Paper

Variable Dynamic Range CMOS Image Sensor with Area-Efficient LOFIC Pixel and Readout Circuit

2025 Jun

Authors Ai Otani*, Ryotaro Hotta*, Ayaka Banno*, Hiroaki Ogawa*, Ken Miyauchi**, Yuki Morikawa**, Hideki Owada**, Isao Takayanagi** and Shunsuke Okura*

2025 International Image Sensor Workshop (IISW)
https://imagesensors.org/2025-international-image-sensor-workshop/

Single exposure high-dynamic-range (HDR) image sensors have been developed to capture moving objects under extreme illumination conditions. The lateral overflow integration capacitor (LOFIC) pixel structure is considered as one of the solutions. However, a trade-off exists between (1) the dynamic range and signal-to-noise ratio (SNR) at the switching point from high-conversion-gain (HCG) to low-conversiongain (LCG), and (2) the dynamic range and local contrast. This paper introduces an area-efficient LOFIC pixel and a readout circuit that can adjust the dynamic range without requiring additional transistors inside the pixel.