Patent Publication Number: US-2016223756-A1

Title: Connectored cable and method for manufacturing connectored cable

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This is a continuation application of application Ser. No. 14,255, 002, filed Apr. 17, 2014, which is a continuation of application Ser. No. 13/889,792, filed May 8, 2013, which issued as U.S. Pat. No. 8,740,476, which is a Bypass Continuation of International Application No. PCT/JP2012/063202 filed May 23, 2012, claiming priority based on Japanese Patent Application Numbers 2011-213144 filed Sep. 28, 2011, 2011-219450, filed Oct. 3, 2011 and 2011-240451 filed Oct. 3, 2011, the contents of all of which are incorporated herein by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present invention relates to a connectored cable and a method for manufacturing the connectored cable. 
     Background Art 
     To perform optical transmission between devices, for example, it is possible to use a scheme as follows: a photoelectric conversion portion that performs conversion between electrical and optical signals is provided in each device, an optical cable is connected to the photoelectric conversion portions with optical connectors, and optical signals is sent and received through this optical fiber cable. 
     This scheme has a problem that any dirt or foreign matter deposited on the optical connectors may degrade signals. Moreover, in this scheme, an optical fiber processing portion and a photoelectric conversion portion need to be provided in a device. Thus, a connectored cable has been proposed in which photoelectric conversion portions are provided on the connector side (PTL 1). 
     CITATION LIST 
     Patent Literature 
     [PTL 1] JP H5-226027A 
     SUMMARY OF THE INVENTION 
     Problem to be Solved by the Invention 
     In recent years, with the reduction in device sizes and the increase in the amount of information transmission, a need to accommodate an optical fiber within a small connector has been arising. On the other hand, in order to suppress damage to the optical fiber and the optical coupling portion when a tension is applied to the cable, it is necessary to secure a sufficient extra length of the optical fiber within the connector. 
     However, even when a sufficient extra length of the optical fiber is secured within the connector, if the optical fiber is in a state in which it is likely to move inside the connector, damage to the optical coupling portion cannot be suppressed. 
     It is an object of the present invention to suppress damage to the optical coupling portion while managing the extra length so that the optical fiber is unlikely to move inside the connector. 
     Means for Solving the Problem 
     In order to achieve the object, a first primary aspect of the invention is a connectored cable including: a cable having an optical fiber for transmitting an optical signal; and a connector that accommodates a substrate on which a photoelectric conversion portion that is optically coupled to an end face of the optical fiber is installed, and in which the optical fiber is wired so that at least three bent portions are formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at each of the bent portions, and so that one of two bent portions on a front side is located on a down side of the substrate and the other bent portion on the front side is located on an up side of the substrate, the front-rear direction referring to a direction in which the cable extends from the connector, a rear side referring to a side in which the cable extends as seen from the connector, the front side referring to an opposite side of the side in which the cable extends, the up side referring to a side of the photoelectric conversion portion as seen from the substrate, the down side referring to an opposite side of the side of the photoelectric conversion portion. 
     Other features of the invention will become clear through the following description and the accompanying drawings. 
     Effects of the Invention 
     According to the invention, it is possible to suppress damage to the optical coupling portion while managing the extra length of the optical fiber so that the optical fiber is less likely to move within the connector. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is an overall perspective view of a connectored cable  1  of an embodiment. 
         FIG. 2  shows plan views and side views of the connectored cable  1  of this embodiment. 
         FIG. 3  is a cross-sectional view of a composite cable  2  used in this embodiment. 
         FIG. 4  is a functional block diagram of the connectored cable  1  of this embodiment. 
         FIG. 5  is an exploded perspective view of a camera-side connector  10 . 
         FIG. 6  is a perspective view of a parent substrate  20 . 
         FIG. 7  is a perspective view of a child substrate  40  and its surroundings as seen obliquely from above. 
         FIG. 8A  is an explanatory diagram of an optical coupling portion  43  that optically couples a light-emitting portion  41  and an optical fiber  3 , and  FIG. 8B  is an explanatory diagram of bonded portions on an end portion of the optical fiber  3 . 
         FIG. 9  is a perspective view of a termination portion  12  of the camera-side connector  10  as seen obliquely from above. 
         FIG. 10  shows a state in which a protective cover  51  shown in  FIG. 9  has been removed. 
         FIG. 11  is a perspective view of the termination portion  12  of the camera-side connector  10  as seen obliquely from below. 
         FIG. 12A  is a side view of the termination portion  12  as seen from the left, and  FIG. 12B  is a side view of the termination portion  12  as seen from the right. 
         FIG. 13  is an explanatory diagram of a leading end portion  3 I of the optical fiber  3  according to the embodiment and a reference example. 
         FIG. 14  is an exploded perspective view of a grabber-side connector  110 . 
         FIG. 15  is a perspective view of a child substrate  140  of the grabber-side connector  110  and its surroundings as seen obliquely from above. 
         FIG. 16  is a perspective view of a termination portion  112  of the grabber-side connector  110  as seen obliquely from above. 
         FIG. 17  shows a state in which a protective cover  151  shown in  FIG. 16  has been removed. 
         FIG. 18  is a perspective view of the termination portion  112  of the grabber-side connector  110  as seen obliquely from below. 
         FIG. 19  is an explanatory diagram of a method for manufacturing the connectored cable  1 . 
         FIG. 20  is a perspective view of the termination portion  12  of the camera-side connector  10  according to a first modified example as seen obliquely from below. 
         FIG. 21  is a perspective view of the termination portion  12  of the camera-side connector  10  according to a second modified example as seen obliquely from above. 
         FIG. 22  shows the termination portion  112  of the grabber-side connector  110  according to a third modified example as seen obliquely from above. 
         FIG. 23  is a perspective view of the child substrate  40  of the camera-side connector  10  and its surroundings according to a fourth modified example as seen obliquely from above. 
         FIG. 24  is a perspective view of the child substrate  40  of the camera-side connector  10  and its surroundings according to a sixth modified example as seen obliquely. 
         FIG. 25  is a perspective view of the child substrate  40  of the camera-side connector  10  and its surroundings according to a seventh modified example as seen obliquely. 
         FIG. 26  is a reference diagram illustrating a case of extra length management with a single bent portion. 
     
    
    
     BEST MODE FOR CARRYING OUT THE INVENTION 
     At least the following matters will be made clear by the description of the present specification and the accompanying drawings. 
     (1) 
     A connectored cable will now be described. A connectored cable including: a cable having an optical fiber for transmitting an optical signal; and a connector that accommodates a substrate on which a photoelectric conversion portion that is optically coupled to an end face of the optical fiber is installed, and in which the optical fiber is wired so that at least three bent portions are formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at each of the bent portions, and so that one of two bent portions on a front side is located on a down side of the substrate and the other bent portion on the front side is located on an up side of the substrate, the front-rear direction referring to a direction in which the cable extends from the connector, a rear side referring to a side in which the cable extends as seen from the connector, the front side referring to an opposite side of the side in which the cable extends, the up side referring to a side of the photoelectric conversion portion as seen from the substrate, the down side referring to an opposite side of the side of the photoelectric conversion portion. 
     With this connectored cable, it is possible to suppress damage to the optical coupling portion while managing the extra length so that the optical fiber is less likely to move within the connector. 
     It is desirable that a recess is formed on an edge of the substrate, and that the optical fiber is wired between the lower side and the upper side of the substrate by passing through a space between an inner surface of the connector and the recess. With this configuration, the connector size can be reduced. 
     It is desirable that the photoelectric conversion portion is mounted on a child substrate that is different from the substrate, and that the photoelectric conversion portion is installed on the substrate by electrically connecting the substrate and the child substrate. This configuration facilitates wiring of the optical fiber. 
     It is desirable that the optical fiber is wired with being sandwiched between the substrate and the child substrate. With this configuration, it is possible to restrain movement of the optical fiber within the connector. 
     It is desirable that the bent portion that is formed on the rear side is located on the up side of the substrate with respect to the two bent portions on the front side, and that a portion between the two bent portions that are located on the up side of the substrate is sandwiched between the substrate and the child substrate. With this configuration, an end of the optical fiber is less likely to move, and damage to the optical coupling portion can be suppressed. 
     It is desirable that the optical fiber is bent between the bent portion that is located on the upper side of the substrate and the end face of the optical fiber, and that the end face of the optical fiber and the photoelectric conversion portion are coupled to each other in such a manner that the optical fiber is slanted at an acute angle with respect to the front-rear direction. With this configuration, the connector size can be reduced. 
     It is desirable that the substrate has a recessed portion that is obliquely formed with respect to the front-rear direction, that the optical fiber is arranged along the recessed portion, and that the end face of the optical fiber and the photoelectric conversion portion are coupled in such a manner that the optical fiber is slanted at an acute angle with respect to the front-rear direction. With this configuration, it is possible to avoid interference between the optical fiber and the substrate. 
     It is desirable that a portion of a coating of the optical fiber is located in the recessed portion, and the coating of the optical fiber and the substrate are bonded in the recessed portion. This configuration makes it easier to bond the optical fiber. 
     It is desirable that the photoelectric conversion portion is mounted on a child substrate that is different from the substrate, that the photoelectric conversion portion is installed on the substrate by electrically connecting the substrate and the child substrate, that the optical fiber is wired with a portion of the optical fiber being sandwiched between the substrate and the child substrate, and that a bending direction of the optical fiber in the bent portion that is located closer to the end face of the optical fiber than the sandwiched portion is the same as a bending direction of the optical fiber between that bent portion and the end face of the optical fiber. With this configuration, the end of the optical fiber is extremely unlikely to move. 
     It is desirable that the cable further includes a signal line, that the substrate includes a through hole for connecting an end portion of the signal line by through-hole connection, and that inside the connector, any of the bent portions is located above a coating of the signal line that is connected to the substrate by through-hole connection. With this configuration, damage to the optical fiber can be suppressed. 
     It is desirable that the substrate includes a rear-side through hole that is located on the side in which the cable extends and a front-side through hole that is formed on the front side with respect to the rear-side through hole, and that a direction in which the end portion of the signal line is inserted into the rear-side through hole is opposite to a direction in which the end portion of the signal line is inserted into the front-side through hole. With this configuration, signal lines can be distributed to both sides of the substrate. 
     It is desirable that any of the bent portions is located above the coating of the signal line that is connected to the rear-side through hole by through-hole connection. Although it is necessary to connect the signal line to the front-side through hole by through-hole connection while being curved, it is not necessary to connect the signal line to the rear-side through hole by through-hole connection while being curved. Therefore, the signal line and the bent portion can be wired in such a manner that they do not become bulky. 
     It is desirable that the photoelectric conversion portion is mounted on a child substrate that is different from the substrate, that the photoelectric conversion portion is installed on the substrate by electrically connecting the substrate and the child substrate to each other, and that on both sides of the bent portion that is located above the coating of the signal line, the optical fiber is wired with a portion of the optical fiber being sandwiched between the substrate and the child substrate. With this configuration, it is possible to suppress damage to the optical coupling portion while managing the extra length so that the optical fiber is unlikely to move within the connector. 
     A method will be described which is for manufacturing a connectored cable including a cable having an optical fiber for transmitting an optical signal, and a connector that accommodates a substrate on which a photoelectric conversion portion that is optically coupled to an end face of the optical fiber is installed. The method includes: preparing the cable; optically coupling the end face of the optical fiber and the photoelectric conversion portion to each other; and wiring the optical fiber so that at least three bent portions are formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at each of the bent portions, so that one of two bent portions on a front side is located on a down side of the substrate and the other bent portion on the front side is located on a up side of the substrate, the front-rear direction referring to a direction in which the cable extends from the connector, a rear side referring to a side in which the cable extends as seen from the connector, the front side referring to an opposite side of the side in which the cable extends, the up side referring to a side of the photoelectric conversion portion as seen from the substrate, the down side referring to an opposite side of the side of the photoelectric conversion portion. 
