Abstract:
A filter driving apparatus for a camera is described. The filter driving apparatus comprises a casing, a sliding portion, a magnetic body, and a coil portion. A viewing hole is formed on the central top area of the casing. A sliding channel is formed on the top and bottom area of the casing. The sliding portion slides in the sliding channel. A filter is set on the sliding portion and on the top area of the casing. The magnetic body is set on the bottom area of the casing. The magnetic body connects with the sliding portion. The coil portion is set on the bottom area of the casing. The coil portion generates a pole different from or the same with the magnetic body by inputting different currents, so that a repelling force or an engaging force is generated between the magnetic body and the coil portion. Therefore, the magnetic body could leave from or close to the coil portion, and the filter could be overlapped or removed from the viewing hole.

Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a filter driving apparatus and, more particularly, to a filter driving apparatus for a camera.  
       BACKGROUND OF THE INVENTION  
       [0002]     A filter for use with cameras is typically attached to the front of the camera lens. The filter is to insulate stray light and infrared rays (IR) cut. The light captured by the camera lens during the day may be too much such that it causes overexposed image; hence the filter is necessary for filtering invisible light like ultraviolet or infrared rays. When a picture is taken during the night, the light may be insufficient and even the light energy which can not be seen by eyes may increase the image resolution as well. Therefore, there is no need to filter light. The filter is not necessary and can be removed from the camera lens.  
         [0003]     Referring to  FIG. 8 , a perspective drawing illustrates a conventional filter driving apparatus. The filter driving apparatus  80  comprises a casing  82 , a sliding slice  88  and a driving motor  92 . The casing  82  is a lamellar structure. A viewing hole  84  is set at a side of the casing  82 . First fixing blocks  86  are set on a top and a bottom side of the casing  82  for fixing on the camera (not shown). In addition, second fixing blocks  96  are set at two sides of the casing  82 . The sliding slice  88  can be set on the casing  82  by using a sliding way when the sliding slice  88  is held by the second fixing blocks  96 . The sliding slice  88  has two viewing holes, wherein a filter  90  is set in one viewing hole. The driving motor  92  is set at the bottom side of the casing  82 . A linkage  94  is set in a central axial of the driving motor and is connected to the sliding slice  88 . The sliding slice  88  is then driven to move.  
         [0004]     Referring to  FIG. 9 , a perspective drawing illustrates the conventional filter driving apparatus is in use. The linkage  94  is used by the driving motor  92  to drive the sliding slice  88  while a filter  90  is applied during the day. The viewing hole corresponding to the filter  90  can be aimed at the viewing hole  84  of the casing  82 , so as to provide a filter motion for the camera lens. When the filter  90  is not in use during the night, the sliding slice  88  is driven by the driving motor  92 . The viewing hole without the filter  90  can be aimed at the viewing hole  84  of the casing  82 . The filter motion is therefore unnecessary.  
         [0005]     However, the volume of the driving motor  92  is bigger. The driving motor  92  is too heavy and is impractical, as observed from a comparison with the volume of the casing  92 . Moreover, the location for the camera placing and application is restricted as well. A filter driving apparatus with smaller volume must be provided to reduce the volume of the camera effectively. The filter driving apparatus is then placed into various spaces.  
       SUMMARY OF THE INVENTION  
       [0006]     Accordingly, the object of the present invention is to provide a filter driving apparatus that is applied for a camera. The filter can be moved by using the attractive force and the repulsive force between magnetic materials, so as to decrease volumes taken by the camera.  
         [0007]     In accordance with the present invention the filter driving apparatus comprises a casing, a sliding portion, a magnetic body and a coil portion. A central top area of the casing has a viewing hole. A sliding channel is formed on a top and a bottom side of the casing. The sliding portion can be slid on the sliding channel. A filter is set on the sliding portion. The magnetic body is connected to the sliding portion. A magnetic field is generated that is the same as or differs from the polarity of the magnetic body when different current passes through the coil portion. An attractive force or the repulsive force is then generated between the coil portion and the magnetic body to attract or repel the magnetic body, thereby placing or withdrawing the filter from over the viewing hole.  
         [0008]     Another object of the present invention is to provide a filter driving apparatus for a camera. The filter driving apparatus comprises a casing, a sliding portion, a magnetic body and a coil portion. A viewing hole is set upon a central top area of the casing. The position of the viewing hole corresponds to a camera lens of the camera. A sliding channel is formed on a top and a bottom side of the casing. The sliding portion can be slid on the sliding channel. A filter is set on the sliding portion. The magnetic body is connected to the sliding portion. A magnetic field is generated that is the same as or differs from the polarity of the magnetic body when the coil portion is electrified by different current. An attractive force or a repulsive force is then generated between the coil portion and the magnetic body to attract or repel the magnetic body to leave or inset the coil portion. Therefore, the filter can be placed over or removed from the viewing hole.  
