Abstract:
An optical fiber coupling connector of compactness includes a main body, and first and second layers of optical fibers which are all parallel. The main body includes an upper surface, a lower surface, a front surface, and a back surface. The upper surface carries a row of light-emitting optical fibers and the lower surface carries a row of light-receiving optical fibers. The upper surface partially or entirely overlaps the lower surface perpendicularly. The light-emitting fibers are fixed in the upper surface with first glue body and any excess glue flows to and collects by a recess in the upper surface. The light-receiving fibers are fixed in the lower surface with second glue body and any excess glue flows to and collects in a recess in the lower surface.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to communication technologies, and particularly to optical fiber coupling connectors. 
     2. Description of Related Art 
     An optical fiber coupling connector is used in fiber-optic data transmission. The optical fiber coupling connector includes a number of light-emitting modules, a number of light-receiving modules, and a number of optical fibers. Typically, the light-emitting modules and the light-receiving modules are alternately arranged side by side one after the other in a single imaginary line of the optical fiber coupling connector. The optical fibers correspond to the light-emitting modules and the light-receiving modules one-to-one. That is, the optical fibers are arranged side by side one after the other in a single imaginary plane of the optical fiber coupling connector. Some of the optical fibers are optically coupled with the light-emitting modules one-to-one to form a number of first light paths, and the other optical fibers are optically coupled with the light-receiving modules one-to-one to form a number of second light paths. Thus the first and second light paths are alternately arranged side by side one after the other in the single imaginary plane. In order that the optical fiber coupling connector have a large number of first and second light paths to provide high transmission capacity, a large number of the light-emitting modules and a large number of the light-receiving modules need to be arranged along the single line, and a correspondingly large number of optical fibers needs to be arranged side by side one after the other in the single imaginary plane. This requirement increases the overall width of the optical fiber coupling connector, and militates against the need for compactness. 
     Therefore, it is desirable to provide an optical fiber coupling connector, which can overcome or at least alleviate the limitations described. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic, isometric view of an optical fiber coupling connector including a main body, according to an exemplary embodiment. 
         FIG. 2  is a view of the main body only of  FIG. 1 . 
         FIG. 3  is similar to  FIG. 2 , but viewed from another aspect with the main body inverted. 
         FIG. 4  is a cross-sectional view of the optical fiber coupling connector of  FIG. 1 , taken along a line IV-IV thereof. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 and 4  show an optical fiber coupling connector  100  according to an exemplary embodiment. The optical fiber coupling connector  100  includes a main body  10 , four first optical fibers  20 , four second optical fibers  30 , a first glue body  40 , and a second glue body  50 . The optical fiber coupling connector  100  saves space by positioning the group of first optical fibers  20  on top of the group of second optical fibers  30  in a two-layer arrangement. In one embodiment, the first optical fibers  20  provide light-feeding lines (or paths), and the second optical fibers  30  provide light-receiving lines. In another embodiment, the first optical fibers  20  provide light-receiving lines, and the second optical fibers  30  provide light-feeding lines. 
     Referring also to  FIGS. 2 and 3 , the main body  10  is substantially a cuboid. The main body  10  includes an upper surface  11 , a lower surface  12 , a front surface  13 , and a back surface  14 . The upper surface  11  and the lower surface  12  are positioned at opposite sides of the main body  10 , and the upper surface  11  is substantially parallel to the lower surface  12 . The front surface  13  and the back surface  14  are positioned at opposite sides of the main body  10 , and the front surface  13  is substantially parallel to the back surface  14 . The front surface  13  is perpendicularly interconnected between the upper surface  11  and the lower surface  12 , and the back surface  14  is perpendicularly interconnected between the upper surface  11  and the lower surface  12 . 
     The upper surface  11  defines an upper recess  110  and two first receiving recesses  112 . The upper recess  110  passes through the back surface  14 , but does not reach the front surface  13 . The main body  10  further includes a first recessed surface  114  and a first side surface  116  both bordering the upper recess  110 . The first recessed surface  114  is located at the bottom of the upper recess  110 . The first recessed surface  114  defines four first receiving grooves  118  for receiving the four first optical fibers  20 . In this embodiment, each of the four first receiving grooves  118  is substantially semicircular. The first side surface  116  perpendicularly extends from the first recessed surface  114 , and is substantially parallel to the front surface  13 . The first receiving recesses  112  are located at opposite sides of the upper recess  110 , and are symmetrical with each other across the upper recess  110 . Each of the first receiving recesses  112  is in communication with the upper recess  110 . 
     The structure of the lower surface  12  is substantially the same as the structure of the upper surface  11 . In detail, the lower surface  12  defines a lower recess  120  and two second receiving recesses  122 . The lower recess  120  passes through the back surface  14 , but does not reach the front surface  13 . The main body  10  further includes a second recessed surface  124  and a second side surface  126  both bordering the lower recess  120 . The second recessed surface  124  is located at the top of the lower recess  120 . The second recessed surface  124  defines four second receiving grooves  128  for receiving the four second optical fibers  30 . In this embodiment, each of the four second receiving grooves  128  is substantially semicircular. The second side surface  126  perpendicularly extends from the second recessed surface  124 , and is substantially parallel to the front surface  13 . The second receiving recesses  122  are located at opposite sides of the lower recess  120 , and are symmetrical with each other across the lower recess  120 . Each of the second receiving recesses  122  is in communication with the lower recess  120 . 