     With this manufacturing method, it is possible to manufacture a connectored cable in which damage to the optical coupling portion is less likely to occur. 
     (2) 
     In recent years, with the reduction in device sizes and the increase in the amount of information transmission, a need to accommodate an optical fiber within a small connector has been arising. On the other hand, in order to suppress damage to the optical fiber and the optical coupling portion when a tension is applied to the cable, it is necessary to secure a sufficient extra length of the optical fiber within the connector. Thus, it is an object of a second aspect of the invention to reduce the connector size while securing a sufficient extra length of the optical fiber within the connector. 
     In order to achieve the object, a second primary aspect of the invention is a connectored cable including a cable having an optical fiber and a connector that accommodates a photoelectric conversion portion that is optically coupled to an end face of the optical fiber, and in which a bent portion is formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at the bent portion, the front-rear direction referring to a direction in which the cable extends from the connector, wherein the optical fiber is bent between the bent portion and the end face of the optical fiber, and the end face of the optical fiber and the photoelectric conversion portion are coupled to each other in such a manner that the optical fiber forms an acute angle with respect to the front-rear direction. With this connectored cable, it is possible to reduce the connector size while securing a sufficient extra length of the optical fiber within the connector. 
     It is desirable that a substrate on which the photoelectric conversion portion is mounted is accommodated in the connector, that the substrate has a recessed portion that is obliquely formed with respect to the front-rear direction, that the optical fiber is arranged along the recessed portion, and that the end face of the optical fiber and the photoelectric conversion portion are coupled in such a manner that the optical fiber is slanted at an acute angle with respect to the front-rear direction. With this configuration, it is possible to avoid interference between the optical fiber and the substrate. 
     It is desirable that a portion of a coating of the optical fiber is located in the recessed portion, and that the coating of the optical fiber and the substrate are bonded in the recessed portion. This configuration makes it easier to bond the optical fiber. 
     It is desirable that the connector accommodates a child substrate on which the photoelectric conversion portion is mounted and a parent substrate on which the child substrate is installed and which is electrically connected to the child substrate. With this configuration, wiring of the optical fiber is facilitated. 
     It is desirable that the optical fiber is wired with being sandwiched between the parent substrate and the child substrate. With this configuration, it is possible to restrain movement of the optical fiber within the connector. 
     It is desirable that a bending direction of the optical fiber in the bent portion that is located closer to the end face of the optical fiber than the sandwiched portion is the same as a bending direction of the optical fiber between that bent portion and the end face of the optical fiber. With this configuration, the end of the optical fiber is extremely unlikely to move. 
     It is desirable that the optical fiber is wired inside the connector so that at least three bent portions are formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at each of the bent portions, and so that one of two bent portions on a front side is located on a down side of the parent substrate and the other bent portion on the front side is located on an up side of the parent substrate, a rear side referring to a side in which the cable extends as seen from the connector, the front side referring to an opposite side of the side in which the cable extends, the up side referring to a side of the child substrate as seen from the parent substrate, the down side referring to an opposite side of the side of the child substrate. With this configuration, it is possible to suppress damage to the optical coupling portion while managing the extra length so that the optical fiber is unlikely to move within the connector. 
     It is desirable that the cable further includes a signal line, that the parent substrate includes a through hole for connecting an end portion of the signal line by through-hole connection, and that, when a side in which the cable extends as seen from the connector is defined as a rear side and the opposite side thereof is defined as a front side, a rear-side bent portion that is another bent portion is formed inside the connector on the rear side with respect to the bent portion, and the rear-side bent portion is located inside the connector above the coating of the signal line connected to the substrate by through-hole connection. With this configuration, damage to the optical fiber can be suppressed. 
     A method for manufacturing a connectored cable including a cable having an optical fiber, and a connector that accommodates a photoelectric conversion portion that is optically coupled to an end face of the optical fiber will be described. The method includes: preparing the cable; optically coupling the end face of the optical fiber and the photoelectric conversion portion to each other; and wiring the optical fiber so that a bent portion is formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at the bent portion, the front-rear direction referring to a direction in which the cable extends from the connector, and so that by bending the optical fiber between the bent portion and the end face of the optical fiber, the end face of the optical fiber and the photoelectric conversion portion are coupled to each other in such a manner that the optical fiber forms an acute angle with respect to the front-rear direction. 
     With this manufacturing method, it is possible to reduce the connector size while securing a sufficient extra length of the optical fiber within the connector. 
     (3) 
     Moreover, in recent years, with the reduction in device sizes and the increase in the amount of information transmission, a need to accommodate an optical fiber within a small connector has been arising. On the other hand, in order to suppress damage to the optical fiber and the optical coupling portion when a tension is applied to the cable, it is necessary to secure a sufficient extra length of the optical fiber within the connector. However, in the case where a signal line that transmits electrical signals is connected to a substrate within the connector by through-hole connection, there is a possibility that the optical fiber whose extra length is managed within the connector may be damaged when the optical fiber will come into contact with an edge of the solder of through-hole connection. Thus, it is an object of a third aspect of the invention to suppress damage to the optical fiber caused by an edge of the solder of through-hole connection while securing a sufficient extra length of the optical fiber within the connector. 
     In order to achieve the object, a third primary aspect of the invention is a connectored cable including: a cable having an optical fiber and a signal line; and a connector that accommodates a substrate including a through hole for connecting an end portion of the signal line by through-hole connection, in which a bent portion is formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at the bent portion, the front-rear direction referring to a direction in which the cable extends from the connector, and in which the bent portion is located above a coating of the signal line connected to the substrate by through-hole connection. With this connectored cable, it is possible to suppress damage to the optical fiber caused by an edge of the solder of through-hole connection while securing a sufficient extra length of the optical fiber within the connector. 
     It is desirable that, when a side in which the cable extends as seen from the connector is defined as a rear side and the opposite side thereof is defined as a front side, the substrate includes a rear-side through hole that is located on the side in which the cable extends and a front-side through hole that is formed on the front side with respect to the rear-side through hole, and a direction in which the end portion of the signal line is inserted into the rear-side through hole is opposite to a direction in which the end portion of the signal line is inserted into the front-side through hole. Thus, signal lines can be distributed to both sides of the substrate. 
     It is desirable that the bent portion is located above the coating of the signal line that is connected to the rear-side through hole by through-hole connection. Although it is necessary to connect the signal line to the front-side through hole by through-hole connection while being curved, it is not necessary to connect the signal line to the rear-side through hole by through-hole connection while being curved. Therefore, the signal line and the bent portion can be wired in such a manner that they do not become bulky. 
     It is desirable that a photoelectric conversion portion that is optically coupled to the end face of the optical fiber is mounted on a child substrate that is different from the substrate, and that the connector accommodates the substrate and the child substrate which are electrically connected. With this configuration, wiring of the optical fiber is facilitated. 
     It is desirable that the optical fiber is wired with being sandwiched between the substrate and the child substrate. With this configuration, it is possible to restrain movement of the optical fiber within the connector. 
     It is desirable that on both sides of the bent portion that is located above the coating of the signal line, the optical fiber is wired with a portion of the optical fiber being sandwiched between the substrate and the child substrate. This is particularly effective in the case of a configuration in which the bent portion is likely to be subject to a force toward the substrate. 
     It is desirable that the optical fiber is wired so that at least three bent portions are formed in the connector, the orientation of the optical fiber in the front-rear direction being changed, the optical fiber being bent into a U shape at each of the bent portions, and so that two bent portions on a front side are located in the connector on opposite sides of the substrate, a rear side referring to a side in which the cable extends as seen from the connector, the front side referring to an opposite side of the side in which the cable extends. With this configuration, it is possible to suppress damage to the optical coupling portion while managing the extra length so that the optical fiber is unlikely to move within the connector. 
     In the connector, it is desirable that a front-side bent portion that is another bent portion is formed on a side closer to the end face of the optical fiber than the bent portion, that the optical fiber is bent between the front-side bent portion and the end face of the optical fiber, and that the end face of the optical fiber is connected in such a manner that the optical fiber is slanted at an acute angle with respect to the front-rear direction. With this configuration, the connector size can be reduced. 
     A method for manufacturing a connectored cable including a cable having an optical fiber, and a connector that accommodates a substrate including a through hole for connecting an end portion of the signal line by through-hole connection will be described. The method includes: preparing the cable; connecting the end portion of the signal line to the through hole of the substrate by through-hole connection; and wiring the optical fiber so that a bent portion is formed, the orientation of the optical fiber in a front-rear direction being changed, the optical fiber being bent into a U shape at the bent portion, the front-rear direction referring to a direction in which the cable extends from the connector, and so that the bent portion is arranged above a coating of the signal line connected to the substrate by through-hole connection. With this manufacturing method, it is possible to manufacture a connectored cable in which damage to an optical fiber is less likely to occur. 
     Overall configuration 
       FIG. 1  is an overall perspective view of a connectored cable  1  according to an embodiment.  FIG. 2  shows a plan view and side views of the connectored cable  1  according to this embodiment. 
     The connectored cable  1  is composed of a composite cable  2  and two connectors provided on both ends of the composite cable  2 . The connectored cable  1  of this embodiment is configured so as to comply with the Camera Link interface; one connector serves as a camera-side connector (sender-side connector) and the other connector serves as a grabber-side connector  110  (receiver-side connector). The camera-side connector  10  and the grabber-side connector  110  each have a 26-pin connector terminal. 
     According to the Base Configuration, which is a type of Camera Link standard, signals (video signals and control signals) are transmitted between the camera-side connector  10  and the grabber-side connector  110  through a differential signal line composed of a metal cable. However, due to restrictions during transmission of video signals through differential signal lines, the Camera Link standard specifies that the maximum transmission distance is 10 m. In contrast, in this embodiment, video signals, which should be transmitted using a plurality of differential signal lines, are transmitted through an optical fiber by time division multiplexing. Thus, the connectored cable  1  of this embodiment can achieve a transmission distance of about 30 m. 
       FIG. 3  is a cross-sectional view of the composite cable  2  that is used in this embodiment. 
     The composite cable  2  includes a single optical fiber  3 , seven differential signal lines  4 , and two power supply lines  6 . The optical fiber  3  transmits optical signals. In the following description, a primary-coated optical fiber, a secondary-coated optical fiber, an optical fiber cord, and the like may also be referred to simply as “optical fiber”. Each differential signal line  4  is composed of a metal cable including a set of two signal lines  5 . Thus, the composite cable  2  includes a total of fourteen signal lines  5 . These differential signal lines  4  mainly transmit control signals, and so they transmit signals of lower frequencies than in the case of transmitting video signals. The two power supply lines  6  are each composed of a metal cable that is thicker than the signal lines  5 , and the potential of one power supply line  6  is 12 V, while the potential of the other power supply line  6  is GND. 
       FIG. 4  is a functional block diagram of the connectored cable  1  of this embodiment. 
     The camera-side connector  10  includes a light-emitting portion  41 , a driving portion  42 , an LVDS serializer  21 , and a camera-side MCU  22 . 
     The light-emitting portion  41  is a laser diode (LD). As the light-emitting portion  41  in this embodiment, employed is a Vertical Cavity Surface Emitting Laser (VCSEL), which emits light perpendicular to a substrate. The light-emitting portion  41  is driven by a current signal and outputs an optical signal to the optical fiber  3 , the current signal being the sum of a bias current and a modulation current output from the driving portion  42 . 
