Patent Publication Number: US-2007110433-A1

Title: Shutter driving apparatus for camera module

Description:
CLAIM FOR PRIORITY  
      This application claims priority to an application entitled “Shutter driving apparatus for camera module” filed in the Korean Intellectual Property Office on Nov. 17, 2005 and assigned Serial No. 2005-110052, the contents of which are hereby incorporated by reference.  
     BACKGROUND  
      1. Field of the Invention  
      The present invention relates to a construction for sliding shutter blades, and more particularly, to a shutter driving apparatus for a camera module, which slidingly moves shutter blades provided to a camera lens module in both sideward directions so as to open and close a lens opening.  
      2. Description of the Related Art  
      As is generally known in the art, a camera module is used in a video camera, an electronic still camera, a PC camera terminal, a camera phone, and so on, to recognize an image.  
      These days, as the sizes of a camera module and a photographed image shrink with the development of high precision technologies, various camera modules have been disclosed in the art, which are miniaturized so that a user can photograph an object while holding each camera module in the hand and without the aid of a tripod, etc.  
      In this regard, recently, by mounting a camera module to a portable terminal, it becomes possible to implement visual conversation with a counterpart or take a still image or a moving picture of an object which is desired to be photographed.  
      Therefore, a portable terminal which serves as a medium for transmitting voices and letters has been changed to a high performance complex instrument equipped with a camera module capable of momentarily capturing, storing and transmitting a current image.  
      In a camera module, the iris of a camera lens and a shutter blade are usually installed to be overlapped with each other.  
      Describing a construction of a conventional camera module  1  with reference to  FIGS. 1 and 2 , the camera module  1  comprises a lens housing  2 , a circuit board (not shown) arranged in the lens housing  2 , a camera lens module  3  provided to the circuit board, a shutter blade  5  installed over the lens of the camera lens module  3  to be rotated about an axis ‘A 1 ’ in forward and backward directions to thereby open and close a lens opening  4 , and a shutter driving section  6  installed on one end of the shutter blade  5  and provided with an electromagnet (not shown) to create a magnetic field and rotate the shutter blade  5  as currents are applied to the electromagnet.  
      The lens housing  2  has the shutter driving section  6  and the shutter blade  5  and defines a space in which the shutter blade  5  can be rotated.  
      However, a drawback of the conventional shutter driving apparatus for the camera module, constructed as described above, is that, since the camera module  1  must define the space in which the shutter blade  5  can be rotated to open and close the lens opening  4 . This constitutes a limitation in decreasing the size and volume of the camera module  1 . Miniaturization and slimness of the camera module is concomitantly limited.  
     SUMMARY OF THE INVENTION  
      The present invention has been made to solve the above-mentioned problems occurring in the prior art, and the present invention, in one aspect, provides a shutter driving apparatus for a camera module, in which a pair of shutter driving sections are constructed to slidingly move shutter blades provided to a camera lens module in both sideward directions to thereby open and close a lens opening. The space required to install the shutter driving apparatus in the camera lens module can, as a result, be reduced, and miniaturization and slimness of the camera module can be ensured.  
      In another aspect, the present invention provides a shutter driving apparatus for a camera module, in which a pair of shutter driving sections are constructed to slidingly move shutter blades provided to a camera lens module, using wires in both sideward directions to thereby open and close a lens opening. Opening and closing operations of the shutter blades is easily implemented according to this design.  
      A first embodiment of the present invention, according to the first above-described aspect, comprises a shutter driving apparatus for a camera lens module that includes a lens housing; a pair of shutter blades provided to the lens housing to be slidingly moved in a lengthwise direction of the lens housing to thereby open and close a lens opening of the camera lens module; and a pair of shutter driving sections respectively connected to the shutter blades via rotation links, the sections each having an electromagnet and a permanent magnet positioned between the poles of the electromagnet such that the permanent magnet is rotated due to a magnetic field created as current is applied to the electromagnet, to slidingly move an associated shutter blade.  
