A receiving apparatus and transmitting apparatus capable of transmitting
and receiving a high speed optical signal and a communication system
using the same, including a transmitting apparatus having a conversion
circuit for converting serially input data to a plurality of bits of
parallel data given predetermined information and an LED array having a
number of LED units corresponding to the number of bits of the parallel
data from the conversion circuit arranged in an array, wherein the LED
units are controlled in light emission in parallel based on bit
information of corresponding parallel data to emit optical information
signals dispersed in a spatially predetermined range, and of a receiving
apparatus having a plurality of photo-diodes arranged in an array for
emitting electric signals of levels in accordance with amounts of light
received, wherein the photo-diodes output electric signals in parallel.