     The LVDS serializer  21  multiplexes by a time-division method four video signals (X 0  to X 3 ) and a clock signal (XCLK) for the video signals, and converts those signals into a serial signal. An optical signal corresponding to this serial signal is transmitted through the optical fiber  3 . 
     The camera-side MCU  22  performs, for example, (1) acquiring temperature data and bias current data, the temperature data being indicative of the ambient temperature of the light-emitting portion  41 , the bias current data being the monitor information of the magnitude of the bias current output to the light-emitting portion  41 , (2) sending the temperature data and the bias current data to a grabber-side MCU  122  through a differential signal line  4 , (3) acquiring from the grabber-side MCU  122  through a differential signal line  4  setting data of the bias current and setting data of the modulation current, for controlling the intensity of an optical signal originating from the light-emitting portion  41 , (4) setting the bias current and the modulation current of the light-emitting portion  41  based on the setting data of the bias current and the setting data of the modulation current, (5) acquiring from the grabber-side MCU  122  through a differential signal line  4  a LOCK signal which provides a notice that regeneration of a received clock at an LVDS deserializer  121  of the grabber-side connector  110  has been completed, and (6) outputting the LOCK signal to the LVDS serializer  21 . 
     The grabber-side connector  110  includes a light-receiving portion  141 , a current-to-voltage converting portion  142 , the LVDS deserializer  121 , and the grabber-side MCU  122 . 
     The light-receiving portion  141  is a photodiode (PD). In this embodiment, a GaAs PIN photodiode (PIN-PD) is adopted as the light-receiving portion  141 . 
     The current-to-voltage converting portion  142  outputs to the LVDS deserializer  121  a voltage signal corresponding to a current supplied from the light-receiving portion  141 . Moreover, the current-to-voltage converting portion  142  outputs to the grabber-side MCU  122  a monitor voltage corresponding to the current supplied from the light-receiving portion  141 . 
     The LVDS deserializer  121  generates four video signals (X 0  to X 3 ) and a clock signal (XCLK) for the video signals based on the voltage signal (serial signal) input from the current-to-voltage converting portion  142 , and outputs the generated signal to a grabber (not shown). 
     The grabber-side MCU  122  performs, for example, (1) detecting the state (normal or abnormal) of the light-emitting portion  41  by monitoring the monitor voltage, (2) acquiring a LOCK signal from the LVDS deserializer  121  and sending the LOCK signal to the camera-side MCU  22  through the differential signal line  4 , (3) acquiring the temperature data and the bias current data from the camera-side MCU  22  through the differential signal line  4 , and (4) generating the setting data of the bias current and the setting data of the modulation current based on the temperature data and the bias current data, and sending the generated setting data to the camera-side MCU  22  through the differential signal line  4 . 
     In order to provide the camera-side connector  10  and the grabber-side connector  110  with the functionality shown in  FIG. 4 , it is required that both the optical fiber  3  and the metal cables (the differential signal lines  4  and the power supply lines  6 ) are connected to substrates within the respective connectors. In this embodiment, to facilitate connecting operations of the optical fiber  3  and of the metal cables, child substrates to which the optical fiber  3  is connected are prepared in addition to parent substrates to which the metal cables are connected. Moreover, the child substrates to which the optical fiber  3  has been connected are installed on (connected to) the respective parent substrates to which the metal cables have been connected. 
     It should be noted that, the light-emitting portion  41  serving as a photoelectric conversion portion is mounted on the child substrate of the camera-side connector  10 . Moreover, the light-receiving portion  141  serving as a photoelectric conversion portion is mounted on the child substrate of the grabber-side connector  110 . 
     Camera-side Connector  10  Configuration 
       FIG. 5  is an exploded perspective view of the camera-side connector  10 . The camera-side connector  10  includes a housing  11  and a termination portion  12 . 
     The housing  11  is for covering the termination portion  12 , which is an electronic component. An inlet for introducing the composite cable  2  into the housing  11  is formed in the housing  11 . A caulking member  8  in the vicinity of a stripping portion  7  of the composite cable  2  is held in the inlet of the housing  11 . The housing  11  has a case  11 A and a cover  11 B. The case  11 A accommodates the termination portion  12 ; after placing the termination portion  12  in the case  11 A, an accommodating portion of the case  11 A is covered with the cover  11 B, and then the case  11 A and the cover  11 B are fastened to each other by screws. 
     The termination portion  12  includes a parent substrate  20 , a child substrate  40 , and a terminal portion  52 . The parent substrate  20  and the child substrate  40  are each a printed circuit board and achieve the respective functionalities shown in  FIG. 3 . The configurations of the parent substrate  20  and the child substrate  40  will be described later. To one end side of the parent substrate  20 , connected is the terminal portion  52 , which includes a 26-pin connector. On the other end side of the parent substrate  20 , the composite cable  2  is disposed. 
     In the following description of the camera-side connector  10 , the directions, front, rear, up, down, left, and right are defined as indicated in the drawing. That is to say, the direction of the composite cable  2  when extending straight from the camera-side connector  10  is defined as the “front-rear direction”, a direction of the composite cable  2  as seen from the camera-side connector  10  is defined as “rear”, and the opposite direction is defined as “front”. Moreover, the direction perpendicular to the parent substrate  20  is defined as the “up-down direction”, a direction of the child substrate  40  (the side on which the light-emitting portion  41  serving as a photoelectric conversion portion is present) as seen from the parent substrate  20  is defined as “up”, and the opposite direction is defined as “down” (in this drawing, the positional relationship is upside down). Moreover, the direction that is perpendicular to the front-rear direction and the up-down direction is defined as the “left-right direction”, and “right” and “left” are defined as indicated in the drawing (the right-hand side as seen from the front side in a state in which “up” is facing upward and “down” is facing downward in the up-down direction is defined as “right”, and the left-hand side is defined as “left”). 
     Configuration of Parent Substrate  20   
       FIG. 6  is a perspective view of the parent substrate  20 . 
     There are three rows (through hole rows) of through holes that are aligned in the left-right direction on the rear side (the composite cable  2  side) of the parent substrate  20 . The rearmost through hole row of the three through hole rows may be referred to as “rear-side through hole row  31 A”, and the other two through hole rows which are placed forward of the rear-side through hole row  31 A are referred to as “front-side through hole rows  32 A”. 
     The rear-side through hole row  31 A consists of six through holes. These six through holes may be referred to as “rear-side through holes  31 ”. The front-side through hole rows  32 A each consist of four through holes. The through holes of the front-side through hole rows  32 A may be referred to as “front-side through holes  32 ”. 
     Thus, there is provided a total of fourteen through holes (i.e., the six rear-side through holes  31  and the eight front-side through holes  32 ) on the rear side of the parent substrate  20 . These through holes are the through holes for soldering of the signal lines  5  constituting the differential signal lines  4  of the composite cable  2 . 
     A recess  24  is formed on the right edge of the parent substrate  20 . When the parent substrate  20  is stored in the housing  11 , there is almost no space between the inner surface of the housing  11  and the left and right edges of the parent substrate  20 , but in the recess  24 , a space is created between the parent substrate  20  and the inner surface of the housing  11 . The optical fiber  3  is wired through this space, and this makes it possible to secure an extra length of the optical fiber  3  on both upper and lower sides of the parent substrate  20  (wiring of the optical fiber  3  will be described later). 
     Two through holes  33  for a 2-pin header are formed on the right side of the parent substrate  20 , aligned in the front-rear direction. These two through holes are formed at a distance of a predetermined length from the right edge of the parent substrate  20 , so that when the parent substrate  20  is stored in the case  11 A of the housing  11 , the optical fiber  3  can be wired between a 2-pin header  61  and the inner surface of the housing  11 . 
     Ten through holes  34  for a 10-pin header are formed on the left side of the parent substrate  20 , aligned in the front-rear direction. The ten through holes are formed at a distance of a predetermined length from the left edge of the parent substrate  20 , so that when the parent substrate  20  is stored in the case  11 A of the housing  11 , the optical fiber  3  can be wired between a 10-pin header  62  (not shown) and the inner surface of the housing  11 . 
     Four through holes  35  for a 4-pin header and two through holes  36  for soldering of the power supply lines  6  of the composite cable  2  are formed in the parent substrate  20 . The through holes  36  for the power supply lines are located closest to a connecting portion  25  to which the terminal portion  52  is connected. The purpose of this is to minimize the power supply wiring pattern on the parent substrate  20 . Reducing the power supply wiring pattern reduces the number of portions at which the clearance from the signal pattern should be taken into account, and it is therefore possible to reduce the size of the substrate. 
     Configuration of Child Substrate  40   
       FIG. 7  is a perspective view of the child substrate  40  and its surroundings as seen obliquely from above. On the child substrate  40 , installed are mainly optical components (the light-emitting portion  41  and the driving portion  42  (not shown in  FIG. 7 ) thereof). The light-emitting portion  41  installed on the child substrate  40  is optically coupled to an end face of the optical fiber  3 . 
     The child substrate  40  is installed on the upper side of the parent substrate  20  with the 2-pin header  61 , the 10-pin header  62 , and the 4-pin header  63 . For this purpose, the child substrate  40  also has through holes for a 2-pin header, through holes for a 10-pin header, and through holes for a 4-pin header formed thereon. 
     The child substrate  40  has a recessed portion  44  formed thereon. The recessed portion  44  is a cut that is formed to avoid interference of a coating of the secondary-coated optical fiber of the optical fiber  3  with the child substrate  40  when optically coupling the end face of the optical fiber  3  to the light-emitting portion  41 . The width of the recessed portion  44  is set to be wider than the outer diameter, 900 μm, of the optical fiber  3  (including the coating of the secondary-coated optical fiber). Thus, the length L from the end face of the optical fiber  3  to the coating of the secondary-coated optical fiber can be reduced, and damage to the optical fiber  3  can be suppressed. Moreover, a portion of the coating of the optical fiber  3  can be positioned in the recessed portion  44 , so that the child substrate  40  and the coating of the optical fiber  3  can be fixed to each other by bonding (this will be described later). 
     The recessed portion  44  is obliquely formed with respect to the front-rear direction and the left-right direction. That is to say, the cutting direction of the recessed portion  44  has a relationship of 0°&lt;θ&lt;90° with respect to the front-rear direction. Preferably, the cutting direction of the recessed portion  44  has a relationship of 30°&lt;θ&lt;60° with respect to the front-rear direction. Here, the cutting direction of the recessed portion  44  is slanted at an angle of 45° with respect to the front-rear direction. 
     Thus, the recessed portion  44  is formed so that an opening portion thereof faces the right front side. As a result, when the child substrate  40  is stored in the housing  11 , the opening portion of the recessed portion  44  faces the inner surface of the right side of the housing  11  (the inner surface of the right side of the case  11 A). Obliquely forming the recessed portion  44  enables the optical fiber  3  to connect to the child substrate  40  in such a manner that it forms an acute angle with respect to the front-rear direction. 
     The light-emitting portion  41  is mounted on the extension of the recessed portion  44 . The light-emitting portion  41  is optically coupled to the end face of the optical fiber  3 , which is guided along the recessed portion  44  onto the child substrate  40 . 
