structure for fixing a FPCB to a lens barrel assembly is utilized. This arrangement, however, increases the number of components and associated manufacturing costs. In addition, the fixing structure installed in the lens barrel assembly may limit the extent to which a camera including the lens barrel assembly can be miniaturized. 
       SUMMARY 
       [0008]    The invention provides a lens barrel assembly having an improved extension structure for extending a FPCB configured to transmit signals between the inside and outside of the lens barrel assembly. The invention also provides a camera including the lens barrel assembly, and a method of assembling the lens barrel assembly. 
         [0009]    According to an embodiment of the invention, a lens barrel assembly is provided. The lens barrel assembly includes an optical lens, a unitary barrel having an outlet slit defined therethrough, and a FPCB extending through the outlet slit to communicate signals between an area inside the barrel and an area outside the barrel. 
         [0010]    The outlet slit may be defined along a circumferential direction of the barrel case. 
         [0011]    The barrel may also have an assembly slit defined therethrough, the assembly slit being connected to the outlet slit. 
         [0012]    The assembly slit may connect to a front or rear edge of the barrel to allow the FPCB to slide into and across the assembly slit into the outlet slit during assembly of the lens barrel assembly. 
         [0013]    The lens barrel assembly may include a lens assembly installed and configured to move along an optical axis, wherein the optical lens is installed in the lens assembly. 
         [0014]    An end of the FPCB may be connected to the lens assembly, and another end of the FPCB extend to the area outside the barrel. 
         [0015]    A portion of the FPCB accommodated in the lens barrel assembly may have a length sufficient to accommodate the movement of the lens assembly. 
         [0016]    The outlet slit may be away from any edge of the barrel. 
         [0017]    An edge of the outlet slit may be a rounded curved surface. 
         [0018]    The outlet slit may include a separation blocking stumbling projection formed at an end of the outlet slit. 
         [0019]    The FPCB may have a u-shaped fold corresponding to an edge of the outlet slit. 
         [0020]    According to another embodiment of the invention, a method of assembling a lens barrel including a unitary barrel having an outlet slit and assembly slit defined therethrough, the assembly slit being connected to the outlet slit is provided that includes sliding a FPCB into and across the assembly slit into the outlet slit. 
         [0021]    The method may include forming a u-shaped bend in the FPCB corresponding to an edge of the outlet slit, and engaging an edge of the FPCB with a separation blocking stumbling projected formed at an end of the outlet slit to retain the FPCB in the outlet slit. 
         [0022]    The outlet slit may be defined along a circumferential direction of the barrel away from any edge of the barrel, and the assembly slit may connect to an edge of the barrel to enable the FPCB to slide into the assembly slit. 
         [0023]    The method may include installing a lens assembly including a lens, and coupling an end of the FPCB to the lens assembly. 
         [0024]    According to yet another embodiment of the invention, a camera is provided that includes a camera body, a lens assembly comprising an optical lens installed in the lens assembly and configured to move along an optical axis, a barrel having an outlet slit defined therethrough, and a FPCB extending through the outlet slit to communicate signals between the lens assembly and the camera body. 
         [0025]    The outlet slit may be away from any edge of the barrel. 
         [0026]    The barrel also may also have an assembly slit defined therethrough, the assembly slit being connected to the outlet slit, and the assembly slit connecting to an edge of the barrel to allow the FPCB to slide into and across the assembly slit into the outlet slit during assembly of the lens barrel assembly. 
