Chia-Chi Kuo

This article presents a prototype 4-tap indirect time-of-flight (iToF) CMOS imager with high-speed (HS) range imaging capacity. The sensor features an HS charge modulator, in-pixel memory array, and sub-frame ToF operation, enabling up to 10 Kfps range imaging with eight recording frames and $<$ 1.82% depth noise for 0.3–1.4 m range under HS mode. This sensor also operates in high-precision (HP) mode, achieving $<$ 1.77% depth noise for the 0.4–5.4 m range at 90 frames/s by averaging the subframe signals. With a pixel size of 22.4 $^{H}$ $\times$ 16 $^{V}$ $\mu$ m and 134 $^{H}$ $\times$ 132 $^{V}$ 4-tap pixel array, the sensor successfully demonstrated precise depth imaging under HP mode and clear 3-D imaging for rapid motion objects under HS mode. The potential application of the sensor and future improvements are also discussed.

This article presents a global shutter (GS) high signal-to-noise ratio (SNR) and a high-frame-rate CMOS image sensor (CIS) for in situ fluid concentration distribution measurements using absorption imaging. The pixel consists of a ultraviolet (UV)-visible-near infrared (NIR) waveband pinned photodiode (PD) with high robustness against UV light irradiation for various measurement objects, two-stage lateral overflow integration capacitors (LOFIC) for high dynamic range and high SNR, and a voltage-domain memory bank for GS. The developed prototype CIS with 22.4- $\mu \text{m}$ pitch pixels exhibited 69.7-dB maximum SNR, 123-dB dynamic range, and 1000-frames/s maximum frame rate under single exposure GS and successfully captured images of dynamic movement of NO ₂ gas concentration distribution in the vacuum chamber for 300-mm-diameter wafers.