US Patent 10928489 Time of flight camera

A continuous wave time of flight (CW-TOF) camera that modulates sensitivity of its photosensor during an exposure period at a frequency of modulation of structured light that the camera transmits to illuminate a scene that it images but phase shifted relative to phase of the transmitted light by a sampling phase offset modified by a sequence of N perturbation phase shifts λn=2π(n−1)/N, (1≤n≤N), and modifies the structured light in synchrony with the sequence of perturbation phase shifts to reduce error due to multipath interference in determining distances to features in the scene.