         [0027]    The FPCB may have a u-shaped fold corresponding to an edge of the outlet slit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0028]    The above and other features and advantages of the invention will become more apparent by describing in detail exemplary embodiments thereof with reference to the attached drawings in which: 
           [0029]      FIGS. 1 through 3  are vertical cross-sectional views of examples of a lens barrel assembly in various states, according to an embodiment of the invention; 
           [0030]      FIG. 4  is a perspective view of an example of a guide barrel in which an outlet slit is formed, according to an embodiment of the invention; 
           [0031]      FIG. 5  is a perspective view illustrating an example of a state in which a FPCB is installed using an outlet slit, according to an embodiment of the invention; 
           [0032]      FIGS. 6 and 7  are perspective views illustrating examples of states in which a FPCB is installed, according to Comparative Examples 1 and 2; 
           [0033]      FIG. 8  is a schematic perspective view of an example of a FPCB configured to transmit signals between a lens assembly and camera body, according to an embodiment of the invention; 
           [0034]      FIG. 9  is a perspective view of an example of a guide barrel in which an outlet slit is formed, according to another embodiment of the invention; and 
           [0035]      FIG. 10  is an enlarged perspective view of an example of a main portion of the example of  FIG. 9 , according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0036]    Hereinafter, a lens barrel assembly and a camera including the lens barrel assembly will be described with regard to exemplary embodiments of the invention with reference to the attached drawings.  FIGS. 1 through 3  are vertical cross-sectional views of examples of a lens barrel assembly  200  in various states, according to an embodiment of the invention. That is,  FIG. 1  is a cross-sectional view of an example of the lens barrel assembly  200  in a state in which the lens barrel assembly  200  is retracted backward when a photographing operation is not being performed.  FIGS. 2 and 3  are cross-sectional views of examples of the lens barrel assembly  200  in states in which the lens barrel assembly  200  is controlled to be in a telephoto state and a wide-angle state, respectively, when the lens barrel assembly  200  is protruded forward. The lens barrel assembly  200  includes first through third lens assemblies L 1 , L 2  and L 3 , and a photoelectric transformer  160 , which are accommodated in the barrel case  100 . 
         [0037]    The barrel case  100  includes a fixed barrel  120  that is fixed to a camera body. The barrel case also includes first and second movable barrels  141  and  142  that extend out of the fixed barrel  120  when a photographing operation is being performed. The fixed barrel  120  may include, for example, a lens base  121  and a guide barrel  130  having a cylindrical shape and disposed at an outermost portion of the lens barrel assembly  200 . The outermost portion is viewed, for example, in a radial direction of the lens barrel assembly  200 . 
         [0038]    The first movable barrel  141  is accommodated in the fixed barrel  120  and is movable in front and rear directions with respect to the fixed barrel  120 . The second movable barrel  142  is accommodated in the first movable barrel  141  and is movable in the front and rear directions with respect to the first movable barrel  141 . The first and second movable barrels  141  and  142  move in the front direction so as to extend out of the fixed barrel  120  when a photographing operation is being performed. Also, the first and second movable barrels  141  and  142  move in the rear direction so as to be accommodated in the fixed barrel  120  when a photographing operation is not performed. The movement of the first and second movable barrels  141  and  142  is guided by cam-followers  125  and  145 . The cam-followers  125  and  145  are provided on a cylindrical surface of the fixed barrel  120  and the first movable barrel  141 . Also, the cam-followers  125  and  145  are provided on a cylindrical surface of the first movable barrel  141  and the second movable barrel  142 . 
         [0039]    The first through third lens assemblies L 1 , L 2  and L 3  may respectively include first through third optical lenses  101 ,  102  and  103 , and first through third fixers  111 ,  112  and  113  for respectively installing the first through third optical lenses  101 ,  102  and  103 . At least one of the first through third lens assemblies L 1 , L 2  and L 3  may perform, for example, zoom-in and zoom-out operations while moving in the front and rear directions along an optical axis ‘O’ so as to perform a transforming operation between the telephoto state and the wide-angle state. 
         [0040]    For example, the second lens assembly L 2  may be connected to a driving motor (not shown) so as to move in the front and rear directions. That is, the second lens assembly L 2  is inserted into a lead screw of a driving shaft  180  extending across an internal space of the lens barrel assembly  200 . When an operational signal is applied to the driving motor (not shown), the driving shaft  180  connected to the same axle of the driving motor rotates, and the second lens assembly L 2  moves in the front and rear directions along the lead screw having a spiral shape and formed on the driving shaft  180 . As illustrated in the example of  FIG. 2 , in the telephoto state, the second lens assembly L 2  moves in the front direction so as to be close to the first lens assembly L 1 . In the wide-angle state, the second lens assembly L 2  moves in the rear direction so as to be close to the third lens assembly L 3 . 
