IMPROVEMENTS IN OR RELATING TO PROCESSING OF TIME-OF-FLIGHT SIGNALS

摘要

PROBLEM TO BE SOLVED: To provide a method and sensor for processing time-of-flight (TOF) signals in a TOF camera system that includes an illumination unit and an image sensor.SOLUTION: The method comprises illuminating a scene with light at a first frequency, detecting light reflected from at least one object in the scene, and determining a phase measurement using I and Q values. The scene is also illuminated with light at a second frequency, the second frequency being 2(n=1, 2,...) of the first frequency, and signs of I and Q values for both the first and second frequencies are used to determine the presence of aliasing in the phase measurement, upon which the phase measurement is corrected. An effective range of the TOF camera system is extended by 2. Relative signal strength needs to be considered in accordance with the reflectivity of objects within the scene, and for a reflectivity of 4% with no aliasing, the ability to detect an object decreases with distance. For an aliased phase measurement for an object with a reflectivity of 100%, the ability to detect the object is substantially constant.SELECTED DRAWING: Figure 6