       FIG. 8A  is an explanatory diagram of an optical coupling portion  43  that optically couples the light-emitting portion  41  and the optical fiber  3  to each other. The optical axis of the optical fiber  3  is approximately parallel to the child substrate  40 , and the optical axis of the light-emitting portion  41  is approximately perpendicular to the plane of the child substrate  40 . Therefore, these optical axes are arranged approximately perpendicular to each other. It should be noted that the structure and the like of the optical coupling portion  43  are also described in JP  2010 - 237642 A and WO 2011/83812. 
     The optical coupling portion  43  is composed of a resin that is transparent to the transmitted light. However, since the optical path within the resin through which the light is transmitted is short, it is sufficient that the resin is to some extent transparent. The optical coupling portion  43  covers the entire end face  3 J of the optical fiber  3  and is attached up to an upper portion of the optical fiber  3 . However, it is sufficient to cover the entire cross section of the core of the optical fiber  3  with the optical coupling portion  43 , and it is not necessarily required that it completely covers the end face  3 J of the optical fiber  3 . Similarly, it is sufficient to cover a light-emitting face  41 A of the light-emitting portion  41  with the optical coupling portion  43 , and it is not necessarily required that it completely covers the light-emitting portion  41 . 
     An outer surface  431  of the optical coupling portion  43  serves as an interface between the transparent resin composing the optical coupling portion  43  and outside gases (air, nitrogen, and the like). The light emitted from the light-emitting portion  41  is reflected from the outer surface  431  and enters the optical fiber  3 . The transparent resin composing the optical coupling portion  43  is not present in the position of an intersection P at which the optical axis of the optical fiber  3  and the optical axis of the light-emitting portion  41  intersect each other. The outer surface  431  of the optical coupling portion  43  has a concave shape that is recessed toward the end face  3 J of the optical fiber  3  and the light-emitting face  41 A of the light-emitting portion  41 . Specifically, the shape of the outer surface  431  of the optical coupling portion  43  is concave at a position A opposing the light-emitting face  41 A of the light-emitting portion  41  and at a position B opposing the end face of the optical fiber  3 , and is also concave between the positions A and B. 
     Since the transparent resin composing the optical coupling portion  43  is not present in the position of the intersection P at which the optical axis of the light-emitting portion  41  and the optical axis of the optical fiber  3  intersect each other, the range of light diffusion is narrowed, so that loss can be reduced. Moreover, since the outer surface  431  of the optical coupling portion  43  has a concave shape, it is no longer necessary to precisely control the position and the angle of the outer surface  431  serving as a reflection surface, and reliable optical coupling can be realized with lower manufacturing precision. Moreover, since the end face  3 J of the optical fiber  3  and the light-emitting portion  41  are optically coupled to each other by the optical coupling portion  43  composed of a single transparent resin, manufacturing is possible at an extremely low cost and through a simple manufacturing process. 
       FIG. 8B  is an explanatory diagram of bonded portions of the end portion of the optical fiber  3 . At least two portions of the end portion of the optical fiber  3  are fixed by bonding. 
     A first bonded portion is a portion at which the end face  3 J of the optical fiber  3  and the light-emitting portion  41  are fixed to each other by bonding. The transparent resin composing the above-described optical coupling portion  43  serves as an adhesive, thereby composing the first bonded portion. For this purpose, a material having the function of composing the optical coupling portion  43  and the function of an adhesive is adopted as the transparent resin for the first bonded portion. For example, a UV curing resin, a thermosetting resin, or the like can be used as the transparent resin. Specific examples thereof include an acrylic resin, an epoxy resin, and a silicone resin. 
     A second bonded portion is a portion at which the coating of the optical fiber  3  and the child substrate  40  are fixed to each other by bonding. By fixing at this portion, movement of the end portion of the optical fiber  3  is suppressed, and the breakage of the optical coupling portion  43  is suppressed. It should be noted that the simple configuration of the optical coupling portion  43  as shown in  FIG. 8A  causes the optical axis of the optical fiber  3  to be close to the surface of the child substrate  40 , but interference of the optical fiber  3  (having an outer diameter of 900 μm) with the child substrate  40  is avoided because of the recessed portion  44  formed in the child substrate  40 . Therefore, a portion of the coating of the optical fiber  3  can be positioned in the recessed portion  44 . Thus, at the second bonded portion, the coating of the optical fiber  3  and the child substrate  40  can be bonded to each other. It should be noted that, for example, a thermoplastic resin or the like can be used as an adhesive for the second bonded portion. Specific examples thereof include a silicone resin and an epoxy resin. Unlike the transparent resin for the first bonded portion, the adhesive for the second bonded portion is not required to have the function of transmitting light. 
     Wiring of Optical Fiber  3   
     Next, wiring of the optical fiber  3  will be described. It is necessary to set the bend radius to be greater than a permissible bend radius and to accommodate the optical fiber  3  within a narrow connector (within the housing  11 ). 
       FIG. 9  is a perspective view of the termination portion  12  of the camera-side connector  10  as seen obliquely from above.  FIG. 10  shows a state in which a protective cover  51  shown in  FIG. 9  has been removed.  FIG. 11  is a perspective view of the termination portion  12  of the camera-side connector  10  as seen obliquely from below.  FIG. 12A  is a side view of the termination portion  12  as seen from the left.  FIG. 12B  is a side view of the termination portion  12  as seen from the right. 
     Here, various portions of the optical fiber  3  within the housing  11  may be referred to as follows: a base portion  3 A; a lower-side linear portion  3 B; a first front-side bent portion  3 C; a transition portion  3 D; a first upper-side linear portion  3 E, a rear-side bent portion  3 F; a second upper-side linear portion  3 G; a second front-side bent portion  3 H; and a leading end portion  3 I, in this order from the stripping portion  7  of the composite cable  2  toward the end portion of the optical fiber  3 . The base portion  3 A is a portion between the stripping portion  7  and the lower-side linear portion  3 B. The lower-side linear portion  3 B is a portion that is wired approximately linearly on the left lower side of the parent substrate  20 . The first front-side bent portion  3 C is a bent portion that is bent into a U shape on the front lower side of the parent substrate  20 . The transition portion  3 D is a portion that is connected from the lower side to the upper side of the parent substrate  20  in the recess  24  of the parent substrate  20 . The first upper-side linear portion  3 E is a portion between the transition portion  3 D and the rear-side bent portion  3 F and is wired approximately linearly on the right upper side of the parent substrate  20 . The rear-side bent portion  3 F is a bent portion that is bent into a U shape on the rear upper side of the parent substrate  20 . The second upper-side linear portion  3 G is a portion between the rear-side bent portion  3 F and the second front-side bent portion  3 H and is wired approximately linearly on the left upper side of the parent substrate  20 . The second front-side bent portion  3 H is a bent portion that is bent into a U shape on the front upper side of the parent substrate  20 . The leading end portion  3 I is a portion between the second front-side bent portion  3 H and the optical coupling portion  43 . 
     The extra length of the optical fiber  3  is managed by approximately two loops within the housing  11 . Thus, the optical fiber  3  is routed within the housing  11  so that the orientation thereof in the front-rear direction is changed three times . As a result, the optical fiber  3  within the housing  11  has three bent portions (the first front-side bent portion  3 C, the rear-side bent portion  3 F, and the second front-side bent portion  3 H) that are bent into a U shape. These bent portions that are bent into a U shape prevent any tension applied to the composite cable  2  from being conveyed to the optical coupling portion  43  at the end portion of the optical fiber  3 , and therefore damage to the optical fiber  3  and the optical coupling portion  43  can be suppressed. 
     Since the optical fiber  3  is inserted from the rear side of the housing  11  while managing the extra length of two loops, two bent portions (the first front-side bent portion  3 C and the second front-side bent portion  3 H) of the three bent portions are located on the front side. If wiring is performed in the state where these two bent portions are stacked, the bent portions become bulky in the up-down direction. Moreover, the optical fiber  3  that is bulky in the up-down direction is likely to move within the housing  11  and causes a failure, such as damage to the optical coupling portion  43 . 
     To address this issue, in this embodiment, one of the two bent portions on the front side (the first front-side bent portion  3 C) is positioned on the lower side of the parent substrate  20 , and the other bent portion (the second front-side bent portion  3 H) is positioned on the upper side of the parent substrate  20 . That is to say, the optical fiber  3  is wired in such a manner that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 . In other words, the optical fiber  3  is wired in such a manner that the two bent portions on the front side are positioned on opposite sides of the parent substrate  20 . Thus, portions of the optical fiber  3  can avoid being stacked on both of the upper side and the lower side of the parent substrate  20 . Moreover, since the portions of the optical fiber  3  are not stacked, it is easy to immovably hold the optical fiber  3 . 
     In order to manage of the extra length of the optical fiber  3  on both of the upper side and the lower side of the parent substrate  20 , the recess  24  is formed in the parent substrate  20 . The recess  24  has a space formed between the parent substrate  20  and the inner surface of the housing  11 . The transition portion  3 D of the optical fiber  3  passes through this space, thereby the extra length of the optical fiber  3  are connected between the upper side and the lower side of the substrate. 
     The lower-side linear portion  3 B of the optical fiber  3  is wired outward (left) from the 10-pin header  62  and the power supply lines  6  (see  FIGS. 11 and 12A ). Thus, the lower-side linear portion  3 B is restrained in the left-right direction between the housing  11  and both of the 10-pin header  62  and the power supply lines  6 . As a result, movement of the optical fiber  3  within the housing  11  is restricted. 
     The first upper-side linear portion  3 E of the optical fiber  3  is wired outward (right) from the 2-pin header  61  (see  FIGS. 7, 9, 10, and 12B ). Thus, the first upper-side linear portion  3 E is restrained in the left-right direction between the housing  11  and the 2-pin header  61 . Furthermore, the first upper-side linear portion  3 E is wired between the parent substrate  20  and the child substrate  40  and is therefore restrained in the up-down direction as well. Accordingly, movement of the first upper-side linear portion  3 E in the left-right direction and the up-down direction is restricted. 
     The second upper-side linear portion  3 G of the optical fiber  3  is wired outward (left) from the 10-pin header  62  (see  FIG. 10 ). Thus, the second upper-side linear portion  3 G is restrained in the left-right direction between the housing  11  and the 10-pin header  62 . Furthermore, the second upper-side linear portion  3 G is wired between the parent substrate  20  and the child substrate  40  and is therefore restrained in the up-down direction as well. Accordingly, movement of the second upper-side linear portion  3 G in the left-right direction and the up-down direction is restricted. 
     The length of that portion of the second upper-side linear portion  3 G that is restrained in the left-right direction and the up-down direction is longer than the restrained portion of the first upper-side linear portion  3 E. Therefore, the second upper-side linear portion  3 G is unlikely to move within the housing  11 . That is to say, the second upper-side linear portion  3 G, which is closer to the end of the optical fiber  3  than the first upper-side linear portion  3 E is, is less movable than the first upper-side linear portion  3 E. Thus, damage to the optical coupling portion  43  that is caused by movement of the end of the optical fiber  3  within the housing  11  can be suppressed. 
     In order to suppress damage to the optical coupling portion  43  by increasing as much as possible the length of the second upper-side linear portion  3 G (increasing the length of the restrained portion), which is closer to the end of the optical fiber  3 , the rear-side bent portion  3 F is disposed on the upper side of the parent substrate  20  (the side on which the child substrate  40  is mounted). Moreover, in order to dispose the rear-side bent portion  3 F on the upper side of the parent substrate  20 , the transition portion  3 D (and the recess  24  of the parent substrate  20 ) is disposed opposite the second upper-side linear portion  3 G (on the right side) in the left-right direction. 
       FIG. 13  is an explanatory diagram showing the leading end portion  31  of the optical fiber  3  according to this embodiment and a comparative example. 
