Abstract:
A connection device, capable of visually confirming the connection between a connector pair, including: an optical connector pair that includes a first optical connector and a second optical connector each of which includes a plurality of terminals and corresponding terminals of which are connected to each other by light; a guide light member that guides light to a terminal of one of the first optical connector and the second optical connector; and a visual recognition member that is used to visually recognize the light that passes through from the terminal of the selected optical connector to a terminal of the opposite optical connector.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority of the prior Japanese Patent Application No. 2014-068610, filed on Mar. 28, 2014, the entire contents of which are incorporated herein by reference. 
       FIELD 
       [0002]    The embodiments discussed herein are related to a connection device, a computer system, and a connection method of the computer system. 
       BACKGROUND 
       [0003]    There is a device in which a light source having different hues or emission patterns that respectively correspond to a plurality of optical fibers is provided on the back surface of an insertion port into which a connector at one end of an optical fiber is inserted, and the connection is checked by observing the light state from a connector at the other end of the optical cable. 
         [0004]    In addition, there is a method in which a light emitter that emits visible light is caused to face the cross-section at one end of an optical fiber cable that includes one or more optical fiber core wires from among the cross-sections of both ends of the optical fiber cable, and the visible light is caused to pass through the whole optical fiber core wires to check the presence or absence of an optical fiber core wire that does not emit light by visual check of the cross-section of the other end of the optical fiber cable. 
         [0005]    Japanese Registered Utility Model No. 3166071, and Japanese Laid-open Patent Publication No. 5-180728 are the related arts. 
         [0006]    There is a case in which it is difficult to check the connection state between optical connectors that are connected to each other through light. 
         [0007]    An object of the technology discussed herein is to easily check the connection state between optical connectors. 
       SUMMARY 
       [0008]    According to an aspect of the invention, a connection device, capable of visually confirming the connection between a connector pair, is disclosed, which includes: an optical connector pair that includes a first optical connector and a second optical connector each of which includes a plurality of terminals and corresponding terminals of which are connected to each other by light; a guide light member that guides light to a terminal of one of the first optical connector and the second optical connector; and a visual recognition member that is used to visually recognize the light that passes through from the terminal of the selected optical connector to a terminal of the opposite optical connector. 
         [0009]    The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
         [0010]    It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0011]      FIG. 1  is a perspective view illustrating a computer system according to a first embodiment; 
           [0012]      FIG. 2  is a perspective view illustrating a computer unit and a line arrangement device according to the first embodiment; 
           [0013]      FIG. 3  is a plan view illustrating the computer unit and the line arrangement device according to line arrangement device the first embodiment; 
           [0014]      FIG. 4  is a plan view partially magnifying a connection device according to the first embodiment; 
           [0015]      FIG. 5  is a plan view partially magnifying a connection device according to a second embodiment; 
           [0016]      FIG. 6  is a plan view partially magnifying a connection device according to a third embodiment; 
           [0017]      FIG. 7  is a plan view partially magnifying a connection device according to a fourth embodiment; 
           [0018]      FIG. 8  is a plan view partially magnifying a connection device according to a fifth embodiment; 
           [0019]      FIG. 9  is a plan view partially magnifying a connection device according to a sixth embodiment; 
           [0020]      FIG. 10  is a plan view partially magnifying a connection device according to a seventh embodiment; 
           [0021]      FIG. 11  is a plan view partially magnifying a connection device according to an eighth embodiment; and 
           [0022]      FIG. 12  is a plan view partially magnifying a connection device according to a ninth embodiment. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
       [0023]    A first embodiment is described below in detail with reference to drawings. 
         [0024]    In  FIG. 1 , a parallel computer system (hereinafter, simply referred to as computer system)  12  according to the first embodiment is illustrated. The computer system  12  includes a plurality of computer units  14 . In the example illustrated in  FIG. 1 , the plurality of computer units  14  are arranged in a three dimension, that is, in the X direction, the Y direction, and the Z direction that are orthogonal to each other. In addition, the plurality of computer units  14  is connected to each other in a loop through an optical cable  18  in the respective X direction, Y direction, and Z direction. As a result, in the entire computer system  12 , the computer units  14  are directly connected to each other through the optical cable  18 , or connected to each other through the optical cable  18  and a further computer unit  14 . The number of the computer units  14  that are arranged in the X direction, the Y direction, and the Z direction is not particularly limited. 
