Abstract:
A photoelectric conversion device includes a circuit board, a first light emitting module, a first light receiving module, a second light emitting module, a second light receiving module, and an optical coupling member. The light emitting modules and the light receiving modules are mounted on the circuit board. The optical coupling member includes a first reflective surface obliquely connected to the light incident surface, four converging lenses, a second reflective surface, and a third reflective surface. The converging lenses are formed on the light incident surface. The first reflective surface defines a recess for receiving the second and third reflective surfaces. The third converging lens is fed by the second reflective surface and the fourth converging lens is fed by the third reflective surface.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The present disclosure relates to photoelectric conversion devices. 
         [0003]    2. Description of Related Art 
         [0004]    A photoelectric conversion device includes a circuit board, a light emitting module, a light receiving module, and an optical coupling member. The light emitting module and the light receiving module are mounted on the circuit board. The optical coupling member includes a first converging lens and a second converging lens. The first converging lens is to be aligned with and optically coupled with the light emitting module, and the second converging lens is to be aligned with and optically coupled with the light receiving module. Light emitted from the light emitting module passes through the first converging lens, and light from the second converging lens reaches the light receiving module. The transmission efficiency of light depends on the alignment precision between the first converging lens and the light emitting module and between the second converging lens and the light receiving module. In particular, the higher the precision, the higher is the transmission efficiency. Therefore, it is important to design a photoelectric conversion device having precise alignment between the first converging lens and the light emitting module and between the second converging lens and the light receiving module. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a schematic, isometric view of a photoelectric conversion device, according to an exemplary embodiment. 
           [0006]      FIG. 2  is similar to  FIG. 1 , but viewed from another aspect. 
           [0007]      FIG. 3  is a sectional view of the photoelectric conversion device of  FIG. 1 , taken along the line III-III of  FIG. 1 . 
           [0008]      FIG. 4  is a sectional view of the photoelectric conversion device of  FIG. 2 , taken along the line IV-IV of  FIG. 2 . 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Referring to  FIG. 1 , a photoelectric conversion device  100 , according to an exemplary embodiment, includes a circuit board  10 , a first light emitting module  20 , a first light receiving module  30 , a second light emitting module  40 , a second light receiving module  50 , and an optical coupling member  60 . 
         [0010]    The circuit board  10  includes a lower surface  12  and an upper surface  14 . The lower surface  12  and the upper surface  14  are positioned at opposite sides of the circuit board  10 , and the lower surface  12  is parallel to the upper surface  14 . 
         [0011]    The first light emitting module  20 , the first light receiving module  30 , the second light emitting module  40 , and the second light receiving module  50  are mounted on the upper surface  14  and electrically connected to the circuit board  10 . In detail, the first light emitting module  20 , the second light emitting module  40 , the second light receiving module  50 , and the first light receiving module  30  are arranged in one line, and the second light emitting module  40 , the second light receiving module  50  are located between the first light emitting module  20  and the first light receiving module  30 . That is, centers of the first light emitting module  20 , of the second light emitting module  40 , of the second light receiving module  50 , and of the first light receiving module  30  are arranged in one line. In this embodiment, the first light emitting module  20  and the second light emitting module  30  are vertical cavity surface emitting laser (VCSEL) diodes and are configured for emitting light. The first light receiving module  40  and the second light receiving module  50  are photo diodes and are configured for receiving light. 
         [0012]    Referring to  FIGS. 2-3 , the optical coupling member  60  includes a body portion  61 , a first converging lens  62 , a second converging lens  63 , a third converging lens  64 , a fourth converging lens  65 , a fifth converging lens  66 , a sixth converging lens  67 , a reflection portion  68 , and two supports  69 . 
         [0013]    The body portion  61  is a straight triangular prism and includes a light incident surface  612 , a first reflection surface  614 , and a light output surface  616 . The light incident surface  612  is parallel to the upper surface  14  of the circuit board  10 . The light output surface  616  perpendicularly extends from the light incident surface  612 . The first reflection surface  614  is obliquely interconnected between the light incident surface  612  and the light output surface  616 . In this embodiment, an included angle between the light incident surface  612  and the first reflection surface  614  is about 45 degrees, and an included angle between the light output surface  616  and the first reflection surface  614  is about 45 degrees. A recess  610  is defined in the first reflection surface  614 . The recess  610  includes a bottom surface  611  parallel to the light incident surface  612  and the upper surface  14 . 
         [0014]    The first converging lens  62 , the third converging lens  64 , the fourth converging lens  65 , and the second converging lens  63  are formed on the light incident surface  612  and arranged apart from each other. The first converging lens  62 , the third converging lens  64 , the fourth converging lens  65 , and the second converging lens  63  correspond to the first light emitting module  20 , the second light emitting module  40 , the second light receiving module  50 , and the first light receiving module  30  respectively. The fifth converging lens  66  and the sixth converging lens  67  are formed on the light output surface  616  and arranged apart from each other. 
