Abstract:
A connecting apparatus includes equipment having a cabinet with an opening and a connector inside the cabinet. A module has an electrical circuit and a resilient conductor and is attachable to the cabinet through the opening and thereby pluggable to the equipment. When the module is plugged to the equipment, the electrical circuit of the module is connected to the connector of the equipment, the resilient conductor fills a gap in the opening between the module and the cabinet and the module and the cabinet is electrically connected, and static electricity charged on the module propagates through the resilient conductor to the cabinet.

Description:
[0001]    The present application is related to and claims the benefit of foreign priority to Japanese application 2007-133502, filed on May 18, 2007 in the Japan Patent Office, which is incorporated herein by reference in its entirety. 
       BACKGROUND 
     Description of the Related Art 
       [0002]    For a module connecting an optical fiber to an optical communication apparatus, a pluggable module that can be mounted or replaced from a front side of the optical apparatus has widely been used. With an increasing speed of optical communication in recent years, it is demanded to enhance suppression of ESD (Electrostatic Discharge)/EMI (Electro Magnetic Interference) of pluggable modules as well as optical communication apparatus bodies. 
         [0003]    To obtain better suppression of ESD/EMI of pluggable module, a configuration having a member causing static electricity in the module to propagate to a cage for protecting the module is known, such as one disclosed in Japanese Patent Application Laid-Open No. 2006-113455. 
         [0004]      FIG. 11  is a diagram showing a pluggable module according to a related art. As shown in  FIG. 11 , a pluggable module  10  is a module to be connected to an optical connector  50  containing an optical fiber  501 . The pluggable module  10  is inserted into an apparatus  8  through an insertion opening provided in a cabinet  30  of the apparatus  8  before being electrically connected to a circuit board  40  inside the apparatus  8  via a connector  401 . 
         [0005]    A cage  20  is mounted on the circuit board  40  to protect the pluggable module  10 . A spring  201  is provided inside the cage  20  to cause static electricity charged to the outside portion of pluggable module  10  to propagate to the cage  20 . A metallic member  202  is fixed to the cage  20  and the cabinet  30  by spot welding  202   a  and the static electricity propagated to the cage  20  is conducted to the cabinet  30  acting as a ground through the metallic member  202 . 
       SUMMARY 
       [0006]    A connecting apparatus includes: equipment having a cabinet with an opening and a connector inside the cabinet. A module which is attachable to the cabinet through the opening and thereby pluggable to the equipment, has an electrical circuit and a resilient conductor. When the module is plugged to the equipment, the electrical circuit of the module is connected to the connector of the equipment, the resilient conductor fills a gap in the opening between the module and the cabinet, and the module and the cabinet are electrically connected. Static electricity charged on the module propagates through the resilient conductor to the cabinet. 
         [0007]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a diagram showing a pluggable module according to an embodiment; 
           [0009]      FIG. 2  is a perspective view of the pluggable module according to an embodiment; 
           [0010]      FIG. 3  is a diagram showing a pluggable module according to an embodiment; 
           [0011]      FIG. 4  is a diagram showing a pluggable module according to an embodiment; 
           [0012]      FIG. 5  is a diagram showing a pluggable module according to an embodiment; 
           [0013]      FIG. 6  is a diagram showing a pluggable module according to an embodiment; 
           [0014]      FIG. 7  is a diagram showing a pluggable module according to an embodiment; 
           [0015]      FIG. 8  is a diagram showing a pluggable module according to an embodiment; 
           [0016]      FIG. 9  is a diagram showing a pluggable module according to an embodiment; 
           [0017]      FIG. 10  is a diagram showing a pluggable module according to an embodiment; and 
           [0018]      FIG. 11  is a diagram showing a pluggable module according to a related art. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0019]    Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. 
         [0020]    First, a relationship between decreasing a size of a module and the corresponding ESD issue is described. By decreasing a size of a module, a distance between a cabinet of the module and a circuit board inside the module is shortened. 
         [0021]    Accordingly, in the related art shown in  FIG. 11 , for example, even if a structure to allow static electricity charged to the outside portion of the module to escape to a cage is present, there are cases where static electricity discharges to a circuit board and causes malfunctioning, circuit component breakdown and the like. 
         [0022]    Also, a gap present between an insertion opening for inserting a module into an apparatus and the module can act as a path for EMI. Such gap is due to a dimensional tolerance or the like. 