     The optical fiber  3  is bent into a U shape within the narrow housing  11 , and the starting point and the end point of the bent portion are both located very near the inner surface of the housing  11 . On the other hand, in order to mount the light-emitting portion  41  on the child substrate  40 , the optical coupling portion  43  needs to be positioned at a distance from the inner surface of the housing  11 . For this reason, the leading end portion  3 I beyond the second front-side bent portion  3 H needs to be wired from a position near the inner surface of the housing  11  to a position away from the inner surface of the housing  11 . 
     In the comparative example, the direction of optical fiber  3  in the optical coupling portion  43  is parallel to the front-rear direction. Thus, in the comparative example, the leading end portion  3 I of the optical fiber  3  beyond the second front-side bent portion  3 H needs to be bent twice. Consequently, in the comparative example, there is the necessity to increase the length of the leading end portion  3 I in the front-rear direction, which results in increase of the length of the camera-side connector  10  in the front-rear direction. 
     In contrast, in this embodiment, the direction of the optical fiber  3  in the optical coupling portion  43  is slanted at an angle θ with respect to the front-rear direction (θ is an acute angle (within a range of 0°&lt;θ&lt;90°, and is 45° in this example). Thus, in this embodiment, it is sufficient to bend only once the leading end portion  3 I of the optical fiber  3 , which is beyond the second front-side bent portion  3 H. Accordingly, in this embodiment, it is possible to reduce the length of the leading end portion  3 I in the front-rear direction, and it is possible to reduce the size of the camera-side connector  10 . 
     In order to eliminate the need to bend the leading end portion  31  of the optical fiber  3  more than once, the cutting direction of the recessed portion  44  in the child substrate  40  is slanted at an angle θ (45° in this example) with respect to the front-rear direction. Thus, the end face of the optical fiber  3  and the light-emitting portion  41  are optically coupled to each other in such a manner that the optical fiber  3  forms an acute angle with respect to the front-rear direction in the optical coupling portion  43 . 
     Moreover, in the comparative example, the leading end portion  3 I of the optical fiber  3  is bent into an S shape, and the leading end portion  31  of the optical fiber  3  is bent in different directions at the two positions (when seen from above as shown in  FIG. 13 , the optical fiber  3  is bent counterclockwise at one position and clockwise at the other position with respect to the direction toward the end face of the optical fiber  3 ). As in this comparative example, if portions that are bent in different directions are adjacent, the optical fiber  3  is more likely to move. For this reason, in the comparative example, it is necessary to increase the number of supporting points (e.g., bonding) for stably storing the optical fiber  3  or other means. 
     In contrast, in this embodiment, since the leading end portion  3 I of the optical fiber  3  is bent only once, there is no chance that portions that are bent in different directions are adjacent to each other in the leading end portion  3 I. Thus, the leading end portion  3 I of the optical fiber  3  is less movable than that in the comparative example. 
     Furthermore, in this embodiment, the direction in which the leading end portion  3 I of the optical fiber  3  is bent is the same as the direction in which the second front-side bent portion  3 H of the optical fiber  3  is bent. When seen from above as shown in  FIG. 13 , both the second front-side bent portion  3 H and the leading end portion  3 I of the optical fiber  3  are bent counterclockwise with respect to the direction toward the end face of the optical fiber  3 . That is to say, in this embodiment, the optical fiber  3  is bent in the same direction between the second upper-side linear portion  3 G and the optical coupling portion  43  (the second bonded portion in  FIG. 8B ); the optical fiber  3  in the second upper-side linear portion  3 G is restrained in the up-down direction and the left-right direction, and the optical coupling portion  43  is fixed to the optical fiber  3  by bonding. Thus, between the second upper-side linear portion  3 G and the optical coupling portion  43  (the second bonded portion in  FIG. 8B ), a configuration that makes the optical fiber  3  very unlikely to move is achieved because of the bending elastic force of the optical fiber  3 . 
     By wiring the optical fiber  3  as described above, it is possible to stably store long optical fiber  3  within the narrow housing  11  without using a cable clamp and the like or increasing the number of bonded portions. 
     Arrangement of Signal Lines  5  and Power Supply Lines  6   
     Next, wiring of the signal lines  5  and the power supply lines  6  will be described using  FIGS. 7, 9 to 11, 12A, and 12B . 
     The fourteen signal lines  5  are connected to the parent substrate  20  by through-hole connection. The reason for employing connection by through-hole connection, and not surface mounting, is to prevent the signal lines  5  from easily disconnecting from the parent substrate  20  even when a tension is applied to the cable  2 . 
     Six signal lines  5  of the fourteen signal lines  5  are respectively connected to the six rear-side through holes  31  by through-hole connection. The end portions of these six signal lines  5  are inserted downward into the rear-side through holes  31  and are soldered. The other eight signal lines  5  are respectively connected to the eight front-side through holes  32  by through-hole connection. End portions of these eight signal lines  5  are inserted upward into the front-side through holes  32  and are soldered. 
     That is to say, soldering of the rear-side through holes  31  and soldering of the front-side through holes  32  are performed in opposite directions. Thus, the fourteen signal lines  5  can be distributed to both sides of the parent substrate  20 , which facilitates the operation for connecting the signal lines  5  in a small region. Moreover, since the signal lines  5  are connected from both sides of the parent substrate  20  by through-hole connection, the signal lines  5  are less likely to disconnect from the parent substrate  20  even when a tension is applied to the signal lines  5 . 
     Furthermore, the end portions of all of the six signal lines  5  connected to the rear-side through holes  31  are inserted downward into the rear-side through holes  31  from above. That is to say, the end portions of these six signal lines  5  are inserted from the upper side of the parent substrate  20 , on which the rear-side bent portion  3 F of the optical fiber  3  is present. Thus, the rear-side bent portion  3 F of the optical fiber  3  does not come into contact with edges of the solder protruding from the rear-side through holes  31 , and therefore can be prevented from being damaged. Moreover, the rear-side bent portion  3 F is wired above the coatings of the six signal lines  5 . Therefore, even if the rear-side bent portion  3 F comes into contact with the signal lines  5 , the coatings of the signal lines  5  serve as cushioning materials, so that damage is unlikely to occur. 
     On respective sides of the rear-side bent portion  3 F that lies over the coatings of the six signal lines  5 , located are the first upper-side linear portion  3 E and the second upper-side linear portion  3 G; both of the first upper-side linear portion  3 E and the second upper-side linear portion  3 G are wired so as to be sandwiched between the parent substrate  20  and the child substrate  40 . Since the first upper-side linear portion  3 E and the second upper-side linear portion  3 G is subject to a downward force from the child substrate  40 , the rear-side bent portion  3 F is likely to be subject to a downward force, which is located between the first upper-side linear portion  3 E and the second upper-side linear portion  3 G. That is, if an edge of the solder is present below the rear-side bent portion  3 F, it is likely to cause damage to the optical fiber  3 . Therefore, as in this embodiment, in a configuration in which both of the first upper-side linear portion  3 E and the second upper-side linear portion  3 G are wired so as to be sandwiched between the parent substrate  20  and the child substrate  40 , it is particularly effective in preventing damage to the optical fiber  3  that the rear-side bent portion  3 F is located above the coatings of the signal lines  5 . 
     The six signal lines  5  that are connected to the rear-side through holes  31  are connected by through-hole connection without being curved. In contrast, the eight signal lines  5  are connected to the front-side through holes  32  by through-hole connection while being slightly curved (see  FIG. 12B ). The reasons for this are as follows: (1) when connecting the eight signal lines  5  to the front-side through holes  32 , it is necessary to wire those signal lines  5  over the lower side of the edges of the solders which protrude from the rear-side through holes  31 , and (2) when the soldering of the rear-side through holes  31  is visually inspected from the lower side of the parent substrate  20 , it is necessary to allow the eight signal lines  5  connected to the front-side through holes  32  to be shifted in the left-right direction. 
     The rear-side bent portion  3 F is arranged above the coatings of the six signal lines  5  that are connected to the rear-side through holes  31  by through-hole connection without being curved. Thus, the signal lines  5  and the rear-side bent portion  3 F can be wired in such a manner that they do not become bulky in the up-down direction. If the rear-side bent portion  3 F is arranged above the coatings of the eight signal lines  5  that are connected to the front-side through holes  32  by through-hole connection while being curved, not only the signal lines  5  and the rear-side bent portion  3 F become bulky in the up-down direction, but also the rear-side bent portion  3 F is wired at a distance from the parent substrate  20 . Therefore, there is a possibility that the optical fiber  3  is likely to move or that the bend radius of the rear-side bent portion  3 F decreases. 
     The two power supply lines  6  are connected by through-hole connection at positions that are closer to the terminal portion  52  than the signal lines  5  are. The purpose of this is to minimize the power supply wiring pattern on the parent substrate  20 . Moreover, the two power supply lines  6  are wired over the lower side of the 4-pin header  63 . However, coatings of the power supply lines  6  are thick when compared with the coatings of the signal lines  5 , and therefore damage due to contact with the pins is unlikely to occur. This is why the above-described wiring manner is permitted. 
     Grabber-side Connector  110   
     Next, the grabber-side connector  110  will be described. The configuration of the grabber-side connector  110  is similar to that of the camera-side connector  10 , and so various components of the grabber-side connector  110  are designated by reference numerals obtained by adding  100  to the reference numerals of the corresponding components of the camera-side connector  10 , and descriptions of those components may be omitted in some cases. 
     Configuration 
       FIG. 14  is an exploded perspective view of the grabber-side connector  110 . 
     In the following description of the grabber-side connector  110 , the directions, front, rear, up, down, left, andrightaredefinedas indicated in the drawing. That is to say, the direction of the composite cable  2  when extending straight from the grabber-side connector  110  is defined as the “front-rear direction”, a direction of the composite cable  2  as seen from the grabber-side connector  110  is defined as “rear”, and the opposite direction is defined as “front”. Moreover, the direction perpendicular to a parent substrate  120  is defined as the “up-down direction”, a direction of the child substrate  140  (the side on which the light-receiving portion  141  serving as a photoelectric conversion portion is present) as seen from the parent substrate  120  is defined as “up”, and the opposite direction is defined as “down”. Moreover, the direction that is perpendicular to the front-rear direction and the up-down direction is defined as the “left-right direction”, and “right” and “left” are defined as indicated in the drawing (the right-hand side as seen from the front side in a state in which “up” is positioned up and “down” is positioned down in the up-down direction is defined as “right”, and the left-hand side is defined as “left”). 
       FIG. 15  is a perspective view of the child substrate  140  of the grabber-side connector  110  and its surroundings as seen obliquely from above. It should be noted that instead of the light-emitting portion  41 , the light-receiving portion  141  is mounted on the child substrate  140  of the grabber-side connector  110 . 
     There are two rows of through holes that are aligned in the left-right direction on the rear side (the composite cable  2  side) of the parent substrate  120 . The through hole row on the rear side consists of six rear-side through holes  131 . The through hole row on the front side consists of eight front-side through holes  132 . It should be noted that the front-side through holes  132  of the grabber-side connector  110  are aligned in a single row, because the width of the parent substrate  120  of the grabber-side connector  110  in the left-right direction is greater than that of the camera-side connector  10 , and the eight front-side through holes  132  can be aligned in the left-right direction. 
     A recess  124  is formed on the right edge of the parent substrate  120 . When the parent substrate  120  is stored in a housing  111 , there is almost no space between the inner surface of the housing  111  and the left and right edges of the parent substrate  120 , but in the recess  124 , a space is created between the parent substrate  120  and the inner surface of the housing  111 . The optical fiber  3  is wired through this space, and this makes it possible to secure an extra length of the optical fiber  3  on both upper and lower sides of the parent substrate  120 . 