         [0009]     An axial of the coil portion parallels an axial of the magnetic body. If a polarity of the magnetic body is the same as a polarity of a magnetic field generated by the coil portion, an attractive force is then generated between the coil portion and the magnetic body to attract the magnetic body to move toward the coil portion. The filter is then placed over and overlapped the viewing hole. If the polarity of the magnetic body differs from the polarity of the magnetic field generated by the coil portion, a repulsive force is then generated between the coil portion and the magnetic body to repel the magnetic body to withdraw from the coil portion. The filter is then removed from the viewing hole.  
         [0010]     Other features and advantages of the present invention and variations thereof will become apparent from the following description, drawings, and claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  is a schematic diagram illustrating a filter driving apparatus according to a preferred embodiment of the present invention;  
         [0012]      FIG. 2  is a perspective drawing illustrating a filter driving apparatus removing a cover portion according to a preferred embodiment of the present invention;  
         [0013]      FIG. 3  is a side elevation view illustrating a filter driving apparatus according to a preferred embodiment of the present invention;  
         [0014]      FIG. 4  is a decomposition diagram illustrating a filter driving apparatus according to a preferred embodiment of the present invention;  
         [0015]      FIG. 5  is a pictorial drawing illustrating in a filter driving apparatus when the filter is not in use according to a preferred embodiment of the present invention;  
         [0016]      FIG. 6  is a pictorial drawing illustrating in a filter driving apparatus when the filter is in use according to a preferred embodiment of the present invention;  
         [0017]      FIG. 7  is a perspective drawing illustrating a filter driving apparatus within a camera according to a preferred embodiment of the present invention;  
         [0018]      FIG. 8  is a perspective drawing illustrating a conventional filter driving apparatus;  
         [0019]      FIG. 9  is a perspective drawing illustrating a conventional filter driving apparatus is in use;  
         [0020]      FIG. 10  is a perspective drawing illustrating a filter driving apparatus according to a preferred embodiment of the present invention;  
         [0021]      FIG. 11  is an exploded assembly drawing illustrating a filter driving apparatus according to a preferred embodiment of the present invention;  
         [0022]      FIG. 12  is a pictorial drawing illustrating when the filter is not in use for a filter driving apparatus according to a preferred embodiment of the present invention; and  
         [0023]      FIG. 13  is a schematic diagram illustrating when the filter is in use for a filter driving apparatus according to a preferred embodiment of the present invention.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0024]     Referring to  FIG. 1 , a schematic diagram illustrates a filter driving apparatus according to a preferred embodiment of the present invention. A casing  16  of the filter driving apparatus  10  has a main body portion  12  and a cover portion  14 . A fixing block  36  is set on a top of the main body portion  12  for fixing on a camera (as shown in  FIG. 7 ). In addition, a central top area of the filter driving apparatus  10  has a viewing hole  18  of the main body portion  12  and a viewing hole  14   a  of the cover portion  14 . The position of the viewing hole  18  corresponds to the viewing hole  14   a  for passing light beams.  
         [0025]     Referring to  FIG. 2 , a perspective drawing illustrates the main body portion  12  of the filter driving apparatus  10  according to  FIG. 1 . The main body portion  12  has a sliding portion  20 , a filter  22 , a magnetic body  24  and a coil portion  26 . The filter  22  is set on the sliding portion  20 . The sliding portion  20  is connected to the magnetic body  24 . The magnetic body  24  is a rod structure. At least one coil set is placed in the coil portion  26 . An axial of the coil portion  26  parallels an axial of the magnetic body  24 . An opening  26   a  is set at a center of the coil portion  26  for insetting an end of the magnetic body  24 . Different polarities are generated based on different current directions when current passes through the coils, an attractive or a repulsive reaction is then generated between the magnetic body  24  and the coil portion  26 . If an end of the magnetic body  24  is S pole (The end of the magnetic body  24  is near the coil portion  26 ), once current passes through the coil portion  26  and a magnetic field effect of N pole is generated from the coil portion  26 , an attractive force is generated between the magnetic body  24  and the coil portion  26 , or a repulsive force is generated between the magnetic body  24  and the coil portion  26  when current passes through the coil portion  26  and a magnetic field effect of S pole is generated from the coil portion  26 . Alternately, if an end of the magnetic body  24  is N pole (The end of the magnetic body  24  is near the coil portion  26 ), once current passes through the coil portion  26  and a magnetic field effect of N pole is generated from the coil portion  26 , a repulsive force is generated between the magnetic body  24  and the coil portion  26 , or an attractive force is generated between the magnetic body  24  and the coil portion  26  when current passes through the coil portion  26  and a magnetic field effect of S pole is generated from the coil portion  26 .  
