A Background Light Suppression Method for DToF Image Sensors Based on High‐Efficiency Spatial Coincidence Detection

ABSTRACT In traditional coincidence detection, there are some drawbacks that are long dead time, susceptibility to failure in weak signal scenarios, and high loss rate of effective signal. In this paper, a high‐efficiency spatial coincidence detection architecture is proposed, where refreshable dynamic time window reduces detection dead time and adjacent pixels cooperatively trigger to implement multi‐pixel joint decision, addressing the issue of invalid detection of weak signals. The proposed architecture is designed by 110 nm CMOS process. The simulation results show that the background‐signal‐rate achieves 9.8 dB at 10 m under strong background light of 30 klux, which is 5.3 dB higher than that of the traditional structure. The DToF image sensor with this architecture can realize a maximum detection range of 48 m, with an accuracy of 13.6 cm and a precision of 7.3 cm. The proposed structure improves the DToF ranging performance under strong background light effectively, providing a feasible technical solution for high‐precision 3D imaging.