Open AccessCMOS image sensor for wide dynamic range feature extraction in machine vision
Author(s) -
Kim HyeonJune
Publication year - 2021
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/ell2.12087
Subject(s) - pixel , cmos , image sensor , dynamic range , feature (linguistics) , artificial intelligence , computer science , feature extraction , dot pitch , wide dynamic range , sensitivity (control systems) , electronic engineering , computer vision , engineering , linguistics , philosophy
This letter presents a wide dynamic range (WDR) feature extraction (FE) readout scheme for machine vision applications using CMOS image sensors (CISs). The proposed scheme with the proposed pixel structure has two operating modes, the normal and WDR modes. In the normal operating mode, the proposed CIS captures a normal image with high sensitivity. In addition, as a unique function, a bi‐level image is obtained for real‐time FE even if a pixel is saturated in strong illumination conditions. Thus, compared to typical CISs for machine vison, the proposed CIS can reveal object features that are blocked by light in real time. In the WDR operating mode, the proposed CIS produces a WDR image with its corresponding bi‐level image. A prototype CIS was fabricated using a standard 0.35‐μm 2P4M CMOS process with a 320 × 240 format (QVGA) with 10‐μm pitch pixels. At 60 fps, the measured power consumption was 5.98 mW at 3.3 V for pixel readout and 2.8 V for readout circuitry. The dynamic range of 73.1 dB was achieved in the WDR operating mode.