1. An imaging system comprising: a light source; means for scanning the light from the light source over an object to be imaged; stationary receiving optics for receiving light reflected from the object to be imaged; a multi-region light detector for detecting light received from the receiving optics, wherein different regions of the object to be imaged are imaged onto different regions of the detector by the receiving optics, and wherein different regions of the light detector can be actuated separately; control means to synchronise the light source scanning and the actuation of the light detector so that a region of the detector imaging the region of the object being illuminated by the light source is actuated; and processing means for measuring the time of flight of light signals from the light source to the actuated portion of the detector for all scanning directions.