         [0025]    In  FIGS. 2 and 3 , the computer unit  14  and a line arrangement device  16  according to the first embodiment are illustrated. In a housing  20  of the computer unit  14 , a single or a plurality of (two in  FIG. 3 ) substrates  22  are arranged. Each of the substrates  22  is inserted into and removed from the housing  20  through the opening on one end  20 A side of the substrate  22 . The direction in which the substrate  22  is inserted into the housing  20  is illustrated by the arrow A 1  in  FIGS. 2 and 3 . 
         [0026]    The substrate  22  and the line arrangement device  16  are connected to each other through a connection device  58  by light. As described later, the connection device  58  includes optical connector pairs  24  (first optical connectors  26  and second optical connectors  28 ), first optical fibers  46 , and second optical fibers  48 . 
         [0027]    On the other end  22 B of the substrate  22 , the first optical connectors  26  are installed. In the example of  FIG. 3 , the six first optical connectors  26  are arranged on the single substrate  22  along the other end  22 B of the substrate  22  in total. 
         [0028]    On the substrate  22 , an arithmetic processing device  30  is installed. In the arithmetic processing device  30  of the example illustrated in  FIG. 3 , information is transmitted and received between a central processing unit (CPU)  32  and a relay module  34  using an electrical signal. Between the relay module  34  side (electrical signal) and the first optical connector  26  side (optical signal), photoelectric conversion is performed on a signal by a photoelectric conversion module  36 . The photoelectric conversion module  36  and the first optical connector  26  are connected to each other through a communication optical cable  42 . 
         [0029]    On the other end  20 B side of the housing  20 , the line arrangement device  16  is arranged. The line arrangement device  16  according to the first embodiment includes a line arrangement box  38 . 
         [0030]    As illustrated in  FIGS. 3 and 4 , on one end  38 A side of the line arrangement box  38 , the second optical connectors  28  are provided that are respectively connected to the first optical connectors  26  by one-to-one. In the example of  FIGS. 3 and 4 , the single line arrangement device  16  is provided for the two substrates  22 , so that the 12 second optical connectors  28  are provided for the single line arrangement box  38 . 
         [0031]    On the other end  38 B side of the line arrangement box  38  of the line arrangement device  16 , external connectors  40  are provided. The six external connectors  40  are provided for the single line arrangement device  16  so as to correspond to the plus (+) and minus (−) of the X direction, the Y direction, and the Z direction. 
         [0032]    In the line arrangement device  16 , the second optical connectors  28  and the external connectors  40  are connected to each other through a plurality of communication optical cables  44  by light. Using the communication optical cables  44 , rearrangement (line arrangement) is performed between the second optical connectors  28  and the external connectors  40  so that the external connectors  40  correspond to the plus (+) and minus (−) of the X direction, the Y direction, and the Z direction. 
         [0033]    A light source  50  is installed on each of the substrates  22 . In the example illustrated in  FIGS. 3 and 4 , the single light source  50  is installed for the single substrate  22 . The light source  50  is connected to each of the first optical connectors  26  through the first optical fiber  46 . The first optical fiber  46  guides light from the light source  50  to a terminal (pin) in the first optical connector  26 , which is not used to transmit and receive an optical signal to and from the second optical connector  28 . The first optical fiber  46  is an example of a guide light member. 
         [0034]    The line arrangement device  16  includes a visual recognition member  56 . In the example illustrated in  FIGS. 3 and 4 , the visual recognition member  56  includes the second optical fiber  48  and a window member  52 . 
         [0035]    The window member  52  is provided on the other end  38 B side of the line arrangement box  38  of the line arrangement device  16 . The window members  52  respectively correspond to the second optical connectors  28  by one-to-one. The second optical connectors  28  are respectively connected to the window members  52  through the second optical fibers  48 . The second optical fiber  48  guides light to the window member  52  from a terminal (pin) in the second optical connector  28 , which is not used to transmit and receive an optical signal to and from the first optical connector  26 . 
         [0036]    The window member  52  is, for example, a tubular member inside which light is allowed to pass through. The window member  52  includes a visual check section  54  on the other side to the connection side of the second optical connector  28 . 