     The child substrate  140  has a recessed portion  144  formed thereon. The recessed portion  144  is a cut that is formed to avoid interference of a coating of the secondary-coated optical fiber of the optical fiber  3  with the child substrate  140  when optically coupling the end face of the optical fiber  3  to the light-receiving portion  141 . The width of the recessed portion  144  is set to be wider than the outer diameter, 900 μm, of the optical fiber  3  (including the coating of the secondary-coated optical fiber). Thus, the length L from the end face of the optical fiber  3  to the coating of the secondary-coated optical fiber can be reduced, and damage to the optical fiber  3  can be suppressed. Moreover, a portion of the coating of the optical fiber  3  can be positioned in the recessed portion  144 , so that the child substrate  140  and the coating of the optical fiber  3  can be fixed to each other by bonding. 
     The recessed portion  144  is obliquely formed with respect to the front-rear direction and the left-right direction. Here, the cutting direction of the recessed portion  144  is slanted at 45° with respect to the front-rear direction. Thus, the optical fiber  3  is connected to the child substrate  140  in such a manner that it forms an acute angle with respect to the front-rear direction. 
     The light-receiving portion  141  is mounted on the extension of the recessed portion  144 . The light-receiving portion  141  is optically coupled to the end face of the optical fiber  3 , which is guided along the recessed portion  144  onto the child substrate  140 . It should be noted that an optical coupling portion  143  that optically couples the light-receiving portion  141  and the optical fiber  3  has approximately the same configuration as the above-described optical coupling portion  43  shown in  FIG. 8A . Moreover, at least two bonded portions of an end portion of the optical fiber  3  are the same as those described above with reference to  FIG. 8B . 
     Wiring of Optical Fiber  3   
       FIG. 16  is a perspective view of a termination portion  112  of the grabber-side connector  110  as seen obliquely from above.  FIG. 17  shows a state in which a protective cover  151  in  FIG. 16  has been removed.  FIG. 18  is a perspective view of the termination portion  112  of the grabber-side connector  110  as seen obliquely from below. 
     The extra length of the optical fiber  3  is managed by approximately two loops within the housing  111 . Thus, the optical fiber  3  is routed within the housing  111  so that the orientation thereof in the front-rear direction is changed three times. As a result, the optical fiber  3  within the housing  111  has at least three bent portions (the first front-side bent portion  3 C, the rear-side bent portion  3 F, and the second front-side bent portion  3 H) that are bent into a U shape. These bent portions that are bent into a U shape prevent any tension applied to the composite cable  2  from being conveyed to the optical coupling portion  143  at the end portion of the optical fiber  3 , and therefore damage to the optical fiber  3  and the optical coupling portion  143  can be suppressed. 
     In this embodiment, one of the two bent portions on the front side (the first front-side bent portion  3 C) is positioned on the lower side of the parent substrate  120 , and the other bent portion (the second front-side bent portion  3 H) is positioned on the upper side of the parent substrate  120 . That is to say, the optical fiber  3  is wired in such a manner that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  120 . In other words, the optical fiber  3  is wired in such a manner that the two bent portions on the front side are positioned on opposite sides of the parent substrate  120 . Thus, portions of the optical fiber  3  can avoid being stacked on both of the upper side and the lower side of the parent substrate  120 . Moreover, since the portions of the optical fiber  3  are not stacked, it is easy to immovably hold the optical fiber  3 . 
     In order to manage of the extra length of the optical fiber  3  on both of the upper side and the lower side of the parent substrate  120 , the recess  124  is formed in the parent substrate  120 . The recess  124  has a space formed between the parent substrate  120  and the inner surface of the housing  111 . The transition portion  3 D of the optical fiber  3  passes through this space, thereby the extra length of the optical fiber  3  are connected between the upper side and the lower side of the substrate. 
     The second upper-side linear portion  3 G of the optical fiber  3  is wired outward (left) of a 10-pin header  162  (see  FIG. 17 ). Thus, the second upper-side linear portion  3 G is restrained in the left-right direction between the housing  111  and the 10-pin header  162 . Furthermore, the second upper-side linear portion  3 G is wired between the parent substrate  120  and the child substrate  140  and is therefore restrained in the up-down direction as well. Accordingly, movement of the second upper-side linear portion  3 G in the left-right direction and the up-down direction is restricted. 
     The length of that portion of the second upper-side linear portion  3 G that is restrained in the left-right direction and the up-down direction is long. Therefore, the second upper-side linear portion  3 G is unlikely to move within the housing  111 . Thus, damage to the optical coupling portion  143  that is caused by movement of the end of the optical fiber  3  within the housing  111  can be suppressed. 
     In order to suppress damage to the optical coupling portion  143  by increasing as much as possible the length of the second upper-side linear portion  3 G (increasing the length of the restrained portion), which is closer to the end of the optical fiber  3 , the rear-side bent portion  3 F is disposed on the upper side of the parent substrate  120  (the side on which the child substrate  140  is mounted). Moreover, in order to dispose the rear-side bent portion  3 F on the upper side of the parent substrate  20 , the transition portion  3 D (and the recess  124  of the parent substrate  120 ) is disposed opposite the second upper-side linear portion  3 G (on the right side) in the left-right direction. 
     In this embodiment, the direction of the optical fiber  3  in the optical coupling portion  143  is slanted at an angle θ with respect to the front-rear direction (θ is an acute angle (within a range of 0°&lt;θ&lt;90°, and is 45° in this example). Thus, in this embodiment, it is sufficient to bend only once the leading end portion  3 I of the optical fiber  3 , which is beyond the second front-side bent portion  3 H (see  FIG. 13 ). Therefore, in this embodiment, it is possible to reduce the length of the leading end portion  3 I in the front-rear direction, and it is possible to reduce the size of the grabber-side connector  110 . 
     In order to eliminate the need to bend the leading end portion  31  of the optical fiber  3  more than once, the cutting direction of the recessed portion  144  in the child substrate  140  is slanted at an angle θ(45° in this example) with respect to the front-rear direction. Thus, the end face of the optical fiber  3  and the light-receiving portion  141  are optically coupled to each other in such a manner that the optical fiber  3  forms an acute angle with respect to the front-rear direction in the optical coupling portion  143 . 
     By wiring the optical fiber  3  as described above, it is possible to stably store the long optical fiber  3  within the narrow housing  11  without using a cable clamp and the like or increasing the number of bonded portions. 
     Wiring of Signal lines  5  and Power supply lines  6   
     Next, wiring of the signal lines  5  and the power supply lines  6  will be described using  FIGS. 15 to 18 . 
     The fourteen signal lines  5  are connected to the parent substrate  120  by through-hole connection. The reason for employing connection by through-hole connection, and not surface mounting, is to prevent the signal lines  5  from easily disconnecting from the parent substrate  120  even when a tension is applied to the cable  2 . 
     Six signal lines  5  of the fourteen signal lines  5  are respectively connected to the six rear-side through holes  131  by through-hole connection. End portions of these six signal lines  5  are inserted downward into the rear-side through holes  131  and are soldered. The other eight signal lines  5  are respectively connected to the eight front-side through holes  132  by through-hole connection. End portions of these eight signal lines  5  are inserted upward into the front-side through holes  132  and soldered. 
     That is to say, soldering of the rear-side through holes  131  and soldering of the front-side through holes  132  are performed in opposite directions. Thus, the fourteen signal lines  5  can be distributed to both sides of the parent substrate  120 , which facilitates the operation for connecting the signal lines  5  in a small region. Moreover, since the signal lines  5  are connected from both sides of the parent substrate  120  by through-hole connection, the signal lines  5  are less likely to disconnect from the parent substrate  120  even when a tension is applied to the signal lines  5 . 
     Furthermore, the end portions of all of the six signal lines  5  connected to the rear-side through holes  131  are inserted downward into the rear-side through holes  131  from above. That is to say, the end portions of these six signal lines  5  are inserted from the upper side of the parent substrate  120 , on which the rear-side bent portion  3 F of the optical fiber  3  is present. Thus, the rear-side bent portion  3 F of the optical fiber  3  does not come into contact with edges of the solder protruding from the rear-side through holes  131  and therefore can be prevented from being damaged. Moreover, the rear-side bent portion  3 F is wired above the coatings of the six signal lines  5 . Therefore, even if the rear-side bent portion  3 F comes into contact with the signal lines  5 , the coatings of the signal lines  5  serve as cushioning materials, so that damage is unlikely to occur. 
     The six signal lines  5  that are connected to the rear-side through holes  131  are connected by through-hole connection without being curved (see  FIG. 17 ). In contrast, the eight signal lines  5  are connected to the front-side through holes  132  by through-hole connection while being slightly curved (see  FIG. 18 ). The reason for this is the same as described regarding wiring of the signal lines  5  in the camera-side connector  10 . 
     The rear-side bent portion  3 F is arranged above the coatings of the six signal lines  5  that are connected to the rear-side through holes  131  by through-hole connection without being curved. Thus, the signal lines  5  and the rear-side bent portion  3 F can be wired in such a manner that they do not become bulky in the up-down direction. 
     The two power supply lines  6  are connected by through-hole connection at positions that are closer to the terminal portion  152  than the signal lines  5  are. The purpose of this is to minimize the power supply wiring pattern on the parent substrate  120 . 
     Manufacturing Method 
       FIG. 19  is an explanatory diagram of a method for manufacturing the connectored cable  1 . 
     Preprocessing of Composite Cable  2   
     First, the composite cable  2  is prepared. Then, preprocessing of both ends of the composite cable  2  is performed. 
     In the preprocessing, a sheath on each end portion of the composite cable  2  is stripped off, and thereby the optical fiber  3 , the signal lines  5 , and the power supply lines  6  are exposed. In this embodiment, the optical fiber  3  is exposed from the composite cable  2  so that the exposed portion of the optical fiber  3  has a length sufficient to manage the extra length of two loops within a connector. 
     At each stripping portion  7  of the composite cable  2 , an adhesive is applied to a circumference of the optical fiber  3 , and the optical fiber  3 , the signal lines  5 , and the power supply lines  6  are bonded to one another (in the diagram, the bonded portions are indicated in black). Due to this bonding, even when a tension is applied to the composite cable  2 , it is possible to prevent the tension from being transferred beyond the stripping portion  7  of the composite cable  2 . 
     A metal ring is inserted into the stripping portion  7  of the composite cable  2 , and this metal ring is crimped, composing the caulking member  8 . Due to this caulking member  8 , even when a tension is applied to the composite cable  2 , it is possible to prevent the tension from being transferred beyond the stripping portion  7  of the composite cable  2 . 
     Connection of Optical Fiber  3   
     Next, an end portion of the optical fiber  3  is attached to child substrate  40  (and to the child substrate  140 ). At this time, first, a UV coating at the end portion of the optical fiber  3  is removed, and thereby the primary-coated optical fiber is exposed. An end portion of the primary-coated optical fiber is cut, and a termination of the optical fiber  3  is performed. The length from the end face of the optical fiber  3  to the coating of the secondary-coated optical fiber is L (see  FIGS. 7, 8B, and 15 ). Then, the terminated optical fiber  3  and the child substrate  40  are placed in an automatic alignment apparatus, the photoelectric conversion portion (the light-emitting portion  41 , the light-receiving portion  141 ) installed on the child substrate  40  and the end face of the optical fiber  3  are automatically aligned, and afterward the optical coupling portion  43  is formed (see  FIG. 8A ). After attaching the optical fiber  3  to the child substrate  40 , the protective cover  51  is attached to the child substrate  40  in order to protect the optical coupling portion  43 . Moreover, since the optical coupling portion  43  is likely to be damaged, the coating of the optical fiber  3  that is located in the recessed portion  44  of the child substrate  40  and the child substrate  40  are fixed to each other by bonding (see  FIG. 8B ). 