         [0041]    The second lens assembly L 2  may perform, for example, a shake correction operation (that is, an optical image stabilizing (OIS) operation) for correcting a unwanted effects caused by a user&#39;s shaking of a camera by controlling a location of the second optical lens  102 . For example, the second lens assembly L 2  may fix a focal point location of a subject, which is focused on the photoelectric transformer  160 , by moving the second optical lens  102  in a direction perpendicular to the optical axis ‘O’ in proportion to the detected shake of the camera. To achieve this, an actuator (not shown) for moving the second optical lens  102  to a target location may be installed close to the second optical lens  102 . The actuator may include, for example, a voice coil motor (VCM). The shake correction operation may be controlled by an OIS control signal received from the camera body. A shutter S for controlling the amount of light exposed to the photoelectric transformer  160  may be installed in the second lens assembly L 2 . An open/close operation of the shutter S may be performed according to a shutter control signal received from the camera body. A circuit board P for converting the OIS control signal and shutter control signal received from the camera body into appropriate driving signals may be installed in the second lens assembly L 2 . 
         [0042]    A FPCB  150  for transmitting signals between the second lens assembly L 2  and the camera body may be connected to the second lens assembly L 2 , for example, to the circuit board P of the second lens assembly L 2 . The FPCB  150  may transmit, for example, the OIS control signal and the shutter control signal, which control the shake correction operation, between the camera body and the second lens assembly L 2 . 
         [0043]    As illustrated in the examples of  FIGS. 1 through 3 , the FPCB  150  may be flexibly deformed according to the movement of the second lens assembly L 2  connected to an end of the FPCB  150  or a protruding/retracting operation of the lens barrel assembly  200 , and it maintains a stable connection to the second lens assembly L 2 . In addition, the FPCB  150  may have a length sufficient to correspond to a variable location of the second lens assembly L 2 . 
         [0044]    As illustrated in the example of  FIG. 1 , the FPCB  150  extends out of the barrel case  100  from the second lens assembly L 2  through an outlet slit  135  that is formed in the guide barrel  130 . One end of the FPCB  150  is connected to a main circuit board (not shown) installed within the camera body. The outlet slit  135  may be formed away from the rear of the barrel case  100 . For example, the outlet slit  135  may be formed away from the lens base  121  covering the rear of the barrel case  100  in the front direction. The FPCB  150  connected to the second lens assembly L 2  extends towards the guide barrel  130  via the rear of the barrel case  100  and along an inner surface of the lens base  121 . The FPCB  150  extending in the front direction along an inner surface of the guide barrel  130  extends out of the barrel case  100 , and is then folded around the outlet slit  135  so as to surround the guide barrel  130  and extend in the rear direction. 
         [0045]    As described above, the length of the FPCB  150  may be sufficient to correspond to the variable location of the second lens assembly L 2 . As a result, the FPCB  150  may correspond to a variable location of the second lens assembly L 2  by folding or unfolding a portion  150   a  extending along the inner surface of the guide barrel  130  according to the variable location of the second lens assembly L 2  while the FPCB  150  is nearly pivoted in the outlet slit  135 . 
         [0046]    Referring to the example of  FIG. 2 , when the second lens assembly L 2  moves in the front direction, the portion  150   a  of the FPCB  150  extending along the inner surface of the guide barrel  130  is unfolded as the FPCB  150  is drawn by the second lens assembly L 2 . Then, referring to the example of  FIG. 3 , when the second lens assembly L 2  moves in the rear direction, the portion  150   a  of the FPCB  150  is closely adhered to the inner surface of the guide barrel  130  by a self-elastic force of the FPCB  150  while the FPCB  150  that is previously unfolded is folded in a ‘U’ shape. 
         [0047]    The lens barrel assembly  200  illustrated in the examples of  FIGS. 1 through 3  may be assembled with the camera body (not shown) so as to constitute the camera. As illustrated in the examples of  FIGS. 1 through 3 , the lens barrel assembly  200  includes the photoelectric transformer  160  converting an image of a subject into an electric image signal, and the first through third lens assemblies L 1 , L 2  and L 3  for forming an image of the subject on the photoelectric transformer  160 . The camera body may include circuit structures for processing the electrical image signal transmitted from the lens barrel assembly  200 , that is, from the photoelectric transformer  160  and storing the electrical image signal in an appropriate file format. 