         [0037]    When the light source  50  emits light in a state in which the first optical connector  26  and the second optical connector  28  are connected to each other correctly, the light reaches the window member  52  through the first optical fiber  46 , the first optical connector  26 , the second optical connector  28 , and the second optical fiber  48 . That is, it may be checked whether or not the first optical connector  26  and the second optical connector  28  are connected to each other correctly by viewing the window member  52  from the visual check section  54  side and checking whether or not the light from the light source  50  has arrived. 
         [0038]    A lens, a diffuser panel, or the like, which is used to guide light to the visual check section  54 , may be provide in the window member  52  to improve the visibility. 
         [0039]    In the first embodiment, the first optical connector  26  is “one of optical connectors”, and the second optical connector  28  is “the other optical connector”. In addition, the substrate  22  is an example of a first mounting member. 
         [0040]    An operation of the embodiment is described below. 
         [0041]    As illustrated by the arrow A 1  in  FIGS. 2 and 3 , the substrate  22  is inserted into the housing  20  through the opening on the one end  20 A side of the housing  20 , and the first optical connector  26  of the substrate  22  is connected to the second optical connector  28  of the line arrangement device  16 . In addition, when the light source  50  is caused to emit light, the light from the light source  50  is guided to a terminal of the first optical connector  26  (terminal that is not used to transmit and receive an optical signal to and from the second optical connector  28 ) through the first optical fiber  46 . 
         [0042]    Here, as illustrated in  FIG. 4 , when the first optical connector  26  and the second optical connector  28  are securely connected to each other, light from the light source  50  passes through from a terminal of the first optical connector  26  to a terminal of the second optical connector  28 . In addition, the light reaches the window member  52  through the second optical fiber  48  from the terminal of the second optical connector  28 . Thus, it may be determined that the first optical connector  26  and the second optical connector  28  are securely connected to each other when the light is visually recognized by visual check of the visual check section  54 . 
         [0043]    On the contrary, when the light is not visually recognized after the visual check section  54  has been visually checked (or when the light is weaker than expected), it may be determined that the first optical connector  26  and the second optical connector  28  are not securely connected to each other. In this case, for example, it is sufficient to perform re-connection between the first optical connector  26  and the second optical connector  28  by inserting the substrate  22  into the housing  20  again, or the like. 
         [0044]    After check of the connection state between the first optical connector  26  and the second optical connector  28  has been completed, light-emission of the light source  50  is terminated. 
         [0045]    As described above, in the first embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be checked by visual recognition of the visual check section  54  of the window member  52 . In particular, the first optical connector  26  is located away from the one end  20 A side of the housing  20  in the state in which the first optical connector  26  and the second optical connector  28  are connected to each other, so that it is difficult to visually check the connection state from the one end  20 A side of the housing  20 . 
         [0046]    When the connection between the first optical connector  26  and the second optical connector  28  is incomplete, the first optical connector  26  may be located on the left side of  FIG. 3  as compared with the normal connection state. For example, when the insertion length of the substrate  22  in the arrow A 1  direction is insufficient, the connection between the first optical connector  26  and the second optical connector  28  becomes incomplete. Therefore, by inserting a rod or the like from the one end  20 A side of the housing  20 , the position of the first optical connector  26  may be determined from the insertion length when the rod is in contact with the first optical connector  26 . In addition, the connection state between the first optical connector  26  and the second optical connector  28  may be checked by determining the position of the first optical connector  26 . However, it may be difficult to perform such an operation because the rod is inserted into the housing  20  and is caused to contact the first optical connector  26 . On the contrary, in the embodiment, the visual check section  54  of the window member  52  is visually checked, so that the connection state between the first optical connector  26  and the second optical connector  28  is checked easily. 
         [0047]    In addition, a method is also conceivable in which a sensor is provided in order to check the connection state between the first optical connector  26  and the second optical connector  28 . However, when the sensor is provided, an increase in the cost may be caused due to the provision of the sensor and a cable that is used to transmit and receive an electrical signal to and from the sensor. In the embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be checked using redundant pins of the first optical connector  26  and the second optical connector  28  without such a sensor, thereby suppressing the increase in the cost. 