      A second embodiment of the present invention directed to achieving the second above-described aspect comprises a shutter driving apparatus, for a camera lens module, that includes a lens housing; first and second shutter blades provided to the lens housing to be slidingly moved in a lengthwise direction of the lens housing to thereby open and close a lens opening of the camera lens module; a shutter driving section connected to the first shutter blade via a rotation link and having an electromagnet and a permanent magnet connected to the rotation link and positioned between the poles of the electromagnet such that the permanent magnet is rotated due to a magnetic field created as current is applied to the electromagnet, to slidingly move the shutter blades; and at least one wire winding means for winding and unwinding wires which respectively connect the first and second shutter blades to the shutter driving section, when the shutter driving section is operated, and for thereby slidingly moving the shutter blades. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The above features and advantages of the present invention will be more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:  
       FIG. 1  is a perspective view illustrating a conventional shutter driving apparatus for a camera module;  
       FIG. 2  is a plan view illustrating an operating state of the conventional shutter driving apparatus for a camera module;  
       FIG. 3  is an exploded perspective view illustrating a construction of a shutter driving apparatus for a camera module in accordance with a first embodiment of the present invention;  
       FIG. 4  is an exploded perspective view illustrating the assembled state of shutter blades in the construction of the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention;  
       FIG. 5  is a perspective view illustrating the assembled state of the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention;  
       FIG. 6  is a plan view illustrating a state before the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention is operated;  
       FIG. 7  is a perspective view illustrating an operation pattern of the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention;  
       FIG. 8  is a plan view illustrating the operation pattern of the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention;  
       FIG. 9  is a perspective view illustrating a state after the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention is operated;  
       FIG. 10  is a plan view illustrating the state after the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention is operated;  
       FIG. 11  is a perspective view illustrating a variation of the shutter blades in the construction of the shutter driving apparatus for a camera module in accordance with the first embodiment of the present invention;  
       FIG. 12  is an exploded perspective view illustrating a construction of a shutter driving apparatus for a camera module in accordance with a second embodiment of the present invention;  
       FIG. 13  is a partially cut-away perspective view illustrating the assembled state of shutter blades in the construction of the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention;  
       FIG. 14  is a perspective view illustrating the assembled state of the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention;  
       FIG. 15  is a plan view illustrating a state before the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention is operated;  
       FIG. 16  is a perspective view illustrating an operation pattern of the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention;  
       FIG. 17  is a plan view illustrating the operation pattern of the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention;  
       FIG. 18  is a perspective view illustrating a state after the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention is operated; and  
       FIG. 19  is a plan view illustrating the state after the shutter driving apparatus for a camera module in accordance with the second embodiment of the present invention is operated. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIGS. 3 and 4 , a shutter driving apparatus  10  for a camera module in accordance with a first embodiment of the present invention comprises a lens housing  20 , a pair of shutter blades commonly represented by the reference numeral  30 , and a pair of shutter driving sections  40 . The lens housing  20  is configured to allow the shutter blades  30  to be slidingly moved therein. The shutter blades  30  are provided in the lens housing  20  so that they can be slidingly moved along the lengthwise direction of the lens housing to open and close a lens opening  4  of a lens module  3 . The pair of shutter driving sections  40  are connected to the shutter blades  30  by respective rotation links  50  and are placed below the shutter blades  30 . Each shutter driving section  40  has an electromagnet  41  and a permanent magnet  42  positioned between the poles of the electromagnet. The permanent magnet  42  is connected to the rotation link  50  and is rotated by a magnetic field, created as current is applied to the electromagnet  41 , to slidingly move the shutter blade  30  associated therewith.  
      Referring to  FIGS. 4 and 5 , one end  51  of each rotation link  50  is connected to the shutter blade  30  to transmit the rotation force of the permanent magnet  42  to the shutter blade, and the other end  52  of the rotation link is connected to the permanent magnet  42 . The shutter blade  30  and the permanent magnet  42  are defined with connection holes  60  for allowing the ends of the rotation link  50  to be fitted therein.  
      Referring to  FIGS. 5, 6  and  9  and as seen horizontally along the axis of the lens opening  4  with the lengthwise direction of the lens housing  20  being horizontal, the shutter blades  30  can be slidingly moved in both leftward and rightward directions.  
      Referring to  FIGS. 7 and 9 , one shutter blade  31  is formed with an engagement portion  31   a , and the other shutter blade  32  is defined with an engagement groove  32   a . The engagement portion  31   a  can be engaged within or disengaged from, the engagement groove  32   a  when the shutter blades  30  are slidingly moved.  
      The engagement portion  31   a  and the engagement groove  32   a  have a semicircular profile.  
      Referring to  FIGS. 3, 6 ,  8  and  10 , each shutter driving section  40  comprises the electromagnet  41  and the permanent magnet  42 . Each of the electromagnets  41  has a coil for creating a magnetic field, as current is applied to the coil. Each electromagnet  41 , upon application of the current, has opposite north (N) and south (S) polarities to produce magnetic force. The electromagnet  41  has two ends that serve as poles of opposite polarity, the magnetic force existing in a direction from one of the poles to the other. The permanent magnet  42  is positioned between the pair of poles to thereby be rotated by the magnetic force.  
      Although the drawings show a single, integral electromagnet  41  with two opposite poles between which the permanent magnet  42  is disposed, it is within the intended scope of the invention that the two, opposite poles may belong correspondingly to separate electromagnets magnetized by the same or separate coils. The separate electromagnets could collectively consist of two electromagnets whose inner poles face each other and are disposed within the coil, for example.  
