System and method for CMOS image sensing

摘要

A system is provided for determining a color using a CMOS image sensor. The system includes an input port for receiving a user command. The system further includes an image sensor, an optical device that forms an image on the image sensor, and a processor. The image sensor includes an n-type substrate and a p-type epitaxy layer overlying the n-type substrate. The image sensor includes a control circuit that applies a first voltage on the n-type substrate to obtain a first output. The control circuit applies a second voltage on the n-type substrate to obtain a second output. The control circuit also applies a third voltage on the n-type substrate to obtain a third output. The p-type epitaxy layer includes a silicon germanium material. The image sensor additionally includes an epitaxy layer interposed between the n-type substrate and the p-type epitaxy layer.