         [0048]    In the first embodiment, the single light source  50  is shared between the plurality of (six in the example illustrated in  FIG. 1 ) first optical connectors  26 , so that, for example, a reduction in the cost and weight may be achieved as compared with a structure in which a light source is provided in each of the first optical connectors  26 . Even in a structure in which a plurality of first optical connectors  26  is grouped, and a single light source is provided for each of the groups, a reduction in the cost and weight may be achieved as compared with the structure in which the light source is provided for each of the first optical connectors  26 . 
         [0049]    Light from the light source  50  is guided to the first optical connector  26  through the first optical fiber  46 . In such a structure, the light may be guided to the first optical connector  26  while the diffusion of light is suppressed as compared with a structure in which the first optical fiber  46  is not included, for example, a structure in which light from the light source  50  is directly emitted to the first optical connector  26 . In addition, the light from the light source  50  is guided to the first optical connector  26  through the first optical fiber  46 , so that the light source  50  may be located away from the first optical connector  26 . In addition, even when a further member is located between the light source  50  and the first optical connector  26 , the light from the light source  50  may be guided to the first optical connector  26 . Therefore, the degree of freedom is high for the design of the substrate  22  and the arrangement of the members. 
         [0050]    The same number of the first optical fibers  46  as the plurality of first optical connectors  26  is provided, and the first optical connectors  26  respectively correspond to the first optical fibers  46  by one-to-one. Thus, light may be reliably guided from the light source  50  to each of the first optical connectors  26 . 
         [0051]    In the first embodiment, the first optical connectors  26  and the light source  50  are installed on the substrate  22 . The substrate  22  is an example of a first mounting member. That is, the first optical connectors  26  and the light source  50  are integrated so as to be installed on the first mounting member, so that, for example, handling of such a structure becomes easy as compared with a structure in which the light source  50  is provided separately from the substrate  22 . 
         [0052]    In the first embodiment, the visual recognition member includes the window member  52  and the second optical fiber  48 , and light is reliably guided to the window member  52  from the second optical connector  28 . In addition, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visual check of the visual check section  54  of the window member  52 . 
         [0053]    In particular, the single line arrangement device  16  includes the plurality of ( 12  in the example illustrated in  FIGS. 3 and 4 ) second optical connectors  28 , and the window members  52  the number of which is same as the number of second optical connectors  28  are provided. In addition, each of the second optical fibers  48  guides light from the second optical connector  28  to the window member  52 . The plurality of second optical connectors  28  respectively corresponds to the window members  52  by one-to-one, so that the connection state of each of the plurality of optical connector pairs  24  may be checked individually. 
         [0054]    A connection device  62  according to the second embodiment is described below. In the second to sixth embodiments that are descried later, the entire structure of the computer system  12  is similar to that of the first embodiment, so that the description is omitted herein. In addition, in the second embodiment, the same symbol is assigned to an element, a member, or the like that is similar to that of the first embodiment, and the detailed description is omitted. 
         [0055]    In the below description, for convenience of description, combinations of the plurality of first optical connectors  26  and the corresponding second optical connectors  28  the number of which is same as the first optical connectors  26  in the single substrate  22  are regarded as a connector group  64 . In the example illustrated in  FIG. 5 , there are two substrates  22 , so that the number of connector groups  64  is also two. In addition, the single connector group  64  includes six optical connector pairs  24 . 
         [0056]    In the substrate  22  according to the second embodiment, in the connector group  64 , the first optical fiber  46  guides light from the light source  50  to the first optical connector  26 A at one end in the arrangement direction from among the plurality of first optical connectors  26 . 
         [0057]    In addition, in the second embodiment, in the line arrangement device  16 , the window members  52  the number of which is the same as the number of connector groups  64  are provided. In addition, in each of the connector groups  64 , the second optical fiber  48  guides light between the window member  52  and the second optical connector  28 F at the other end in the arrangement direction from among the plurality of second optical connectors  28 . 
         [0058]    In the connector group  64 , between the first optical connector  26 A at the one end in the arrangement direction and the second optical connector  28 F at the other end in the arrangement direction, the optical connector pairs  24  are connected to each other through optical fibers  66  to form a light guide  68 . When light that passes through the light guide  68  is regarded as a reference, the first optical connector  26 A is the beginning end, and the second optical connector  28 F is the terminal end. 
