PURPOSE: To quickly branch data to an optional place in parallel by transmitting the light through a specific pattern mask to change the amplitude transmittance and photoelectrically converting this light.

CONSTITUTION: Two-dimensionally arranged light sources are allowed to emit light by input signals, and the light from light sources is transmitted through a pattern mask 102, which is arranged for one light source and has resolution points whose number is at least square times as large as the number of all light sources, to change the amplitude transmittance, and the intensity of light transmitted through the pattern mask 102 is received by a photodetector, which has resolution points whose number is equal to at least the number of all light sources, and is photoelectrically converted. Thus, input signals are branched to an optional position on the photodetector surface in parallel and independently.