     In this embodiment, the child substrate  40  is separated from the parent substrate  20 , and this makes it possible to reduce the size of the substrate to be placed in the automatic alignment apparatus. Moreover, the child substrate  40  can have a shape that is independent of the shape and the size of the connector, so that the alignment process can be easily automated. 
     In this embodiment, the optical fiber  3  is exposed from the composite cable  2  so that the extra length of the optical fiber  3  is managed by two loops within the connector. However, there is a possibility that a failure may occur at the time of connecting the optical fiber  3  (for example, at the time of the termination work of the optical fiber  3 ). In such a case, the optical fiber  3  can be cut and shortened so that the extra length is reduced by an amount corresponding to one loop. In this case, as shown in a reference diagram of  FIG. 26 , the extra length can be managed by one bent portion; where normally there are three bent portions (the first front-side bent portion  3 C, the rear-side bent portion  3 F, and the second front-side bent portion  3 H). Thus, even if connection of the optical fiber  3  is failed once, it is not necessary to discard the composite cable  2 . 
     Connection of Signal Lines  5  and Power Supply Lines  6   
     Next, the signal lines  5  and the power supply lines  6  are soldered to the parent substrate  20  (and to the parent substrate  120 ). The terminal portion  52  is connected to the parent substrate  20  in advance. 
     First, the six signal lines  5  are respectively connected to the six rear-side through holes  31  by through-hole connection. The end portions of these six signal lines  5  are inserted downward into the rear-side through holes  31  and are soldered. The other eight signal lines  5  are respectively connected to the eight front-side through holes  32  by through-hole connection. The end portions of these eight signal lines  5  are inserted upward into the front-side through holes  32  and are soldered. Moreover, the two power supply lines  6  are also connected to the parent substrate  20  by through-hole connection. 
     In this embodiment, the parent substrate  20  and the child substrate  40  are separated from each other. This makes it possible to prevent a soldering iron from damaging the optical fiber at the time of soldering of the signal lines  5  and the power supply lines  6 . Also, it is possible to avoid contamination of the optical coupling portion  43  by flying flux or the like. 
     Moreover, in this embodiment, soldering of the rear-side through holes  31  and soldering of the front-side through holes  32  are performed in opposite directions. This facilitates the soldering operation of the signal lines  5 , and also the signal lines  5  becomes less likely to disconnect from the parent substrate  20 . 
     Moreover, since the eight signal lines  5  that are connected to the front-side through holes  32  are connected while being slightly curved, soldering of the rear-side through holes  31  can be visually inspected by shifting the eight signal lines  5  connected to the front-side through holes  32  in the left-right direction. 
     Connection between Parent Substrate and Child Substrate (Wiring of Optical Fiber  3 ) 
     Next, the parent substrate  20  and the child substrate  40  are connected to each other (the parent substrate  120  and the child substrate  140  are also connected to each other). At this time, wiring of the optical fiber  3  is also performed. 
     First, as shown in  FIG. 11  (or  FIG. 18 ), on the lower side of the parent substrate  20 , an operator places outward (left) of the 10-pin header  62  the optical fiber  3  which is near the stripping portion  7  of the composite cable  2 . Thus, the base portion  3 A is formed. Then, the operator wires the optical fiber  3  in the front-rear direction along the 10-pin header  62  and outward of the 10-pin header  62 . Thus, the lower-side linear portion  3 B is formed. Then, the operator changes the orientation of the optical fiber  3  in the front-rear direction and wires a U-shaped bent portion on the front lower side of the parent substrate  20 . Thus, the first front-side bent portion  3 C is formed. Subsequently, the operator wires the optical fiber  3  from the lower side to the upper side in the recess  24  of the parent substrate  20 , thereby forming the transition portion  3 D. 
     Then, as shown in  FIG. 9  (or  FIG. 16 ), on the upper side of the parent substrate  20 , the operator places the optical fiber  3  in the front-rear direction outward (right) of the 2-pin header  61 . Thus, the first upper-side linear portion  3 E is formed. Then, the operator changes the orientation of the optical fiber  3  in the front-rear direction and wires a U-shaped bent portion on the rear upper side of the parent substrate  20 . Thus, the rear-side bent portion  3 F is formed. The rear-side bent portion  3 F is arranged above the coatings of the six signal lines  5  connected to the rear-side through holes  31 . Then, the operator wires the optical fiber  3  in the front-rear direction along the 10-pin header  62  and outward of the 10-pin header  62 . Thus, the second upper-side linear portion  3 G is formed. Then, the operator changes the orientation of the optical fiber  3  in the front-rear direction and wires a U-shaped bent portion on the front upper side of the parent substrate  20 . Thus, the second front-side bent portion  3 H is formed. Then, the operator bends a portion of the optical fiber  3  beyond the second front-side bent portion  3 H once. Thus, the leading end portion  3 I is formed. The operator also installs the child substrate  40  on the parent substrate  20  with the 2-pin header  61 , the 10-pin header  62 , and the 4-pin header  63 . At the time of the installation of the child substrate  40  on the parent substrate  20 , the second upper-side linear portion  3 G is sandwiched between the parent substrate  20  and the child substrate  40 . Moreover, in the case of the camera-side connector  10 , the first upper-side linear portion  3 E also is sandwiched between the parent substrate  20  and the child substrate  40 . Due to sandwiching the optical fiber  3  between the parent substrate  20  and the child substrate  40 , it is possible to restrain the optical fiber  3  from moving in the up-down direction. 
     In this embodiment, the parent substrate  20  and the child substrate  40  are separated from each other, and therefore it is easy to wire the optical fiber in the above-described manner. 
     It should be noted that in the case of the camera-side connector  10 , both of the first upper-side linear portion  3 E and the second upper-side linear portion  3 G are wired so as to be sandwiched between the parent substrate  20  and the child substrate  40 . Therefore, at the time of the installation of the child substrate  40  on the parent substrate  20 , the rear-side bent portion  3 F is likely to be subject to a downward force. However, since the rear-side bent portion  3 F is arranged above the coatings of the signal lines  5 , the coatings of the signal lines  5  serve as cushioning materials, so that damage to the optical fiber  3  is suppressed. 
     After installing the child substrate  40  on the parent substrate  20 , the operator electrically connects the parent substrate  20  and the child substrate  40  by soldering of the pins of the 2-pin header  61 , the 10-pin header  62 , and the 4-pin header  63 . Thus, the termination portion  12  is completed. At this time, the protective cover  51  attached to the child substrate  40  prevents the soldering iron from damaging to the optical fiber. Also, it is possible to avoid contamination of the optical coupling portion  43  by flying flux and the like. 
     After the termination portion  12  has been completed, the case  11 A accommodates the termination portion  12 . Then, the operator covers the accommodating portion of the case  11 A with the cover  11 B, and fastens the case  11 A and the cover  11 B to each other by screws. Thus, the connectored cable  1  is completed. 
     MODIFIED EXAMPLES 
     First Modified Example 
     Example in which Number of Loops of Optical fiber  3  is Changed 
     In the foregoing embodiment, the extra length of the optical fiber  3  is managed by approximately two loops within the connector, and there were three bent portions within the connector. However, a method for managing the extra length of the optical fiber  3  within the connector is not limited to this. The extra length of the optical fiber  3  may also be managed by three or more loops within the connector. 
       FIG. 20  is a perspective view of the termination portion  12  of the camera-side connector  10  according to the first modified example as seen obliquely from below. It should be noted that the configuration and wiring on the upper side of the parent substrate  20  are the same as those of the above-described embodiment and therefore are omitted from the drawing. 
     In the first modified example, the extra length of the optical fiber  3  is managed by approximately three loops within the housing  11 . Thus, the optical fiber  3  is routed within the housing  11  so that the orientation thereof in the front-rear direction is changed five times. As a result, the optical fiber  3  within the housing  11  has five bent portions that are bent into a U shape. Among the five bent portions, three bent portions are located on the front side, and two bent portions are located on the rear side. Among the three bent portions that are located on the front side, one bent portion is located on the upper side of the parent substrate  20  (not shown in  FIG. 20 ), and two bent portions are located on the lower side of the parent substrate  20 . Moreover, one of the two bent portions on the rear side is located on the upper side of the parent substrate  20  (not shown in  FIG. 20 ), and the other is located on the lower side of the parent substrate  20 . 
     In the first modified example, the optical fiber  3  are wired so that the three bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 . Thus, in the first modified example, when compared with a case where the three bent portions are disposed on only either side of the parent substrate  20 , the optical fiber  3  can avoid becoming bulky in the up-down direction, and the optical fiber  3  is less likely to move within the housing  11 . 
     Moreover, in the first modified example, if the direction of the optical fiber  3  in the optical coupling portion  43  is slanted at an acute angle θ (for example, 45°) with respect to the front-rear direction, it is also sufficient to bend only once the leading end portion  3 I (not shown in  FIG. 20 ) of the optical fiber  3 , which is beyond the second front-side bent portion  3 H (not shown in  FIG. 20 ). Therefore, it is possible to reduce the length of the leading end portion  3 I in the front-rear direction, and it is possible to reduce the connector size (see  FIG. 13 ). 
     Moreover, in the first modified example, if the rear-side bent portion  3 F (not shown in  FIG. 20 ) of the optical fiber  3  on the upper side of the parent substrate  20  is wired above the coatings of the six signal lines  5  connected to the rear-side through holes  31 , the optical fiber  3  also becomes less likely to be damaged. 
     In the case where the extra length of the optical fiber  3  is managed by three or more loops within the housing  11  as in the first modified example, it is desirable that only one bent portion is arranged on the front upper side of the parent substrate  20 . In this manner, portions of the optical fiber  3  can avoid being stacked on the upper side of the parent substrate  20  on which the optical coupling portion  43  is present. Also, the optical fiber  3  becomes less likely to move within the housing  11 , and damage to the optical coupling portion  43  can be suppressed. In this case, since the bent portions are stacked on the lower side of the parent substrate  20 , the optical fiber  3  becomes relatively likely to move, but this does not have a significant influence on the optical coupling portion  43  and can be permitted. 
     Second Modified Example 
     Example in which Parent Substrate and Child Substrate are not Separated 
     In the above-described embodiment, the parent substrate and the child substrate are separated from each other, which facilitates the connecting operation and the wiring operation of the optical fiber  3 , the signal lines  5 , and the power supply lines  6 . However, if it is allowable to take time and effort for the connecting operation and the wiring operation, it is not necessary to separate the parent substrate and the child substrate from each other. In the case where the parent substrate and the child substrate are not separated from each other, the photoelectric conversion portion (the light-emitting portion  41  or the light-receiving portion  141 ) is installed on the parent substrate  20  by directly mounting it on the parent substrate  20 . 
       FIG. 21  is a perspective view of the termination portion  12  of the camera-side connector  10  according to the second modified example as seen obliquely from above. As shown in this drawing, in the second modified example, the light-emitting portion  41  serving as a photoelectric conversion portion is mounted on the upper side of the parent substrate  20 , and the optical coupling portion  43  is located on the upper side of the parent substrate  20 . 