         [0059]    In the second embodiment, when the light source  50  emits light in the state in which the first optical connector  26  and the second optical connector  28  are securely connected to each other, the light enters the first optical connector  26 A from the first optical fiber  46 , and passes through the light guide  68 . That is, the light passes through the respective optical connector pairs  24  in turn. In addition, the light reaches the window member  52  through from the second optical connector  28 F to the second optical fiber  48 . That is, in the second embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily recognized by visually recognizing the visual check section  54  of the window member  52 . 
         [0060]    In the second embodiment, the light guide  68  is formed, and light is guided from the first optical connector  26 A to the second optical connector  28 F through the light guide  68 , so that it is only sufficient to provide the single second optical fiber  48  and the single window member  52  for a single connector group. Therefore, simplification of the structure, and a reduction in the weight and cost of the structure may be achieved in the line arrangement device  16 . 
         [0061]    The first optical fiber  46  is connected to the first optical connector  26 A that is located at the beginning end in the arrangement direction of the first optical connectors  26 , in the connector group  64 . The second optical fiber  48  is connected to the second optical connector  28 F that is located at the terminal end in the arrangement direction of the second optical connectors  28 , in the connector group  64 . In addition, the light guide  68  that passes through the respective optical connector pairs  24  is formed between the first optical connector  26 A at the beginning end and the second optical connector  28 F at the terminal end. Therefore, the light may be guided to all of the first optical connectors  26  and the second optical connectors  28  in the connector group  64 . 
         [0062]    In the second embodiment, it is said that the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector”. However, there is also a connector pair in which light passes through from the second optical connector  28  to the first optical connector  26 . In such a connector pair, it is also said that the second optical connector  28  is an example of “one of optical connectors”, and the first optical connector  26  is an example of “the other optical connector”. In addition, the substrate  22  is an example of “first mounting member”. 
         [0063]    A connection device  72  according to a third embodiment is described below. In the third embodiment, the same symbol is assigned to an element, a member, or the like that is similar to that of the first embodiment or the second embodiment, and the detailed description is omitted herein. 
         [0064]    In the third embodiment, as illustrated in  FIG. 6 , a light reception member  74  is provided in the line arrangement device  16 . In the example illustrated in  FIG. 6 , the light reception member  74  is installed on the other end  38 B side of the line arrangement box  38 . In addition, the first optical fiber  46  is provided between the light reception member  74  and the second optical connector  28 A on the one end side of the connector group  64 . 
         [0065]    In the third embodiment, a light source  76  is used that is provided separately from the substrate  22  and the line arrangement device  16 . When light from the light source  76  is emitted to the light reception member  74 , the light enters the second optical connector  28 A through the first optical fiber  46 , passes through the light guides  68  and  66 , and reaches the window member  52  through from the second optical connector  28 F to the second optical fiber  48 . That is, in the third embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0066]    In the third embodiment, light is guided from the second optical connector  28 A to the second optical connector  28 F through the light guide  68 , so that it is only sufficient to provide the single second optical fiber  48  and the single window member  52  for the single connector group. Therefore, simplification of the structure and a reduction in the weight and cost of the structure may be achieved in the line arrangement device  16 . 
         [0067]    The first optical fiber  46  is connected to the second optical connector  28 A that is located at the beginning end in the connector group  64 . The second optical fiber  48  is connected to the second optical connector  28 F that is located at the terminal end in the connector group  64 . Therefore, light may be guided through all of the first optical connectors  26  and the second optical connectors  28  in the connector group  64 . 
         [0068]    In the third embodiment, the light source  76  is provided separately from the substrate  22  and the line arrangement device  16 . Therefore, a reduction in the weight and cost of the substrate  22  and the line arrangement device  16  may be achieved. The light source  76  may be shared with a further connection device  72 . 
         [0069]    In the third embodiment, as illustrated in  FIG. 6 , both of the light reception member  74  and the window member  52  are arranged on the other end  38 B side of the line arrangement box  38 . A work position in which the light reception member  74  is lighted by the light source  50  is close to a work position in which the window member  52  is visually recognized, so that the connection state between the first optical connector  26  and the second optical connector  28  is easily checked. 
         [0070]    In the third embodiment, it is said that the second optical connector  28  is an example of “one of optical connectors”, and the first optical connector  26  is an example of “the other optical connector”. However, there may be also a connector pair in which light passes through from the first optical connector  26  to the second optical connector  28 . In such a connector pair, it is also said that the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector”. In addition, the line arrangement box  38  is an example “second mounting member”. 