         [0048]      FIG. 4  is a perspective view of an example of a guide barrel  130  in which the outlet slit  135  is formed, according to an embodiment of the invention.  FIG. 5  is a perspective view illustrating an example of a state in which the FPCB  150  is installed using the outlet slit  135 , according to an embodiment of the invention. The outlet slit  135  may be formed in the guide barrel  130  along a circumferential direction thereof so as to have a first length D 1 . The first length D 1  of the outlet slit  135  may correspond to the width of the FPCB  150 , and may be sufficiently large to prevent physical interference between the FPCB  150  and edges of the outlet slit  135 , for example. However, the outlet slit  135  is designed to have a size, that is, the first length D 1 , just slightly greater than the width of the FPCB  150 , for example, thereby preventing an exposure of external light to the inside of the guide barrel  130 , that is, the inside of the lens barrel assembly  200 . This also prevents the penetration of external foreign substances from moving inside of the lens barrel assembly  200 . 
         [0049]    An assembly slit  133  together with the outlet slit  135  may be formed, for example, in the guide barrel  130 . The assembly slit  133  may be formed in the front and rear direction of the guide barrel  130  so as to have a second length D 2 . Also, the assembly slit  133  may extend from the rear of the guide barrel  130  to the outlet slit  135  towards the front of the guide barrel  130 . Referring to the example of  FIG. 4 , the assembly slit  133  may be opened towards the rear of the guide barrel  130 . Alternatively, the assembly slit may be opened towards the front of the guide barrel  130 , and may be formed in the guide barrel  130  in the front and rear directions from an opening  130 ′ to the outlet slit  135 . 
         [0050]    When both ends of the FPCB  150  are respectively connected to the second lens assembly L 2  and the main circuit board (not shown), an intermediate portion of the FPCB  150  may be fixed to the guide barrel  130  via the opening  130 ′ of the assembly slit  133 . The portion of the FPCB  150  fixed to the guide barrel  130  may be guided along the assembly slit  133  so as to be accommodated in the outlet slit  135 . 
         [0051]    For example, the assembly slit  133  and the outlet slit  135  may be vertically bent as a whole, wherein ends of the assembly slit  133  and the outlet slit  135  are connected to each other. A cutting portion  131  that is surrounded by the assembly and outlet slits  133  and  135  so as to be cut from the guide barrel  130  may support the portion of the FPCB  150  that extends out of the barrel case  100  through the outlet slit  135 , for example. 
         [0052]    Referring to the example of  FIG. 5 , the FPCB  150  extending out of the barrel case  100  through the outlet slit  135  is supported by the cutting portion  131 , extending in the rear direction, is folded around the rear of the barrel case  100 , and then extends in the front direction, so as to have a ‘U’ shape, for example. 
         [0053]    In the examples of  FIGS. 4 and 5 , the outlet slit  135  and the assembly slit  133  are formed in the guide barrel  130 , but are not limited to such an arrangement. For example, the outlet slit  135  and the assembly slit  133  may be formed in any portion of the barrel case  100  as long as the FPCB  150  extends out of the barrel case  100 , for example. 
         [0054]      FIGS. 6 and 7  are perspective views illustrating examples of states in which a FPCB  50  is installed, according to Comparative Examples 1 and 2, respectively. Referring to the examples of  FIGS. 6 and 7 , press forming materials  40  and  40 ′ for supporting the FPCB  50  are disposed in lens barrel assemblies  30  and  30 ′, respectively. As illustrated in the example of  FIG. 6 , the FPCB  50  is folded along the press forming material  40  in a ‘∩’ shape, and extends out of the lens barrel assembly  30  via the rear of the lens barrel assembly  30 . The FPCB  50  is folded along the press forming material  40  so as to correspond to a variable location of a lens assembly. In Comparative Examples 1 and 2, it is necessary to manufacture and assemble the press forming materials  40  and  40 ′ for supporting the FPCB  50 , and the press forming materials  40  and  40 ′ are installed in the lens barrel assemblies  30  and  30 ′, thereby causing physical interference between the press forming materials  40  and  40 ′ and movable members such as a lens assembly, and also causing noise due to the physical interference. In addition, when a moving axis is distorted, or an error arises in terms of locations of the press forming materials  40  and  40 ′, both the resulting physical interference and the resulting noise may become more serious. In particular, along with the user&#39;s requirements for small-sized barrels, interference due to the press forming materials  40  and  40 ′ may also become more serious. 
