light receiving module are mounted on the circuit board and apart from each other the optical coupling lens includes an oblique reflection surface and a recess having a bottom surface parallel to the circuit board two distanced posts perpendicularly extend from the bottom surface and engage with the centers of the protrusions upon assembly to ensure automatic and alignment of the light emitting module with the first converging lens and alignment of the light receiving module with the second converging lens application_number US 201313927151 A description referring to fig1 a photoelectric conversion device 100 according to an exemplary embodiment includes a circuit board 10 a light emitting module 20 a light receiving module 30 and an optical coupling lens 40 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 two protrusions 16 perpendicularly extend from the upper surface 14 in this embodiment the protrusions 16 are cylindrical that is if the protrusions 16 are cut in a plane parallel to the upper surface 14 the.