      A first preferred embodiment of the present invention provides each of the sections  40  being configured for creating a pair of electromagnetically-opposite electromagnetic poles. Each section  40  also has a permanent magnet connected to the rotation link  50  and positioned between the poles such that the permanent magnet  42  is rotated due to a magnetic field created as current is applied to an electromagnet, to slidingly move an associated shutter blade  31 ,  32 .  
      Hereinafter, an operational procedure of the shutter driving apparatus for a camera module according to the first preferred embodiment of the present invention, constructed as mentioned above, is described in detail with reference to  FIGS. 3 through 11 .  
      Referring to  FIGS. 3 and 4 , the shutter driving apparatus  10  for a camera module includes the lens housing  20 , the pair of shutter blades  31 ,  32 , and the pair of shutter driving sections  40 .  
      The pair of shutter driving sections  40  are provided in the lens housing  20  in the lengthwise direction of the lens housing, and the pair of shutter blades  30  are respectively disposed above the shutter driving sections  40 .  
      Referring to  FIG. 4 , the pair of shutter blades  31 ,  32  are positioned above the lens opening  4  which is defined in the lens housing  20 . At this time, as can be readily seen from  FIG. 5 , one end  51  of the rotation link  50  is rotatably fitted into the connection hole  60  which is defined in the shutter blade  30 . The other end  52  of the rotation link  50  is fixedly fitted into the connection hole  60  which is defined in the permanent magnet  42  of the shutter driving section  40 .  
      In this state, as shown in  FIGS. 5, 7  and  9 , when it is necessary to operate the pair of shutter blades  31 ,  32 , current is applied to the electromagnet  41  which is located adjacent to the lens opening  4 .  
      This magnetizes the electromagnet  41  into N and S polarities at respective poles to produce magnetic force, as seen in  FIG. 6  for example.  
      As seen in the sequence of  FIGS. 6, 8  and  10 , the magnetic force rotates, in a counterclockwise direction, the permanent magnet  42  positioned between the pair of poles. Due to the fact that the permanent magnet  42  is securely connected to the rotation link  50 , rotation of the permanent magnet integrally rotates the rotation link  50 . At the same time, as seeable with the lens housing  20  disposed horizontally so that the axis of the lens opening  4  is in the line of sight, the pair of shutter blades  31 ,  32  are slidingly moved outwardly in both sideward directions.  
      As can be readily seen from  FIGS. 7 and 9 , at the same time the shutter blades  31 ,  32  are slidingly moved outwardly, the engagement portion  31   a  formed on one shutter blade  31  is disengaged from the engagement groove  32   a  defined in the other shutter blade  32 .  
      As shown in  FIG. 10 , as the shutter blades  31 ,  32  are slidingly moved outwardly in the sideward directions, the lens opening  4  is opened.  
      Then, as can be seen from  FIGS. 7 and 8 , current is applicable again to the electromagnet  41  in the reverse direction. By changing current direction, the S and N polarities of the electromagnet  41  are reversed (not shown) so that magnetic force is produced in the reverse direction. This likewise rotates the permanent magnet  42  in the reverse direction, i.e., clockwise direction. The rotation link  50  is correspondingly rotated in the reverse direction integrally with the permanent magnet  42 . As a result, the pair of shutter blades  31 ,  32  are slidingly moved inwardly in the sideward directions to close the lens opening  4 .  
      Referring to  FIG. 4 , at the same time the shutter blades  31 ,  32  are slidingly moved inwardly toward each other, the engagement portion  31   a  formed on the shutter blade  31  is engaged into the engagement groove  32   a  defined in the other shutter blade  32 .  
      Here, as described above, the engagement portion  31   a  and engagement groove  32   a  of the shutter blades  31 ,  32  have a semicircular profile to ensure easy engagement.  
      The shutter blades  30 , according to a variation of the first embodiment of the present invention may alternatively, as shown in  FIG. 11 , have a square-shaped configuration.  
      Hereinbelow, an operational procedure of the shutter driving apparatus for a camera module according to a second preferred embodiment of the present invention is described in detail with reference to  FIGS. 12 through 19 .  
      Referring to  FIGS. 12 and 13 , a shutter driving apparatus  10  for a camera module comprises a lens housing  20 , first and second shutter blades  31 ,  32 , a shutter driving section  40 , and at least one wire winding means  100 .  
      Referring to  FIG. 14 , the shutter driving section  40  is provided in the lens housing  20  in the lengthwise direction of the lens housing, and the first and second shutter blades  31 ,  32  are disposed above the shutter driving section  40 . The first and second shutter blades  31 ,  32  are positioned above the lens opening  4  which is defined in the lens housing  20 .  
      One end  51  of the rotation link  50  is rotatably fitted into the connection hole  60  which is defined in the first shutter blade  31 , and the other end  52  of the rotation link  50  is fixedly fitted into the connection hole  60  which is defined in the permanent magnet  42  of the shutter driving section  40 .  
