Abstract:
In a noise removing filter for removing the electromagnetic wave noise leaking from an electronic equipment to the outside via a connector throughhole through which a connector passes, the noise removing filter includes a magnetic member filled in a gap between a body of the electronic equipment and the connector to cover the circumference of the connector.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to an electronic apparatus such as a computer, and more particularly, to a noise removing filter for removing the electromagnetic wave noise leaking from the electronic equipment to the outside.  
           [0003]    2. Description of the Related Art  
           [0004]    Generally, in a computer apparatus, the electromagnetic wave noise leaks from a computer apparatus to the outside via a cable throughhole, and also, conduction noise is generated from a cable.  
           [0005]    In order to suppress the above-mentioned electromagnetic wave noise and the conduction noise, a first prior art noise removing filter is constructed by a ferrite core wound on the cable and a copper foil tape filled in a gap between the ferrite core and the body of the computer apparatus.  
           [0006]    In the above-described first prior art noise removing filter, however, since the manufacturing steps for winding the ferrite core and filling the copper foil tape are necessary, the manufacturing cost is increased.  
           [0007]    A second prior art noise removing filter is constructed by an annular ferrite core having a throughhole through which a cable passes and an annular cover for fixing the annular ferrite core to a body of a computer apparatus (see JP-A-11-214941).  
           [0008]    In the above-described second prior art noise removing filter, however, it is difficult for the inner surface of the annular cover to be adapted to the outer surface of the annular ferrite core, which would increase the manufacturing cost.  
           [0009]    Also, the second prior art noise removing filter cannot be applied to an electronic equipment having a connector throughhole through which a connector passes.  
         SUMMARY OF THE INVENTION  
         [0010]    It is an object of the present invention to provide a noise removing filter capable of decreasing the manufacturing cost.  
           [0011]    According to the present invention, in a noise removing filter for removing the electromagnetic wave noise leaking from an electronic equipment to the outside via a connector throughhole through which a connector passes, the noise removing filter includes a magnetic member filled in a gap between a body of the electronic equipment and the connector to cover the circumference of the connector.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]    The present invention will be more clearly understood from the description set forth below, with reference to the accompanying drawings, wherein:  
         [0013]    [0013]FIGS. 1A and 1B are side views illustrating a first embodiment of the noise removing filter according to the present invention mounted on a computer apparatus;  
         [0014]    [0014]FIG. 2 is a perspective view of the noise removing filter of FIGS. 1A and 1B;  
         [0015]    [0015]FIG. 3 is a perspective view of a modification of the noise removing filter of FIG. 2;  
         [0016]    [0016]FIGS. 4A and 4B are side views illustrating a second embodiment of the noise removing filter according to the present invention mounted on a computer apparatus; and  
         [0017]    [0017]FIGS. 5A an  5 B are side views illustrating a third embodiment of the noise removing filter according to the present invention mounted on a computer apparatus.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]    In FIGS. 1A and 1B, which illustrate a first embodiment of the present invention, reference numeral  1  designates a body of a computer apparatus (not shown) having an inner surface  1   a , an outer surface  1   b  and a connector throughhole  1   c  through which a connector jack  2  fixed to a computer board  3 .  
         [0019]    In FIG. 1A, a noise removing filter  4  is filled in a gap between the body  1  and the connector jack  2  to cover the circumference of the connector jack  2 . In this case, the noise removing filter  5  is mounted on the inner surface of the body  1  by a double-coated tape  4   a , to completely fill the throughhole  1   c.    
         [0020]    Note that the double-coated tape  4   a  of FIGS. 1A and 1B can be replaced by bolts (not shown) inserted through the body  1  and the noise removing filter  4 .  
         [0021]    In FIG. 1B, a user puts a connector plug  5  connected to a cable  6  into the connector jack  5  of FIG. 1A.  
         [0022]    As illustrated in FIG. 2, the noise removing filter  4  of FIGS. 1A and 1B is constructed by a magnetic core section  41  which is filled in the gap between the body  1  and the connector jack  2  and a magnetic core section  42  connected to the magnetic core section  51  mounted on the inner surface of the body  1 . That is, the combination of the magnetic core sections  41  and  42  form a flange member with a rim mounted on the inner surface of the body  1 .  
         [0023]    In FIG. 2, the magnetic core sections  41  and  42  are annular so as to be adapted to the shape of the throughhole  1   c , which is also annular.  
         [0024]    Note that, if the throughhole  1   c  is square or rectangular, the noise removing filter of FIG. 2 is also square or rectangular as illustrated in FIG. 3.  
         [0025]    In FIGS. 4A and 4B, which illustrate a second embodiment of the present invention, the noise removing filter  4 ′, which is the same as the noise removing filter  4  of FIGS. 1A and 1B, is mounted on the outer surface  1   a  of the body  1  by a double-coated tape  4 ′a, to completely fill the throughhole  1   c.    
         [0026]    Note that the double-coated tape  4 ′a of FIGS. 4A and 4B can be also replaced by bolts (not shown) inserted through the body  1  and the noise removing filter  4 .  
         [0027]    In FIG. 4B, a user puts a connector plug  5  connected to a cable  6  into the connector jack  5  of FIG. 4A via the noise removing filter  4 ′.  
         [0028]    In FIGS. 5A and 5B, which illustrate a third embodiment of the present invention, the noise removing filter  5  is mounted on the inner surface  1   a  of the body  1 , and also, the noise removing filter  4 ′ is mounted on the outer surface  1   b  of the body  1 . Even in this case, the noise removing filters  4  and  4 ′ are mounted by double-coated tapes  4   a  and  4 ′a, to completely fill the throughhole  1   c . The combination of the noise removing filters  4  and  4 ′ serve as one noise removing filter.  
         [0029]    Note that the double-coated tape  4 ′a of FIGS. 5A and 5B can be also replaced by bolts (not shown) inserted through the body  1  and the noise removing filter  4 .  
         [0030]    In FIG. 5B, a user puts a connector plug  5  connected to a cable  6  into the connector jack  5  of FIG. 5A via the noise removing filter  4 ′.  
         [0031]    In the above-described embodiments, the noise removing filter can remove the electromagnetic wave noise from the computer apparatus (not shown) as well as the conduction noise generated from the cable  6 .  
         [0032]    Also, the noise removing filter can be made of ferrite.  
         [0033]    As explained hereinabove, according to the present invention, since the adaptation of an annular cover to an annular ferrite core is unnecessary, the manufacturing cost can be reduced.