Very Large Area CMOS Active-Pixel Sensor for Digital Radiography

To address the growing demand for low-noise large-area digital-radiography sensors, a unique CMOS active-pixel sensor (APS) technology has been developed. Large-tiled CMOS radiographic panels can compete in performance with passive-pixel arrays, amorphous-silicon thin-film-transistor panels, and phosphor-panel technologies. Although CMOS sensors have become a key technology in low-cost consumer camera products, CMOS APS technology is also suited for manufacture of large-format imagers used to construct radiographic-detector panels. Large-area CMOS radiographic sensors combine a large full well over 3.5 million e- with low read noise less than 300 e- to provide wide dynamic range and improved signal-to-noise ratio under demanding radiographic imaging conditions. With precision-assembly techniques, tiling gaps are minimized to be less than 0.3 pixels to produce fully correctable flat-field images. Applications include nondestructive testing, scientific imaging, security screening, and medical radiography.