Advanced Multi-NIR Spectral Image Sensor with Optimized Vision Sensing System and Its Impact on Innovative Applications

Abstract

Innovative applications with multiple near-infrared (multi-NIR) spectral CMOS image sensors (CIS) and camera systems have recently been developed. The multi-NIR filter is an indispensably key technology in practical of using the multi-NIR camera system in consumer camera. Advanced processing technology for multi-NIR signals has been developed using a Fabry-Perot structure. Three types of NIR wavelength filters are formed as a Bayer pattern with 2-x-2μm2 pixel size on a 5-M pixel BSI-CIS. The thickness differences of the three types of bandpass filters are suppressed to less than 75 nm. To enable applications in surveillance, automobiles, and fundus cameras for health management, signal processing technology has also been developed that processes and mixes each signal of a multi-NIR signal with low-intensity visible light images. This provides good image SNR (Signal-to-Noise Ratio) under low lighting conditions of 0.1 lux or less allowing changes of state to be easily identified.