         [0055]    The FPCB  150  is supported by forming the outlet slit  135  in the lens barrel assembly  200 , in other words, in the guide barrel  130  of the lens barrel assembly  200 , as illustrated in the example of  FIG. 4 . Accordingly, manufacturing costs may be reduced by as much as those required to manufacture the press forming materials  40  and  40 ′. An assembly process for the press forming materials  40  and  40 ′ may be omitted. As a result, the associated assembly costs may decrease. In addition, in the example of  FIG. 4 , there is no noise and physical interference between the press forming materials  40  and  40 ′ and surrounding members. 
         [0056]      FIG. 8  is a schematic perspective view of an example of the FPCB  150  of  FIGS. 1 through 3 , according to an embodiment. The FPCB  150  extends in an ‘A’ direction towards the second lens assembly L 2 , and it extends in a ‘B’ direction towards the main circuit board of the camera body. The FPCB  150  may thus transmit the OIS control signal for controlling the shake correction operation and the shutter control signal for controlling the open/close operation of the shutter S between the camera body and the second lens assembly L 2 , for example. The FPCB  150  includes a plurality of signal patterns (not shown) for transmitting the respective different control signals. A contact portion  155  of the FPCB  150  having an electrical contact point with respect to the main circuit board is formed so as to have a wide width W so that the signal patterns have a sufficient pitch. 
         [0057]    If the size, that is, the first length D 1 , of the outlet slit  135  is increased in order to correspond to the width W of the contact portion  155 , light leakage and penetration of external foreign substances may occur. As illustrated in the example of  FIG. 4 , by forming the assembly slit  133  in the lens barrel assembly  200 , that is, in the guide barrel  130  of the lens barrel assembly  200 , the intermediate portion of the FPCB  150  may be fixed to the lens barrel assembly  200 , that is, to the guide barrel  130  of the lens barrel assembly  200  without regard to the width W of the contact portion  155 . The assembly slit  133  may facilitate assembly of the FPCB  150  including the contact portion  155  having the width W. 
         [0058]      FIG. 9  is a perspective view of a guide barrel  330  in which an outlet slit  335  is formed, according to another embodiment of the invention. Referring to the example of  FIG. 9 , the outlet slit  335  for extending the FPCB  150  out of a barrel case is formed in the guide barrel  330  along a circumferential direction thereof. An assembly slit  333  is formed in the guide barrel  330  in the front and rear directions and extends towards the outlet slit  335 . 
         [0059]      FIG. 10  is an enlarged perspective view of an example of a main portion of the example of  FIG. 9 , according to an embodiment of the invention. Referring to the example of  FIG. 10 , a separation blocking stumbling projection  338  for blocking separation of the FPCB  150  is formed at an open end of the outlet slit  335 . The separation blocking stumbling projection  338  may protrude from an inner surface of the outlet slit  335  to the inside of the outlet slit  335 . The separation blocking stumbling projection  338  may fix an assembly location of the FPCB  150  supported by the outlet slit  335 , for example. 
         [0060]    When the FPCB  150  supported by the outlet slit  335  comes into contact with the inner surface of the outlet slit  335 , physical interference such as friction may occur due to a contact portion between the FPCB  150  and the inner surface of the outlet slit  335 , for example. By forming a rounded curved surface R at an edge of the inner surface of the outlet slit  335 , damage to the FPCB  150  due to the friction may be minimized. 
         [0061]    According to the invention, noise and driving error of a lens barrel assembly may be minimized by improving an extension structure for extending a FPCB configured to transmit signals between the inside and outside of a lens barrel assembly. 
         [0062]    In addition, because a separate assembly structure for fixing the FPCB to the lens barrel assembly is not required, the overall number of components and associated manufacturing costs may be reduced. In addition, a lens barrel assembly that is appropriate for a small-sized camera may be provided. 
         [0063]    While the invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the following claims.