| 摘要 |
PURPOSE: To prevent a high signal bit transmission rate from decreasing, by allowing each of a plurality of circuit boards to have an edge region for carrying a single or a plurality of light emitting bodies or light receiving bodies, and achieving an optical structure for giving a back plane for cross connection of a circuit board. CONSTITUTION: A rack 2 obtains a framework for accommodating a layered printed circuit board 4. Each circuit board 4 has a block 6 for accommodating a plurality of light-emitting bodies 8 and light-receiving bodies 10 at the rear edge part. An optical back plane 12 is mounted to the rack 2 by a framework member 14, thus carrying a plurality of hologram elements 18. The hologram is arranged so that light from the light-emitting bodies is refracted by one hologram, is reflected to another hologram element from a reflection plane 22, and is inversely refracted to the light-receiving bodies. In this manner by obtaining an optical structure of giving a back plane for cross connection for the circuit 4, the problems caused by an especially high signal bit transmission rate, namely a propagation delay and the like, can be solved. |
