Patent ID: 7275876

Claim:
An optical transmission circuit device comprising: a base plate; a plurality of boards arranged perpendicular to the base plate and parallel to each other; and an optical transmission circuit optically connecting the boards, wherein each of said boards has a photoelectric conversion circuit that converts optical signals into electric signals and vice versa; said optical transmission circuit includes a plurality of optical transmission paths parallel to each other and extending in a direction of arrangement of said boards on said base plate, and an optical connection part mounted on said base plate for each of said boards and connected to the optical transmission paths; said photoelectric conversion circuit is connected to said optical connection part so that data transmission between said boards is performed through said optical transmission circuit; said base plate is arranged substantially horizontally and said boards are arranged substantially vertically; other optical transmission circuit devices are located above and under said optical transmission circuit device; each of said boards has a first light-emitting/receiving circuit connected to a respective one of said photoelectric conversion circuits; said optical transmission circuit further includes an optical branch part that chances a direction of transmission of optical signals transmitting through said optical transmission paths to a direction substantially perpendicular to said base plate, a second light-emitting/receiving circuit provided on a bottom surface of said base plate and a plurality of vertical optical transmission paths connecting the second light-emitting/receiving circuit to said optical branch part; said first light-emitting/receiving circuit includes a first electric-to-optical conversion element and a first optical-to-electric conversion element, the first electric-to-optical conversion element sending optical signals to a light-emitting/receiving circuit of another optical transmission circuit device positioned above said optical transmission circuit device, the first electric-to-optical conversion element receiving optical signals from the light-emitting/receiving circuit of said another optical transmission circuit device; and said second light-emitting/receiving circuit includes a second electric-to-optical conversion element and a second optical-to-electric conversion element, the second electric-to-optical conversion element sending optical signals to a light-emitting/receiving circuit of another optical transmission circuit device positioned under said optical transmission circuit device, the second optical-to-electric conversion element receiving optical signals from the light-emitting/receiving circuit of said another optical transmission circuit device.