         [0023]    Referring to  FIG. 11 , it is preferable that static electricity  1  is conducted from outside the apparatus  8  to the cabinet  30  by passing through a discharge route  2 , from the pluggable module  10 , through the spring  201 , the cage  20 , and the metallic member  202 , to the cabinet  30 . 
         [0024]    However, since a distance d 1  between the spring  201  and a circuit board  101 , which controls optical elements inside the pluggable module  10 , is short, there are cases where static electricity discharges to the circuit board  101  and causes a malfunction, circuit component breakdown and the like. This problem becomes more serious with further decrease in the size of the pluggable module  10  due to communication speedups or composition with higher densities. 
         [0025]    Also in  FIG. 11 , since there arises a gap between the insertion opening provided in the cabinet  30  and the pluggable module  10  due to a dimensional tolerance or the like, there is another problem that EMI  3  emitted from the pluggable module  10  or the connector  401  or EMI (not shown) generated inside the apparatus, leaks out as EMI  4 . 
         [0026]      FIG. 1  is a diagram showing a pluggable module  11   a  according to an embodiment. As shown in  FIG. 1 , the pluggable module  11   a  includes a shield spring  112   a.  The shield spring  112   a  fills a gap between an insertion opening provided in the cabinet  30  and the pluggable module  11   a.  The pluggable module  11   a  comes into contact with the cabinet  30  by the shield spring  112   a  due to elastic force, after being inserted into an apparatus  8 . The shield spring  112   a  can be a resilient conductor that can isolate the module outside the cabinet and the inside the cabinet, made of a conductive material, for example, metal, metalized resin, or the like. 
         [0027]    Static electricity  1  conducted to the pluggable module  11   a  from outside the apparatus  8 , propagates through the discharge route  2   a  from the pluggable module  11   a  to the shield spring  112   a  and the cabinet  30 . Thus, it is not necessary to provide a spring  201  for the cage  21  or the metallic member  202  in order to protect the pluggable module  11   a.    
         [0028]    In this configuration, since the shield spring  112   a  in the pluggable module  11   a  is directly in contact with the cabinet  30  of the apparatus  8 , the static electricity reaches the cabinet  30  through the discharge route  2   a  without coming close to the circuit board  101 . This makes it easier to protect the circuit board  101  inside the pluggable module  11   a.    
         [0029]    Also in this configuration, as the gap between the insertion opening provided in the cabinet  30  and the pluggable module  11   a  is filled by the shield spring  112   a,  it is possible to inhibit leakage of the EMI  3  or the like emitted from the pluggable module  11   a  or the connector  401  through the gap. 
         [0030]      FIG. 2  is a perspective view of the pluggable module  11   a.  As shown in  FIG. 2 , the pluggable module  11   a  includes a plurality of shield springs  112   a  on a top surface, both sides, and an undersurface thereof. In order to inhibit leakage of EMI, a gap g between each of the shield springs  112   a  is preferably not higher than ⅕ of a wavelength X of EMI. 
         [0031]    Referring to  FIG. 3 , a pluggable module  11   b  has a structure in which a shield spring  112   b  is in contact with the cabinet  30  not only inside the apparatus  8 , but also outside the apparatus  8 . By this configuration, a discharge route  2   b  is remote from the circuit board  101 , and the circuit board  101  is less likely to be affected by static electricity. 
         [0032]    Referring to  FIG. 4 , a pluggable module  11   c  has a structure in which a portion where a shield spring  112   c  is in contact with the cabinet  30  outside the apparatus is apart from the center of the pluggable module  11   a.  Therefore, a discharge route  2   c  is made further remote from the circuit board  101  and the circuit board  101  is less likely to be affected by static electricity. 
         [0033]    Referring to  FIG. 5 , a pluggable module lid has two bending portions of the shield spring  112   d  extending in the same direction, different from the pluggable module  11   b  shown in  FIG. 3  and the pluggable module  11   c  shown in  FIG. 4 . That is, a bending portion that brings the shield spring  112   d  into contact with the cabinet  30  outside the apparatus  8  and a bending portion that is exposed to the outside of the apparatus  8  extends the same direction. Therefore, while having an effect similar to that of the pluggable module  11   b  shown in  FIG. 3  or the pluggable module  11   c  shown in  FIG. 4 , the pluggable module lid in  FIG. 5  has a structure that is easier to work on than that of these pluggable modules. 