         [0071]    A connection device  82  according to a fourth embodiment is described below. In the fourth embodiment, the same symbol is assigned to an element, a member, or the like that is similar to that of the first, second, or third embodiment, and the detailed description is omitted herein. 
         [0072]    In the fourth embodiment, as illustrated in  FIG. 7 , the light source  50  and the first optical fiber  46  are provided in the substrate  22 . The first optical fiber  46  is connected to the first optical connector  26 A on the one end side of the connector group  64 . The second optical fiber  48  may be provided between the window member  52  and the second optical connector  28 F on the other end side of the connector group  64 . 
         [0073]    In addition, in the fourth embodiment, through optical fibers  84 , the second optical connector  28 A and the second optical connector  28 B are connected each other, and the second optical connector  28 C and the second optical connector  28 D are connected to each other, and the second optical connector  28 E and the second optical connector  28 F are connected to each other. In addition, through the optical fibers  84 , the first optical connector  26 B and the first optical connector  26 C are connected to each other, and the first optical connector  26 D and the first optical connector  26 E are connected to each other. In addition, an optical fiber  84 F is provided that emits light from a terminal that is different from a terminal to which light enters, in the first optical connector  26 F. 
         [0074]    In the fourth embodiment, light from the light source  50  enters the first optical connector  26 A through the first optical fiber  46 , passes through the light guide  68 , and reaches the window member  52  through from the second optical connector  28 F to the second optical fiber  48 . That is, in the fourth embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0075]    In the fourth embodiment, the number of optical fibers  84  in the single connector group  64  is small as compared with the second embodiment and the third embodiment, so that a reduction in the weight and cost may be achieved. 
         [0076]    In the fourth embodiment, a connector pair in which the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector”, and a connector pair having the inverse positional relationship to such a connector pair are arranged alternately. In addition, the substrate  22  is an example of “first mounting member”. 
         [0077]    A connection device  102  according to a fifth embodiment is described below. In the fifth embodiment, the same symbol is assigned to an element, a member, or the like that is similar to that of the first, second, third, or fourth embodiment, and the detailed description is omitted herein. 
         [0078]    In the fifth embodiment, as illustrated in  FIG. 8 , the light reception member  74  is provided in the line arrangement device  16 . In the example illustrated in  FIG. 8 , the light reception member  74  is installed on the other end  38 B side of the line arrangement box  38 . In addition, the first optical fiber  46  is provided between the light reception member  74  and the second optical connector  28 A on the beginning end side of the connector group  64 . 
         [0079]    In the fifth embodiment, through the optical fibers  84 , the first optical connector  26 A and the first optical connector  26 B are connected to each other, and the first optical connector  26 C and the first optical connector  26 D are connected to each other, and the first optical connector  26 E and the first optical connector  26 F are connected to each other. In addition, through the optical fibers  84 , the second optical connector  28 B and the second optical connector  28 C are connected to each other, and the second optical connector  28 D and the second optical connector  28 E are connected to each other. 
         [0080]    In the fifth embodiment, the light source  76  is used that is provided separately from the substrate  22  and the line arrangement device  16 . When light from the light source  76  is emitted to the light reception member  74 , the light enters the second optical connector  28 A through the first optical fiber  46 , passes through the light guide  68 , and reaches the window member  52  through from the second optical connector  28 F to the second optical fiber  48 . That is, in the fifth embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0081]    In the fifth embodiment, the number of optical fibers  84  in the single connector group  64  is small as compared with the second embodiment and the third embodiment, so that a reduction in the weight and cost may be achieved. 
         [0082]    In addition, in the fifth embodiment, the light source  76  is provided separately from the substrate  22  and the line arrangement device  16 . Therefore, a reduction in the weight and cost of the substrate  22  and the line arrangement device  16  may be achieved. The light source  76  may be shared with a further connection device  72 . 
         [0083]    In the fifth embodiment, a connector pair in which the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector”, and a connector pair having the inverse positional relationship to such a connector pair are arranged alternately. In addition, the line arrangement box  38  is an example of “second mounting member”. 
         [0084]    A connection device  112  according to a sixth embodiment is described below. In the sixth embodiment, the same symbol is assigned to an element, a member, or the like that is similar to that of the first, second, third, fourth, or fifth embodiment, and the detailed description is omitted herein. 