         [0015]    The reflection portion  68 , which has substantially the same shape as the optical coupling member  60  but in miniature, is positioned in the recess  610  and extends from the bottom surface  611 . The reflection portion  68  includes a second reflection surface  682  and a third reflection surface  684 . The second reflection surface  682  and the third reflection surface  684  are oblique in relation to the bottom surface  611 , and the second reflection  682  is perpendicularly connected to the third reflection surface  684 . In detail, an included angle between the second reflection surface  682  and the bottom surface  611  is about 45 degrees, and an included angle between the third reflection surface  684  and the bottom surface  611  is about 45 degrees. 
         [0016]    The two supports  69  perpendicularly extend from the light incident surface  612  and are arranged apart from each other. In this embodiment, the first converging lens  62 , the third converging lens  64 , the fourth converging lens  65 , the second converging lens  63 , and the two supports  69  are arranged in one line, and the first converging lens  62 , the third converging lens  64 , the fourth converging lens  65 , the second converging lens  63  are located between the two supports  69 . 
         [0017]    The locational relationship between the first converging lens  62  and the third converging lens  64  is substantially the same as that between the first light emitting module  20  and the second light emitting module  40 . The locational relationship between the first converging lens  62  and the fourth converging lens  65  is substantially the same as that between the first light emitting module  20  and the second light receiving module  50 . The locational relationship between the second converging lens  63  and the third converging lens  64  is substantially the same as that between the first light receiving module  30  and the second light emitting module  30 . The locational relationship between the second converging lens  63  and the fourth converging lens  65  is substantially the same as that between the first light receiving module  30  and the second light receiving module  50 . 
         [0018]    In this embodiment, the body portion  61 , the first converging lens  62 , the second converging les  63 , the third converging lens  64 , the fourth converging lens  65 , the fifth converging lens  66 , and the sixth converging lens  67  are formed as a unitary piece. The body portion  61 , the reflection portion  68 , and the two supports  69  are separately formed. In alternative embodiments, the body portion  61 , the first converging lens  62 , the second converging lens  63 , the third converging lens  64 , the fourth converging lens  65 , the fifth converging lens  66 , and the sixth converging lens  67  may be separately formed, and the body portion  61 , the reflection portion  68 , and the two supports  69  are formed as a unitary piece. 
         [0019]    When the photoelectric conversion device  100  is assembled, the optical coupling member  60  is adhered on the upper surface  14  with adhesive. In detail, first, the optical coupling member  60  is placed on the upper surface  14 . In this situation, the two supports  69  abut the upper surface  14 , and the first converging lens  62 , the third converging lens  64 , the fourth converging lens  65 , and the second converging lens  63  are roughly aligned with the first light emitting module  20 , the second light emitting module  40 , the second light receiving module  50 , and the first light receiving module  30 . Second, electrical power is applied to the second light emitting module  40  and the second light receiving module  50  through the circuit board  10 . In this situation, light beams emitted from the second light emitting module  40  enter into the third converging lens  64  and become parallel, and are reflected about 90 degrees toward the third reflection surface  684  by the second reflection surface  682 , and are then reflected about 90 degrees toward the fourth converging lens  65  by the third reflection surface  684 , and finally exit from the light incident surface  612  to reach the second light receiving module  50 . Third, the optical coupling member  60  is adjusted until the intensity of the light beams received by the second light receiving module  50  falls within a predetermined range. In this situation, the second light emitting module  40  is finely aligned with the third converging lens  64 , the second light receiving module  50  is finely aligned with the fourth converging lens  65 , thereby the first light emitting module  20  is finely aligned with the first converging lens  62 , and the first light receiving module  30  is finely aligned with the second converging lens  63 . Fourth, glue is applied to sidewalls of the supports  69  to fix the optical coupling member  60  on the upper surface  14 . Thereby, the photoelectric conversion device  100  has a high alignment precision and a high transmission efficiency of light. 
         [0020]    Referring to  FIGS. 3-4 , when in use, electrical power is applied to the first light emitting module  20  and the first light receiving module  30  through the circuit board  10 , thus light beams emitted from the first light emitting module  20  enter into the first converging lens  62  and become parallel, and are then reflected about 90 degrees toward the fifth converging lens  66  by the first reflection surface  614 , and are finally converged into an external optical fiber (not shown) by the fifth converging lens  66 . Accordingly, parallel light beams passing through the sixth converging lens  67  are reflected about 90 degrees toward the second converging lens  63  by the first reflection surface  614 , and are finally converged into the first light receiving module  30  by the second converging lens  63 . 
         [0021]    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 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.