Improvements relating to optical sensing systems.

摘要

An optical sensing system comprises a single continuous wave light source (1), a series of phase shifting switching devices (6) arranged to receive light from said light source (1) and driving means (4) individually associated with the phase shifting switching devices (6) for driving said devices (6) with pulses at different frequencies whereby each device (6) produces output pulses of different frequencies in different deflected directions. The devices (6) are sequentially operated so that the light from the continuous wave light source (1) passes straight through a first device (6) to a second device (6) when the first device (6) has produced its light output and is no longer being driven by the driving means (4) individual to it whereupon the second device (6) will be driven to generate output pulses after which the second device (6) ceases to be driven and allows the light from the continuous wave light source (1) to pass through both the first and second devices (6) to a third device (6) and so on until the last device has produced output pulses whereupon the first device will be re-operated for the generation of pulses.