         [0085]    In the sixth embodiment, as illustrated in  FIG. 9 , the light source  50  is provided in the line arrangement device  16 . In the example illustrated in  FIG. 9 , the light sources  50  are provided so as to respectively correspond to the connector groups  64 . In addition, the first optical fiber  46  is provided between the light source  50  and each of the second optical connectors  28  in the connector group  64 . 
         [0086]    In addition, in the sixth embodiment, in each of the first optical connectors  26 , the optical fiber  84 F is provided that emits light from a terminal that is different from a terminal to which light enters. 
         [0087]    In the sixth embodiment, light from the light source  50  enters the second optical connector  28  through the first optical fiber  46 . When the first optical connector  26  and the second optical connector  28  are securely connected to each other, the light enters the first optical connector  26 . In addition, the light that has been emitted from the first optical connector  26  returns to the first optical connector  26  through the optical fiber  84 F. The light reaches the window member  52  through from the second optical connector  28  to the second optical fiber  48 . That is, in the sixth embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0088]    In the sixth embodiment, it is said that the second optical connector  28  is an example of “one of optical connectors”, and the first optical connector  26  is an example of “the other optical connector”. However, light also passes through from the first optical connector  26  to the second optical connector  28 , and it may be also said that the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector”. In addition, the line arrangement box  38  is an example of “second mounting member”. 
         [0089]    A connection device  122  according to a seventh embodiment is described below. In the seventh embodiment, the same symbol is assigned to an element, a member, or the like that is similar to that of the first, second, third, fourth, fifth, or sixth embodiment, and the detailed description is omitted herein. 
         [0090]    In the seventh embodiment, as illustrated in  FIG. 10 , the light reception member  74  is provided in the line arrangement device  16 . In the example illustrated in  FIG. 10 , the light reception member  74  is installed on the other end  38 B side of the line arrangement box  38 . In addition, the first optical fiber  46  is provided between the light reception member  74  and each of the second optical connectors  28  in the connector group  64 . 
         [0091]    In addition, in the seventh embodiment, in each of the first optical connectors  26 , the optical fiber  84 F is provided that emits light from a terminal that is different from a terminal that light enters. 
         [0092]    In the seventh embodiment, when light from the light source  76  is emitted to the light reception member  74 , the light enters the second optical connector  28  through the first optical fiber  46 . When the first optical connector  26  and the second optical connector  28  are securely connected to each other, the light enters the first optical connector  26 . In addition, the light that has been emitted from the first optical connector  26  is returned to the first optical connector  26  through the optical fiber  84 F. The light reaches the window member  52  through from the second optical connector  28  to the second optical fiber  48 . That is, in the sixth embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0093]    In addition, in the seventh embodiment, the light source  76  is provided separately from the substrate  22  and the line arrangement device  16 . Therefore, a reduction in the weight and cost of the substrate  22  and the line arrangement device  16  may be achieved. The light source  76  may be shared with a further connection device  72 . 
         [0094]    In the seventh embodiment, it is said that the second optical connector  28  is an example “one of optical connectors”, and the first optical connector  26  is an example “the other optical connector”. However, it is also said that the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector” because light also passes through from the first optical connector  26  to the second optical connector  28 . In addition, the line arrangement box  38  is an example of “second mounting member”. 
         [0095]    A connection device  132  according to an eighth embodiment is described below. As illustrated in  FIG. 11 , in the connection device  132  according to the eighth embodiment, an intermediate plate  124  is provided inside the housing  20 . One or more substrates  126  and one or more substrates  128  are inserted in the arrow A 1  directions from both sides of the intermediate plate  124 . The number of first optical connectors  26  that are provided in the substrate  126  is same as the number of second optical connectors  28  that are provided in the substrate  128 . Relay connectors  130  the number of which is same as the first optical connector  26  are provided in the intermediate plate  124 . The first optical connector  26  and the second optical connector  28  are connected to each other through the relay connector  130 . 
         [0096]    The light source  50  and the first optical fibers  46  are provided in the substrate  126 . In the example illustrated in  FIG. 11 , the single light source  50  is provided for the single substrate  22 , and the number of first optical fibers  46  is same as the number of first optical connectors  26 . In addition, light from the light source  50  is guided to the first optical connector  26  through the first optical fiber  46 . 
