Real-time range imaging by phase-stamp method using correlation image sensor

This paper proposes a real-time phase-stamp range finder (PSRF) using a three-phase correlation image sensor (3PCIS). The system consists of the same components as in the conventional light-stripe range finder except the 3PCIS and a three-phase reference signal generator. During a single scan of the sheet beam, the 3PCIS "stamps" the phase of the reference signals at the moment the light stripe is imaged on each pixel. The three-dimensional shape of the object is obtained in real time by converting the detected phase to the angle of the projected sheet beam. Compared to time-stamp VLSI range finders, the proposed PSRF is not affected by spatial nonuniformity in surface reflectance of the object and background illumination. It can be realized with a simpler architecture than the modulation-type PSRF previously proposed by the authors. Experimental results on a developed PSRF system are demonstrated.