         [0026]     Referring to  FIG. 3 , a side elevation view illustrates the filter driving apparatus  10  according to  FIG. 1 . A top and a bottom side within the main body portion  12  have at least one protrusion  28 . A sidewall of the casing  16  has a plurality of baffles  30 . In addition, a top and a bottom side of the sliding portion  20  have ladder structures  32 . The protrusion  28 , the plurality of baffles  30  and the ladder structure  32  are formed channels  38 . The sliding portion  20  can be slid along a presetting path. The protrusion  28  is uniformly distributed along the channels  38  and is for fastening the ladder structures  32 . The plurality of baffles  30  is against the sliding portion  20  to steady the sliding portion  20  on the channels  38  without dropping while the sliding portion  20  is sliding.  
         [0027]     Referring to  FIG. 4 , an exploded diagram illustrates the filter driving apparatus  10  according to  FIG. 1 . The coil portion  26  has an opening  26   a  which corresponds to a central of coils. An end of the magnetic body  24  can be inset into the opening  26   a  of the coil portion  26 . In addition, a central top area of the main body  12  has the viewing hole  18 . The cover portion  14  has the viewing hole  14   a . The position of the viewing hole  18  corresponds to the position of the viewing hole  14   a . The viewing hole  18  overlaps the viewing hole  14   a  when the main body portion  12  is combined with the cover portion  14  as shown in  FIG. 1 .  
         [0028]     Referring to  FIG. 5  to  FIG. 7 ,  FIG. 5  is a pictorial drawing illustrating the filter driving apparatus  10  according to  FIG. 1  when the filter is not in use; and  FIG. 6  is a pictorial drawing illustrating when the filter is in use. As shown in  FIG. 7 , the filter driving apparatus  10  of the present invention is applied for a camera lens  72  of a camera  70 . The camera lens  72  uses a charge coupled device (CCD) or a complementary metal oxide semiconductor (CMOS) chip for the camera lens. The camera  70  can be used day and night. The camera lens  72  corresponds to the viewing hole  18  and the viewing hole  14   a . When a picture is taken during the night, the filter  22  can be withdrawn from the viewing hole  18  as shown in  FIG. 5 . When current passes through the coil portion  26 , the polarity of the magnetic field generated by the magnetic body  26  is then the same as the polarity of the magnetic body  24 . A repulsive force is generated between the coil portion  26  and the magnetic body  24 , the magnetic body  24  is therefore withdrawn from the coil portion  26  as A course. The magnetic body  24  is further taken out from the opening  26   a  of the coil portion  26  as shown in  FIG. 5 . For the filter  22  is set on the sliding portion  20  and the sliding portion  20  is connected to the magnetic body  24 , the sliding portion  20  slides with the magnetic body  24 . The filter  22  can be removed from the viewing hole  18 . In addition, a transparent film  34  without light filtering is further provided for the present invention to increase more convenience in assembling such as a plastic sheet or a glass sheet. The transparent film  34  is covered on the viewing hole  18  as shown in  FIG. 2 . The size of the transparent film  34  is the same as the size of the viewing hole  18 . The transparent film  34  is combined with the viewing hole  18  into a whole.  
         [0029]     When a picture is taken during the day, the daylight is strong. The filter  22  is then needed for filtering the light energy which can not be seen by eyes like ultraviolet or infrared rays. The filter  22  is placed over the viewing hole  18  as shown  FIG. 6 . Current passes through the coil portion  26 , the direction of the current is the reverse of the direction of the current illustrated by  FIG. 5 . An attractive force is then generated between the coil portion  26  and the magnetic body  24 , hence the magnetic body  24  is moved toward the coil portion  26  as B course. The magnetic body  24  is inset into the opening  26   a  of the coil portion  26  as shown in  FIG. 6 . The filter  22  is set on the sliding portion  20 . The sliding portion  20  is connected to the magnetic body  24 . The sliding portion  20  slides with the magnetic body  24 . The filter  22  is placed over and overlapped the viewing hole  18  as shown in  FIG. 6 .  
