Active Pixel Circuits for CMOS Time-of-Flight Range Image Sensors

摘要

This paper presents a purely CMOS Active Pixel Sensor (APS) capable of time-of-flight (TOF) range imaging. The TOF sensor introduced is used to calculate range in the charge domain. To obtain high speed and highly efficient charge transfer that is important for TOF range imaging, a high gain inverting amplifier and two capacitors connected alternatively to the feedback path are used. The high speed and highly efficient charge transfer using a high gain inverting amplifier in a negative feedback loop enables the TOF range imaging to be based on standard CMOS technology. Moreover, CMOS based amplifier circuits have matured and are relatively easy to design. The analysis of the APS together with simulation results suggests that the proposed technique can achieve a sufficient range resolution of millimeter to centimeter depending on the maximum measured range.