       FIGS. 2-4  show that the front surface  13  defines two locating holes  130 , four first through holes  132 , and four second through holes  134 . Each of the upper recess  110  and the lower recess  120  is arranged between two alignments defined by the lengths of the two locating holes  130 . The four first through holes  132  are located between the two locating holes  130 . In detail, the first through holes  132  are arranged side by side at equal intervals along a same imaginary first plane  138 , with centers of the first through holes  132  coinciding with the first plane  138 . The four second through holes  134  are also located between the two locating holes  130 . In detail, the second through holes  134  are arranged side by side at equal intervals along a same imaginary second plane  136 , with centers of the second through holes  134  coinciding with the second plane  136 . The first plane  138  is below and substantially parallel to the second plane  136 . The first plane  138  has a width defined by the distance from an outmost long side of an endmost first through hole  132  to an outmost long side of an opposite endmost first through hole  132 . The second plane  136  has a width defined by the distance from an outmost long side of an endmost second through hole  134  to an outmost long side of an opposite endmost second through hole  134 . The second plane  136  partially or entirely overlaps the first plane  138 . In this embodiment, the second plane  136  entirely overlaps the first plane  138 . Thus, the first through holes  132  are aligned with the second through holes  134 , respectively. That is, each second through hole  134  is directly below a corresponding first through hole  132 . 
     The first through holes  132  pass through the first side surface  116  and the front surface  13 , and are in communication with the upper recess  110 . Each of the first through holes  132  includes a first holding portion  132   a , and a first receiving portion  132   b  communicating with the first holding portion  132   a . The first holding portion  132   a  and the first receiving portion  132   b  are arranged in that order from the front surface  13  to the first side surface  116 . In this embodiment, the first holding portion  132   a  is substantially cylindrical, and the first receiving portion  132   b  is substantially in the shape of a truncated cone. The diameter of the first receiving portion  132   b  gradually decreases along a direction from the first side surface  116  to the front surface  13 . 
     The second through holes  134  pass through the second side surface  126  and the front surface  13 , and are in communication with the lower recess  120 . Each of the second through holes  134  includes a second holding portion  134   a , and a second receiving portion  134   b  communicating with the second holding portion  134   a . The second holding portion  134   a  and the second receiving portion  134   b  are arranged in that order from the front surface  13  to the second side surface  126 . In this embodiment, the second holding portion  134   a  is substantially cylindrical, and the second receiving portion  134   b  is substantially in the shape of a truncated cone. The diameter of the second receiving portion  134   b  gradually decreases along a direction from the second side surface  126  to the front surface  13 . 
     Each of the first optical fibers  20  includes a first main portion  22  which is substantially circular in section, and a coaxial first front portion  24 . The first main portion  22  comprises a core portion, and a cladding portion surrounding the core portion. The first front portion  24  comprises the core portion exposed from the cladding portion, and the first front portion  24  has a certain critical length. Each first main portion  22  is received in a corresponding first receiving groove  118 , and each first front portion  24  is inserted in a corresponding first through hole  132  and is held by a corresponding first holding portion  132   a . The first glue body  40  fixes the first optical fibers  20  in the first receiving grooves  118 . 
     Each of the second optical fibers  30  includes a second main portion  32  which is substantially circular in section, and a coaxial second front portion  34 . The second main portion  32  comprises a core portion, and a cladding portion surrounding the core portion. The second front portion  34  comprises the core portion exposed from the cladding portion, and the second front portion  34  has a certain critical length. Each second main portion  32  is received in a corresponding second receiving groove  128 , and each second front portion  34  is inserted in a corresponding second through hole  134  and is held by a corresponding second holding portion  134   a . The second glue body  50  fixes the second optical fibers  30  in the second receiving grooves  128 . 
     When the optical fiber coupling connector  100  is assembled, first, the first main portions  22  are received in the first receiving grooves  118 , and the first front portions  24  are inserted in the first through holes  132  and are held by the first holding portions  132   a . Second, liquid glue is dispensed in the upper recess  110 , to create the first glue body  40  in liquid form surrounding the first main portions  22 . Third, the first glue body  40  is solidified. Fourth, the second main portions  32  are received in the second receiving grooves  128 , and the second front portions  34  are inserted in the second through holes  134  and are held by the second holding portions  134   a . Fifth, liquid glue is dispensed in the lower recess  120 , to create the second glue body  50  in liquid form surrounding the second main portions  32 . Sixth, the second glue body  50  is solidified. During the assembly process, the first receiving portions  132   b  allow easy insertion of the first front portions  24  into the first through holes  132 , and the second receiving portions  134   b  allow easy insertion of the second front portions  34  into the second through holes  134 . In addition, even if the liquid glue corresponding to the first glue body  40  and the liquid glue corresponding to the second glue body  50  is used excessively, the excess of liquid glue corresponding to the first glue body  40  flows harmlessly into the first receiving recesses  112 , and the excess of liquid glue corresponding to the second glue body  50  flows harmlessly into the second receiving recesses  122 . In this embodiment, the liquid glue corresponding to each of the first glue body  40  and the second glue body  50  is ultraviolet (UV) curable adhesive. 
     In the optical fiber coupling connector  100  of a given size, the group of second optical fibers  30  below and parallel to the group of first optical fibers  20  provides a large total number of light paths of the optical fiber coupling connector  100  without unduly increasing the overall width of the optical fiber coupling connector  100 . Therefore, the optical fiber coupling connector  100  can provide high transmission capacity and still be compact. 
     Even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only, and changes may be made in detail, especially in the matters of shape, size, and the arrangement of parts within the principles of the disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.