| 摘要 |
A system for communicating data by modulated beams of infrared radiation uses aligned transmitter and receiver units in which the integrity of data communication is increased compared with single transmitters and receivers by now using two or more transmitters facing two or more receivers, to give increased signal redundancy overcoming the effect of the interruption of a single beam. The output beam divergence from each transmitter may be changed by moving of a lens of desired type along the beam axis, and its direction changed by tilting the transmitter. The output beams may be caused to fall on substantially the same area, in order to increase the integrity of data transmission, or the areas may be caused to overlap each other partially to give rise to an area or areas of chosen shape at specified distances from the transmitter, with the same or different data being receivable at any point in those areas. |
