In this study, advanced range measurement method using a TOF sensor with 4-tap output pixels and small-duty short light pulse is presented. A CMOS TOF range imager with pinnedphotodiode high-speed charge modulator pixels using lateral electric field (LEF) control has been implemented by a 0.11-μm CIS process with high near infrared sensitivity. In order to improve the range resolution while maintaining the measurable range, multiple time-windows are used for range measurements. Compared with the conventional single time window, the use of N time-windows theoretically improve the range resolution by a factor of N1.5 if the back ground light shot noise is dominant. In the measurement for N=2, the range resolution is improved by a factor of 2.8 compared with the case of N=1 while maintaining the same distance range.
Kohei Yamada, Komazawa Akihito, Taishi Takasawa, Keita Yasutomi, Keiichiro Kagawa, Shoji Kawahito, "A Distance Measurement Method Using A Time-of-Flight CMOS Range Image Sensor with 4-Tap Output Pixels and Multiple Time-Windows" in Proc. IS&T Int’l. Symp. on Electronic Imaging: Image Sensors and Imaging Systems, 2018, pp 326-1 - 326-4, https://doi.org/10.2352/ISSN.2470-1173.2018.11.IMSE-326