A free space optics communication apparatus which can perform stable
communication is disclosed. The free space optics communication apparatus
has a plurality of light-emitting units each emitting a light beam which
forms a generally elliptical irradiation pattern. The plurality of
light-emitting units are set such that irradiation patterns of beams from
at least two of the plurality of light-emitting units partially overlap
at a light-receiving unit of the other apparatus. Further the width of a
combined irradiation pattern formed by combining the light beams is 1.5
times or more larger than a width in a shorter diameter direction of an
irradiation pattern of a light beam from one light-emitting unit.