         [0097]    The window members  52  and the second optical fibers  48  are provided in the substrate  128 . In the example illustrated in  FIG. 11 , the number of window members  52  and the number of second optical fibers  48  are the same as the number of second optical connectors  28 . In addition, the light of the second optical connector  28  is guided from the second optical fiber  48  to the corresponding window member  52 . 
         [0098]    In the eighth embodiment, when the light source  50  emits light in a state in which the first optical connector  26  and the second optical connector  28  are connected to each other through the relay connector  130 , the light enters the first optical connector  26  through the first optical fiber  46 , passes through the relay connector  130 , and reaches the second optical connector  28 . In addition, the light reaches the window member  52  through the second optical fiber  48 . That is, in the eighth embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0099]    In the eighth embodiment, the first optical connector  26  is an example of “one of optical connectors”, and the second optical connector  28  is an example of “the other optical connector”. In addition, the substrate  126  is an example of “first mounting member”. 
         [0100]    A line arrangement device  142  according to a ninth embodiment is described below. As illustrated in  FIG. 12 , the line arrangement device  142  according to the ninth embodiment includes a line arrangement sheet  144 , instead of the line arrangement box  38  according to the first embodiment. An intermediate portion of a communication optical cable  44  is installed on the line arrangement sheet  144 . Similar to the first embodiment, using the communication optical cables  44 , rearrangement (line arrangement) is performed between the second optical connectors  28  and the external connectors  40 . 
         [0101]    The line arrangement device  142  according to the ninth embodiment is used instead of the line arrangement device  16  according to the first embodiment, and for example, the line arrangement sheet  144  is attached to the bottom surface or the side surface of the housing  20  (see  FIG. 3 ). As a result, the intermediate portion of the communication optical cable  44  is installed on the housing  20 . At that time, the second optical connector  28  protrudes outwardly from the housing  20  (protrudes to the right in  FIG. 12 ), but the second optical connector  28  may be connected to the first optical connector  26  in the housing  20  (see  FIGS. 3 to 10 ) by curving the communication light cable  44  upward. Thus, in the ninth embodiment, the optical connector pair  24  includes the first optical connector  26  (see  FIGS. 3 to 10 ) and the second optical connector  28 . 
         [0102]    In the ninth embodiment, the light source  50  and the first optical fiber  46  are provided in the substrate  22 . In addition, light from the light source  50  is guided to the first optical connector  26  through the first optical fiber  46 . The structure may be achieved, for example, by the structure according to the first embodiment illustrated in  FIGS. 3 and 4 . 
         [0103]    The second optical connectors  28  respectively corresponds to the window member  52  by one-to-one in the line arrangement device  142 . The second optical connectors  28  are respectively connected to the window members  52  through the second optical fibers  48 . The second optical fiber  48  guides light from a terminal in the second optical connector  28 , which is not used to transmit and receive an optical signal to and from the first optical connector  26 , to the window member  52 . 
         [0104]    In the ninth embodiment, when the light source  50  emits light in a state in which the first optical connector  26  and the second optical connector  28  are securely connected to each other, the light passes through from the first optical fiber  46  to the first optical connector  26 . In addition, the light reaches the window member  52  through from the second optical connector  28  to the second optical fiber  48 . That is, in the ninth embodiment, the connection state between the first optical connector  26  and the second optical connector  28  may be easily checked by visually recognizing the visual check section  54  of the window member  52 . 
         [0105]    In the above description, the structure in which the plurality of optical connector pairs  24  are provided is described as an example, but for example, the single optical connector pair  24  may be provided. That is, a structure may be employed in which, in the single optical connector pair  24  that includes the first optical connector  26  and the second optical connector  28 , light is guided to a terminal of one of the optical connectors by a guide light member, and the light that passes through a terminal of the other optical connector is visually recognized by a visual recognition member. In addition, even when the single optical connector pair  24  is provided, the connection state between the first of the optical connectors and the other optical connector is easily checked by visually recognizing light by the visual recognition member. 
         [0106]    The embodiments are described above, but are not limited to the above-described examples, and in addition to the above-described examples, various modifications can be made within a range not departing from the gist, of course. 
         [0107]    All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.