         [0034]    Referring to  FIG. 6 , a pluggable module  11   e  has a structure in which a shield spring  112   e  is in contact with the cabinet  30  outside the apparatus with a structure similar to the shield spring  112   b  of the pluggable module  112   b  in  FIG. 3 . Additionally, the shield spring  112   e  is not in contact with the cabinet  30  inside the apparatus, but is in contact with the cage  21 . Accordingly, the pluggable module  11   e  has a structure that inhibits leakage of EMI from inside the cage. 
         [0035]    Referring to  FIG. 7 , a pluggable module  11   f  has a structure in which a shield spring  112   f  is in contact with the cabinet  30  outside the apparatus with a structure similar to the shield spring  112   c  of the pluggable module  112   c  in  FIG. 4 . Additionally, the shield spring  112   f  is not in contact with the cabinet  30  inside the apparatus, but is in contact with the cage  21 . Accordingly, the pluggable module  11   f  has a structure that inhibits leakage of EMI from inside the cage. 
         [0036]    Referring to  FIG. 8 , a pluggable module  11   g  has a structure in which a shield spring  112   g  is in contact with the cabinet  30  outside the apparatus with a structure similar to the shield spring  112   d  of the pluggable module  112   d  in  FIG. 5 . Additionally, the shield spring  112   g  is not in contact with the cabinet  30  inside the apparatus, but is in contact with the cage  21 . Accordingly, the pluggable module  11   g  has a structure that inhibits leakage of EMI from inside the cage. 
         [0037]    Referring to  FIG. 9 , a pluggable module  11   h  has a structure in which a shield spring  112   h  is in contact with the cabinet  30  outside the apparatus. Additionally, the shield spring  112   h  is not in contact with the cabinet  30  inside the apparatus, but is in contact with the cage  21 . Thus, the pluggable module  11   h  has a structure that inhibits leakage of EMI from inside the cage. 
         [0038]    As described above, in the embodiments shown in  FIGS. 1 to 9 , a shield spring is provided near a gap between a pluggable module and a cabinet of an apparatus to allow static electricity charged to the outside portion of the pluggable module to escape to the cabinet of the apparatus and also to fill the gap between the pluggable module and the cabinet of the apparatus by the shield spring. Therefore, suppression of ESD/EMI of the pluggable module is increased. 
         [0039]    In the above embodiments, examples of suppressing ESD/EMI of a pluggable module by using a shield spring are shown, but suppression of ESD/EMI can also be enhanced by using members other than the shield spring. 
         [0040]    Referring to  FIG. 10 , in a pluggable module  11   i  a conductive resin is used in combination to enhance suppression of ESD/EMI of the pluggable module  11   i.    
         [0041]    As shown in  FIG. 10 , the pluggable module  11   i  includes a conductive resin  112   i  in addition to the shield spring  112   a  shown in  FIG. 1 . When the pluggable module  11   i  is inserted into the insertion opening of the cabinet  30 , the conductive resin  112   i  comes into contact with the cabinet  30  and also a space between the pluggable module  11   i  and the cabinet  30  is filled. The conductive resin  112   i  is, for example, a rubber with metallic filler or conductive fiber around a circumference thereof and preferably has elasticity. 
         [0042]    Since the conductive resin  112   i  provided by the pluggable module  11   i  is directly in contact with the cabinet  30  of the apparatus in this configuration, static electricity reaches the cabinet  30  without coming close to the circuit board  101  on the discharge route  2   i.  This makes protection of the circuit board  101  inside the pluggable module  11   i  easier. 
         [0043]    Also in this configuration, the space between the cabinet  30  and the pluggable module  11   i  is filled by the conductive resin  112   i.  Therefore, the EMI  3  and the like emitted from the pluggable module  11   i  and the connector  401  can be inhibited from leaking out through the gap between the cabinet  30  and the pluggable module  11   i.  By using a conductive resin in combination, as described above, better suppression of ESD/EMI of the pluggable module. 
         [0044]    As described above, a conductive member is provided in a pluggable module to allow static electricity charged to the outside portion of the pluggable module to escape to a cabinet of an apparatus by way of the conductive member and also to fill a gap between the pluggable module and the cabinet of the apparatus to inhibit leakage of EMI. Therefore, better suppression of ESD/EMI of the pluggable module is provided with a simple structure. 
         [0045]    Although a few preferred embodiments of the present invention have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the claim and their equivalents.