A CMOS image sensor with charge domain interlace scan

This paper presents the first CMOS image sensor which implements a charge domain interlacing principle to improve the signal-to-noise ratio (SNR) under the same exposure condition (integration time and light intensity). A novel pixel is designed to fit the charge domain interlacing principle, which works in field integration and frame integration mode. This CMOS image sensor also contains a programmable universal image sensor peripheral circuit, thus this sensor can also be used in progressive scan. Comparing the performances of the sensor working in charge domain interlacing and in the progressive scan, the chip measurement results prove that under the same exposure condition, the light response of the charge domain interlacing is the twice that of the progressive scan. The SNR performance can be increased by 6 dB in low light level.