Abstract:
A lens adjusting device ( 100 ) includes an optical module ( 10 ) and a driver module ( 20 ). The driver module includes a seat ( 22 ), at least one magnet ( 24 ) and at least one winding ( 26 ). The optical module is rotatablly fixed on the seat. The magnet is fixed on the optical module. The magnet and the winding are positioned at one side of the optical module. A variable current is applied to the winding, and a magnetic field is formed at ends of the winding. The magnetic forces between the magnetic field and the magnet drives the optical module to rotate.

Description:
BACKGROUND 
       [0001]    1. Field of the Invention 
         [0002]    The present invention generally relates to cameras and, particularly, to a lens adjusting device and an image tracking system with the lens adjusting device. 
         [0003]    2. Description of Related Art 
         [0004]    Cameras are widely used and have brought convenience to our lives. In short, cameras have become a part of modern life. Several cameras are used for electronic video communication. In video communication, seeing the face of the other user is important. However, most conventional cameras do not move automatically to track a user&#39;s face. The user has to specially move the camera by hand to re-enter the field of view, or has to consciously move his or her face back into the field of view of the camera. 
         [0005]    Therefore, there is room for improvement within the art. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the lens adjusting device can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the lens adjusting device. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views, in which: 
           [0007]      FIG. 1  is a block diagram of an image tracking system including a lens adjusting device and a data processing module in an exemplary embodiment; 
           [0008]      FIG. 2  is a schematic view of the lens adjusting device shown in  FIG. 1 ; 
           [0009]      FIG. 3  is similar to  FIG. 2 , but showing the lens adjusting device at a first working position; and 
           [0010]      FIG. 4  is similar to  FIG. 2 , but showing the lens adjusting device at a second working position. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0011]      FIG. 1  shows a block diagram of an image tracking system  300  according to an exemplary embodiment. The image tracking system  300  includes a lens adjusting device  100  and a data processing module  200 . The lens adjusting device  100  includes an optical module  10  and a driver module  20  that are physically connected to each other. The optical module  10  is used to capture images, and the driver module  20  is configured for rotating the optical module  10  to track an image object (e.g., face of a user). 
         [0012]    The data processing module  200  processes the image data from the lens adjusting device  100  and controls the movement of the optical module  10 . The data processing module  200  includes a machine vision module  30  and a movement controlling module  40  electronically connected to the lens adjusting device  100 . The machine vision module  30  tracks the location of the image object according to the image data fed and received from the optical module  10 . Also, the machine vision module  30  can compare the present location of the image object to the original location of the image object, calculating the displacement of the image object. The machine vision module  30  sends the data corresponding to the displacement of the image object to the movement controlling module  40 , and then the movement controlling module  40  decides whether, and how much, to move the optical module  10 . 
         [0013]    The optical module  10 , the driver module  20 , the machine vision module  30  and the movement controlling module  40  work together, to track the image object. For example, when tracking a face of the user, the optical module  10  records image data of the left eye, the right eye and the nose of the user. The left eye, the right eye and the nose are considered as three points, and a triangle is formed when the three points are linked. The recorded data is then sent to the machine vision module  30 . The machine vision module  30  receives the data from the optical module  10 , and calculates the location of a center point of the triangle. When the face moves, the location of the center point of the triangle correspondingly moves. The machine vision module  30  calculates the displacement of the center point of the triangle and sends a signal indicative of the movement to the movement controlling module  40 . The movement controlling module  40  calculates a rotation angle of the optical module  10  according to the movement of the object. The driver module  20  receives the instructions from the movement controlling module  40 , and moves the optical module  10  to track the movement of the user (e.g. face the face of the user). 
         [0014]      FIG. 2  shows a schematic view of the lens adjusting device  100  including the optical module  10  and the driver module  20 . The optical module  10  includes a base  12  and a lens  14 . The base  12  and the lens  14  may be column-shaped. The lens  14  is typically mounted on a center area of a top surface  124  of the base  12  for rotational symmetry. The base  12  has a round hole  122  defined in a center portion thereof. 
         [0015]    The driver module  20  includes a seat  22 , two magnets  24  and two windings  26 . The seat  22  is generally a box with an open end. A shaft  222  is formed on one sidewall of the seat  22 , configured for matching with the round hole  122  of the base  12 . The optical module  10  is rotatable relative to the shaft  222  of the seat  22  by engagement of the shaft  222  and the round hole  122 . Two columns  224  respectively extend from opposite sidewalls of the seat  22 , positioned at two sides of the optical module  10 . An axis of each column  224  is substantially at a same height as the shaft  222 , and is perpendicular to the longitudinal axis of the shaft  222 . Each magnet  24  has a rectangular section, and is positioned on the top surface  124  of the base  12 . The magnets  24  are respectively positioned at both sides of the lens  14 . The windings  26  are respectively wrapped around the columns  224 , connecting to a power source (not shown). When current is not flowing, the windings  26  are do not create a magnetic field, and the optical module  10  is in balanced position. When current is flowing, the windings  26  create a magnetic field, and the optical module  10  rotates in a certain angle according to the direction and strength of the magnetic fields created by the windings  26 . 
         [0016]    Referring to  FIG. 3 , When the image object moves left relative to the optical module  10 , the machine vision module  30  sends a data of displacement of the image object to the movement controlling module  40 . The movement controlling module  40  decides a rotation angle of the optical module  10  according to the displacement of the object. The driver module  20  receives the data from the movement controlling module  40 , and controls the strength and direction of the current to the windings  26 . A magnetic field is formed at one end of the winding  26 . According to the “right-hand rule”, the magnetic force of one end of the left winding  26  is opposite to that of an adjacent end of the left magnet  24 , and the magnetic pole of one end of the right winding  26  is similar to an adjacent end of the right magnet  24 . Like magnetic poles repel, unlike magnetic poles attract, the optical module  10  turns left in a certain angle, so as to track the object. 
         [0017]    Referring to  FIG. 4 , when the object moves right relative to the optical module  10 , the direction of the current of the windings  26  is opposite to above. The magnetism of one end of the right winding  26  is opposite to that of an adjacent end of the right magnet  24 , and the magnetic pole of one end of the left winding  26  is similar to an adjacent end of the left magnet  24 . The optical module  10  turns right to track the object. 
         [0018]    It is to be understood that one magnet  24  and the corresponding winding  26  may be omitted. Also, the number of the magnetisms and the windings  26  may increase at the same time. 
         [0019]    Image tracking system  300  may be used with the following method for capturing images, comprising: providing a rotatable optical module for capturing images; feeding image data to a data processing module; using the data processing module to determine whether the subject of the images has moved; using a driver module electronically connected to the data processing module and physically connected to the optical module for moving the optical module to track a moving subject. 
         [0020]    It is to be further understood that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.