| Autor: |
Guo, Menghan, Chen, Shoushun, Gao, Zhe, Yang, Wenlei, Bartkovjak, Peter, Qin, Qing, Hu, Xiaoqin, Zhou, Dahai, Huang, Qiping, Uchiyama, Masayuki, Kudo, Yoshiharu, Fukuoka, Shimpei, Xu, Chengcheng, Ebihara, Hiroaki, Wang, Xueqing, Jiang, Peiwen, Jiang, Bo, Mu, Bo, Chen, Huan, Yang, Jason, Dai, T. J., Suess, Andreas |
| Zdroj: |
IEEE Journal of Solid-State Circuits; November 2023, Vol. 58 Issue: 11 p2955-2964, 10p |
| Abstrakt: |
We introduce a hybrid 4096 $\times $ 3680 CMOS image sensor (CIS) with an embedded 1032 $\times $ 928 event-based vision sensor (EVS). Within a four-by-four cluster of CIS pixels, one color channel is substituted to provide a photocurrent for an EVS pixel. The EVS readout circuit is allocated on a second wafer and wrapped behind the four-by-four pixel cluster. A third wafer is used to integrate all peripheral readout circuitry for the EVS and CIS functions while achieving a compact sensor footprint. The EVS pixel achieves sub-1 Hz noise rates and 3% contrast non-uniformity (CTNU) at a linear nominal contrast threshold (NCT) of 15%. The row and column readout circuitry bypasses elements without events in a fraction of a clock cycle. Furthermore, a skip function is realized that reads only bordering pixels of a connected set of events. This achieves an event rate of up to 4.6 GEvents/s (GEps). The sensor captures in-pixel time stamps through sampling of a gray code timer realizing a time-to-digital conversion (TDC). Image and event signal processors (ISP & ESP) are integrated on-chip. The ESP provides global ambient and global activity monitoring functions. The sensor supports various flicker mitigation approaches such as adjustment of contrast threshold, in-pixel bandpass filter function and region-of-interest (ROI), and deterministic or random subsampling. The hybrid sensor mitigates challenges in synchronization and parallax error compared with a two-sensor solution using a dedicated CIS and dedicated EVS sensor. Furthermore, only one package and lens are required reducing footprint and cost. |
| Databáze: |
Supplemental Index |
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