      As shown in  FIG. 13 , the wire winding means  100  is composed of first and second wires  101 ,  102  and at least one roller part  103 . In this preferred embodiment, the roller part  103  comprises first, second and third roller parts  103   a ,  103   b ,  103   c . The first wire  101  has one end  101   a  which is connected to an end of the first shutter blade  31  and the other end  101   b  which is connected to a widthwise middle portion of the second shutter blade  32 . The second wire  102  has one end  102   a  which is connected to the rotation link  50  and the other end  102   b  which is connected to an end of the second shutter blade  32 .  
      Referring to  FIGS. 14, 16  and  18 , when it is necessary to operate the first and second shutter blades  31 ,  32 , current is applied to the electromagnet  41  which is located adjacent to the lens opening  4 . This magnetizes the electromagnet  41  into N and S polarities to produce magnetic force. Due to the magnetic force, the permanent magnet  42  positioned between the pair of opposite poles rotates in a forward, i.e., counterclockwise, direction, as seen from the sequence of  FIGS. 14, 16  and  18 .  FIGS. 15, 17  and  19  likewise show the counterclockwise rotation sequence.  
      Referring to  FIGS. 15 and 17 , due to the fact that the permanent magnet  42  is securely connected to the rotation link  50 , rotation of the permanent magnet integrally rotates the rotation link  50 . At the same time, the first shutter blade  31  is slidingly moved in the lengthwise direction of the lens housing  20 .  
      At this time, as shown in  FIG. 19 , one end  101   a  of the first wire  101  connected to the first shutter blade  31  is moved in the sliding direction of the first shutter blade  31 . The first wire  101  is moved on the first roller parts  103   a  which are located adjacent to the second shutter blade  32 . The first roller parts  103   a  change the sliding movement direction of the first wire  101  and slidingly move the second shutter blade  32  which is connected to the other end  101   b  of the first wire  101 . At this time, one end  102   a  of the second wire  102  which is connected to the second roller part  103   b  of the rotation link  50  is rotated in the forward direction. By this fact, the second wire  102  which is wound on the second roller part  103   b  of the rotation link  50  is unwound from the second roller part.  
      Due to the fact that the other end  102   b  of the second wire  102  is connected to the second shutter blade  32 , at the same time the second wire is unwound from the second roller part  103   b , the other end  102   b  of the second wire is moved on the third roller parts  103   c  which are located adjacent to the first shutter blade  31 .  
      Therefore, referring to  FIGS. 17 and 19 , as the second wire  102  is unwound from the second roller part  103   b , the second shutter blade  32  can be slidingly moved.  
      As a consequence, referring to  FIG. 18 , as the first and second shutter blades  31 ,  32  are slidingly moved, the lens opening  4  is opened.  
      At the same time the shutter blades  31 ,  32  are slidingly moved, the engagement portion  31   a  formed on the first shutter blade  31  is disengaged from the engagement groove  32   a  defined in the second shutter blade  32 .  
      Then, as can be readily seen from  FIGS. 16 and 17 , current is again applicable to the electromagnet  41  in the reverse direction. By changing the direction of the current, the S and N polarities of the electromagnet  41  are reversed (not shown). The permanent magnet  42  is correspondingly rotates in the reverse, i.e., clockwise, direction.  
      By this action, as shown in  FIG. 15 , the rotation link  50  is also rotated clockwise integrally with the permanent magnet  42 , and the first shutter blade  31  is slidingly moved inwardly.  
      Referring to  FIG. 17 , as the rotation link  50  is rotated, the rotation link  50  winds one end  102   a  of the second wire  102  on the second roller part  103   b . The second wire  102  is correspondingly moved on the third roller parts  103   c , and the second shutter blade  32  connected to the other end  102   b  of the second wire  102  is slidingly moved inwardly.  
      Referring to  FIG. 14 , as the first and second shutter blades  31 ,  32  are moved inwardly, the lens opening  4  is closed.  
      Referring to  FIGS. 12 and 13 , a first guide groove  301  for guiding movement of the second wire  102  is defined on an edge of the first shutter blade  31  to extend in the lengthwise direction of the first shutter blade. A second guide groove  302  for guiding movement of the first wire  101  is defined on an edge of the second shutter blade  32  to extend in the lengthwise direction of the second shutter blade. As shown in  FIGS. 12 and 13 , these two edges are preferably opposite.  
      As is apparent from the above descriptions, the shutter driving apparatus for a camera module according to the present invention provides advantages in that, since a pair of shutter driving sections are constructed to slidingly move shutter blades provided to a camera lens module in both sideward directions to thereby open and close a lens opening, a space required to install the shutter driving apparatus in the camera lens module can be reduced, thereby affording increased miniaturization and slimness of the camera module.  
      While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled 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 appended claims.