PURPOSE: To substantially improve operability by simplifying a beam tracking mechanism by facilitating direction adjustment even when beams are converged narrow, enabling the high quality transmission and long distance transmission of pictures or the like by raising a C/N ratio and surely receiving the beams on the side of a reception part further even when a transmission part and the reception part largely vibrate.
CONSTITUTION: A beam bundle 5 for which the plural beams 4 for the direction adjustment are arranged in a peripheral part and the beam 3 for data is arranged in a center part is generated by the transmission part 1 and is received in the reception part 2 and information in the beam 3 for the data is converted to electric signals. Along with it, the direction of the beam 3 for the data is detected based on the beams 4 for the direction adjustment and is fed back from the side of the reception part 2 to the transmission part 1 and the direction of the beam bundle 5 emitted from the transmission part 1 is controlled.
OYAMADA KIMIYUKI
FURUTA HIROYUKI