         [0030]     Referring to  FIG. 10  and  FIG. 11 ,  FIG. 10  is a perspective drawing illustrating the filter driving apparatus according to a preferred embodiment of the present invention and  FIG. 11  is an exploded assembly drawing illustrating the filter driving apparatus. As shown in  FIG. 10 , a main body portion  980  of the filter driving apparatus  98  has a sliding portion  983 , the filter  22 , the magnetic body  24 , a first coil portion  981  and a second coil portion  982 . The filter  22  is set on the sliding portion  983 . The sliding portion  983  is connected to the magnetic body  24 . The magnetic body  24  is a rod structure. As shown in  FIG. 11 , at least one coil set is placed in the first coil portion  981 . An axial of the first coil portion  981  parallels the axial of the magnetic body  24 . An opening  981   a  is set in a center of the first coil portion  981  for insetting the end of the magnetic body  24 . Different polarities are generated based on different current directions when current passes through the coils. An attractive or a repulsive reaction is then generated between the magnetic body  24  and the first coil portion  981 . At least one coil set is placed in the second coil portion  982 . An axial of the second coil portion  982  parallels the axial of the magnetic body  24 . An opening  982   a  is set in a center of the second coil portion  982  for insetting the end of the magnetic body  24 . Different polarities are generated based on different current directions when current passes through the coils, an attractive or a repulsive reaction is then generated between the magnetic body  24  and the second coil portion  982 .  
         [0031]     Referring to  FIG. 12 , a pictorial drawing illustrates when the filter is not in use for the filter driving apparatus. In the filter driving apparatus  98 , if an end of the magnetic body  24  is S pole (The end of the magnetic body  24  is near the first coil portion  981 ) and another end of the magnetic body  24  is N pole (The end of the magnetic body  24  is near the second coil portion  982 ), once current passes through the first coil portion  981  and the second coil portion  982 , a magnetic field effect of N pole is then generated by the first coil portion  981  and the second coil portion  982 . An attractive force is generated between the first coil portion  981  and the magnetic body  24 . A repulsive force is generated between the second coil portion  982  and the magnetic body  24 . Alternately if the end of the magnetic body  24  is N pole (The end of the magnetic body  24  is near the first coil portion  981 ) and another end of the magnetic body  24  is S pole (The end of the magnetic body  24  is near the second coil portion  982 ), when current passes through the first coil portion  981  and the second coil portion  982 , a magnetic field effect of S pole is generated by the first coil portion  981  and the second coil portion  982 . An attractive force is generated between the first coil portion  981  and the magnetic body  24 . A repulsive force is generated between the second coil portion  982  and the magnetic body  24 . By the way mentioned above, the magnetic body  24  is moved toward the first coil portion  981  for insetting the magnetic body  24  into the opening  981   a  (not shown) of the first coil portion  981 . The filter  22  is set on the sliding portion  983 . The sliding portion  983  is connected to the magnetic body  24 . The sliding portion  983  therefore slides with the magnetic body  24 . The filter  22  can be removed from the viewing hole  18 .  
         [0032]     Referring to  FIG. 13 , a schematic diagram illustrates when the filter is in use for the filter driving apparatus. In the filter driving apparatus  98 , if the end of the magnetic body  24  is S pole (The end of the magnetic body  24  is near the first coil portion  981 ) and another end of the magnetic body  24  is N pole (The end of the magnetic body  24  is near the second coil portion  982 ), when current passes through the first coil portion  981  and the second coil portion  982 , a magnetic field effect of S pole is generated by the first coil portion  981  and the second coil portion  982 . A repulsive force is generated between the first coil portion  981  and the magnetic body  24 . An attractive force is generated between the second coil portion  982  and the magnetic body  24 . Alternately if the end of the magnetic body  24  is N pole (The end of the magnetic body  24  is near the first coil portion  981 ) and another end of the magnetic body  24  is S pole (The end of the magnetic body  24  is near the second coil portion  982 ), when current passes through the first coil portion  981  and the second coil portion  982 , a magnetic field effect of N pole is generated by the first coil portion  981  and the second coil portion  982 . A repulsive force is then generated between the first coil portion  981  and the magnetic body  24 . An attractive force is then generated between the second coil portion  982  and the magnetic body  24 . Therefore, the magnetic body  24  is moved toward the second coil portion  982 . The magnetic body  24  can be inset into the opening  982   a  (not shown) of the second coil portion  982 . The filter  22  is set on the sliding portion  983 . The sliding portion  983  is connected to the magnetic body  24 . So the sliding portion  983  slides with the magnetic body  24 . The filter  22  can be placed over or overlapped the viewing hole  18  as shown in  FIG. 13 .  
         [0033]     The filter  22  of the present invention is composed of at least one optical film and can be an Infrared Rays (IR) Cut Filter or an IR Filter. Those filters are usually set at the front of the camera lens  72  for insulating stray light and IR cut. The camera  70  for use day and night, the filter  22  must be used for modification if ambient lights change too fast. The material of the filter  22  can be selected based on demands. The optical low pass filter (OLPF) is combined with the IR cut filter to be the filter while in low-resolution. The OLPF, the IR cut filter and the OLPF are combined to be the filter while in high-resolution.  
         [0034]     Although the features and advantages of the embodiments according to the preferred invention are disclosed, it is not limited to the embodiments described above, but encompasses any and all modifications and changes within the spirit and scope of the following claims.