     In this second modified example, the optical fiber  3  is also wired so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 . Thus, in the second modified example, portions of the optical fiber  3  can also avoid being stacked on both of the upper side and the lower side of the parent substrate  20 . 
     Moreover, in the second modified example, the direction of the optical fiber  3  in the optical coupling portion  43  is also slanted at an acute angle θ(45° in this example) with respect to the front-rear direction. Thus, in the second modified example, it is also sufficient to bend only once the leading end portion  3 I of the optical fiber  3 , which is beyond the second front-side bent portion  3 H. Therefore, it is possible to reduce the length of the leading end portion  3 I in the front-rear direction, and it is possible to reduce the connector size. 
     Moreover, in the second modified example, the rear-side bent portion  3 F of the optical fiber  3  is also wired above the coatings of the six signal lines  5  connected to the rear-side through holes  31 . Thus, the optical fiber  3  is also less likely to be damaged. 
     In order to realize the second modified example, it is necessary to place a light-emitting face of the VCSEL, which is the light-emitting portion  41 , upward by 450 μm or more with respect to the surface of the parent substrate  20 . For this purpose, a submount (for example, a metallized aluminum nitride substrate) may be placed between the parent substrate  20  and the light-emitting portion  41 . 
     Third Modified Example 
     Example in which Parent Substrate does not Have Recess 
     In the above-described embodiment, the parent substrate has the recess formed thereon, and the optical fiber  3  is wired from the lower side to the upper side of the parent substrate through the recess. However, the parent substrate may not have the recess. 
       FIG. 22  shows the termination portion  112  of the grabber-side connector  110  according to the third modified example as seen obliquely from above. As shown in this drawing, in the third modified example, the recess  124  is not formed on the right edge of the parent substrate  120 . Moreover, in the third modified example, the optical fiber  3  is wired from the lower side to the upper side, passing the outer side of the right edge of the parent substrate  120 . 
     In the third modified example, it is necessary to provide a space that is approximately equal to the diameter of the optical fiber between the inner surface of the housing  111  and the right edge of the parent substrate  120 . For this reason, in the third modified example, the size of the housing  111  is larger than the above-described embodiment. 
     In this third modified example, the optical fiber  3  is also wired so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  120 . Thus, in the third modified example, portions of the optical fiber  3  can also avoid being stacked on both of the upper side and the lower side of the parent substrate  120 . 
     Moreover, in this third modified example, the direction of the optical fiber  3  in the optical coupling portion  143  is also slanted at an acute angle θ( 45 ° in this example) with respect to the front-rear direction. Thus, in the third modified example, it is also sufficient to bend only once the leading end portion  3 I of the optical fiber  3 , which is beyond the second front-side bent portion  3 H. Therefore, it is possible to reduce the length of the leading end portion  3 I in the front-rear direction, and it is possible to reduce the connector size. 
     Moreover, in the third modified example, the rear-side bent portion  3 F of the optical fiber  3  is also wired above the coatings of the six signal lines  5  connected to the rear-side through holes  131 . Thus, the optical fiber  3  is also less likely to be damaged. 
     Fourth Modified Example 
     Example in which Child Substrate does not Have Recessed Portion 
     In the above-described embodiment, the child substrate has the recessed portion formed thereon. However, the child substrate may not have the recessed portion. 
       FIG. 23  is a perspective view of the child substrate  40  of the camera-side connector  10  and its surroundings according to a fourth modified example as seen obliquely from above. As shown in this drawing, in the fourth modified example, the recessed portion  44  is not formed in the child substrate  40 . 
     In the fourth modified example, if the distance between the optical axis of the optical fiber  3  and the surface of the child substrate  40  is shorter than the radius of the optical fiber  3  (including the coating of the secondary-coated optical fiber), it is not possible to reduce the length L′ from the end face of the optical fiber  3  to the coating of the secondary-coated optical fiber. Therefore the optical fiber  3  is more likely to be damaged than in the above-described embodiment. Moreover, in the fourth modified example, it is more difficult to bond the coating of the optical fiber  3  and the child substrate  40  than in the above-described embodiment. 
     In this fourth modified example, the optical fiber  3  is also wired so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 . Thus, in the fourth modified example, portions of the optical fiber  3  can also avoid being stacked on both of the upper side and the lower side of the parent substrate  20 . 
     Moreover, in this fourth modified example, the direction of the optical fiber  3  in the optical coupling portion  43  is also slanted at an acute angle θ(45° in this example) with respect to the front-rear direction. Thus, in the fourth modified example, it is also sufficient to bend only once the leading end portion  3 I of the optical fiber  3 , which is beyond the second front-side bent portion  3 H. Therefore, it is possible to the length of the leading end portion  3 I in the front-rear direction, and it is possible to the connector size. 
     Moreover, in the fourth modified example, the rear-side bent portion  3 F of the optical fiber  3  is also wired above the coatings of the six signal lines  5  connected to the rear-side through holes  31 . Thus, the optical fiber  3  is also less likely to be damaged. 
     Fifth Modified Example 
     Example in which Direction of Optical 
     Fiber in Optical Coupling Portion is not Slanted In the above-described embodiment, the direction of the optical fiber  3  in the optical coupling portion was slanted at 45° with respect to the front-rear direction. However, the direction of the optical fiber  3  in the optical coupling portion may also be parallel to the front-rear direction. 
     In the case where the direction of the optical fiber  3  in the optical coupling portion is parallel to the front-rear direction, it is necessary to bend the optical fiber  3  twice as described in the comparative example using  FIG. 13 . This results in increase of the length of the leading end portion  3 I of the optical fiber  3  in the front-rear direction. Even in this case, if the optical fiber  3  is wired so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 , portions of the optical fiber  3  can avoid being stacked. 
     Moreover, even in this case, if the rear-side bent portion  3 F of the optical fiber  3  is wired above the coatings of the six signal lines  5  connected to the rear-side through holes  31 , the optical fiber  3  becomes less likely to be damaged. 
     Sixth and Seventh Modified Examples 
     Examples in which Rear-Side Bent Portion is Not Located above Coatings of Signal Lines 
     In the above-described embodiment, the rear-side bent portion  3 F of the optical fiber  3  is wired above the coatings of the six signal lines  5  connected to the rear-side through holes. However, the rear-side bent portion  3 F of the optical fiber  3  may not be located above the coatings of the signal lines  5 . 
       FIG. 24  is a perspective view of the child substrate  40  of the camera-side connector  10  and its surroundings according to a sixth modified example as seen obliquely from above. 
     In the sixth modified example, the rear-side bent portion  3 F is arranged above the front-side through holes  32 . Since the end portions of the signal lines  5  are inserted upward into the front-side through holes  32 , there is a possibility that edges of the solder may protrude from the front-side through holes  32 . However, if this arrangement of the rear-side bent portion  3 F is permitted, it also is possible in the sixth modified example to wire the optical fiber  3  so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 . Moreover, if this arrangement of the rear-side bent portion  3 F is permitted, it is also possible in the sixth modified example to set the direction of the optical fiber  3  in the optical coupling portion  43  so as to be slanted at an acute angle with respect to the front-rear direction. 
       FIG. 25  is a perspective view of the child substrate  40  of the camera-side connector  10  and its surroundings according to a seventh modified example as seen obliquely. 
     In the seventh modified example, soldering of the rear-side through holes  31  and soldering of the front-side through holes  32  are both performed in the same direction. Thus, the fourteen signal lines  5  cannot be distributed to two sides of the parent substrate  20 . Moreover, in the seventh modified example, the end portions of the signal lines  5  that are connected to the rear-side through holes  31  are inserted upward into these through holes. Therefore, there is a possibility that edges of the solder may protrude from the rear-side through holes  31 . However, if this arrangement is permitted, it is also possible in the seventh modified example to wire the optical fiber  3  so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate  20 . Moreover, if this arrangement is permitted, it is also possible in the seventh modified example to set the direction of the optical fiber  3  in the optical coupling portion  43  so as to be slanted at an acute angle with respect to the front-rear direction. 
     Reference Example 
     Example in which Bent Portions are not Separated to Two Sides 
     In the above-described embodiment, the optical fiber was wired so that the two bent portions on the front side are separated to the upper side and the lower side of the parent substrate. 
       FIG. 26  is a perspective view of the termination portion  12  of the camera-side connector  10  of a reference example as seen obliquely from above. 
     In the reference example, the extra length of the optical fiber  3  is managed by approximately one loop within the housing  11 . Thus, the optical fiber  3  is routed within the housing  11  so that the orientation thereof in the front-rear direction is changed once. As a result, the optical fiber  3  within the housing  11  has only one bent portion that is bent into a U shape, on the front upper side. That is to say, in this reference example, no bent portion is formed on the lower side of the parent substrate  20 . 
     In this reference example, the direction of the optical fiber  3  in the optical coupling portion  43  (not shown in  FIG. 26 ) is also slanted at an acute angle θ (45° in this example) with respect to the front-rear direction. Thus, in the reference example, it is also sufficient to bend only once the leading end portion  3 I of the optical fiber  3 , which is beyond the second front-side bent portion  3 H. Therefore, it is possible to reduce the length of the leading end portion  3 I in the front-rear direction, and it is possible to reduce the connector size. 
     Others 
     The above-described embodiment is merely for facilitating the understanding of the invention, but is not meant to be interpreted in a manner limiting the scope of the invention. The invention can of course be altered and improved as in the following description, for example, without departing from the gist thereof and includes functional equivalents. 
     Regarding Connector-Equipped Cable  1   
     The above-described connectored cable  1  was configured so as to comply with the Camera Link interface. However, the configuration of the above-described embodiment may also be employed for connectored cable for use in other applications. 
     Regarding Cable 
     Although the above-described composite cable  2  included the signal lines  5  and the power supply lines  6 , the present invention is not limited to this. For example, a cable may be a connectored cable in which connectors are provided on respective end portions of an optical cable without the signal lines  5  and the power supply lines  6 . 
     Moreover, although the above-described composite cable  2  included only one optical fiber, the present invention is not limited to this. For example, a composite cable may include a plurality of optical fibers. 
     LIST OF REFERENCE NUMERALS 
       1  connectored cable,  2  composite cable,  3  optical fiber,  3 A base portion,  3 B lower-side linear portion,  3 C first front-side bent portion,  3 D transition portion,  3 E first upper-side linear portion,  3 F rear-side bent portion,  3 G second upper-side linear portion,  3 H second front-side bent portion,  31  leading end portion,  3 J end face 
       4  differential signal line,  5  signal line,  6  power supply line,  7  stripping portion,  8  caulking member,  10  camera-side connector,  11 ,  111  housing,  11 A,  111 A case,  11 B,  111 B cover,  12 ,  112  termination portion,  20 ,  120  parent substrate,  21  LVDS serializer,  22  camera-side MCU,  24 ,  124  recess,  25  connecting portion,  31 ,  131  rear-side through hole,  31 A rear-side through hole row,  32 ,  132  front-side through hole,  32 A front-side through hole row,  33  through hole for 2-pin header,  34  through hole for 10-pin header,  35  through hole for 4-pin header,  36  through hole for power supply line,  40 ,  140  child substrate,  41  light-emitting portion,  41 A light-emitting face,  42  driving portion,  43 ,  143  optical coupling portion,  44 ,  144  recessed portion,  51 ,  151  protective cover,  52 ,  152  terminal portion,  61 ,  161  2-pin header,  62 ,  162  10-pin header,  63 ,  163  4-pin header,  110  grabber-side connector,  121  LVDS deserializer,  122  grabber-side MCU,  141  light-receiving portion,  142  current-to-voltage converting portion