Abstract: An optical transmission and receiving module includes a light source; a light receiving element; and a light branching element for causing signal light from the light source to be incident on an optical fiber and causing signal light output from the optical fiber to be incident on the light receiving element. The light branching element includes a prism array including a plurality of triangular prisms arranged at substantially an identical pitch on a plane extending substantially perpendicular to an imaginary line connecting the light source and the light receiving element.

Abstract: A plug-jack type transfer device includes: at least seven electric terminals for connecting a mini single-head electric plug to the transfer device and exchanging an electrical signal therewith; a container body for containing and supporting the electric terminals and receiving the mini single-head electric plug; and a switch mechanism which completes electrical connection between a fourth electric terminal and a sixth electric terminal when the mini single-head electric plug is inserted into the container body. The mini single-head electric plug includes at least seven regions. A region farthest from a plug tip electrode corresponds to a first region.