Improving image sensors used in digital cameras
Digital cameras owe much of their popularity and effectiveness to complementary metal-oxide semiconductor (CMOS) image sensors that are built into them. Despite all the recent advancements, digital cameras are still plagued by image quality, colour discrimination, restricted dynamic range and power issues. With EU funding, the EDISON-GA (European doctorate in image sensors with optical nanotechnology at Glasgow and Awaiba) project is training young researchers in the design of image sensors through the use of optical nanotechnology. Overall, the aim is to advance knowledge leading to novel image sensors. This will result in cost-efficient cameras for commercial and medical use with a much wider dynamic range that provide better colours and X-ray detection. During the first year, the project recruited five doctoral researchers with expertise in nanofabrication, chip design and biomedical applications. Joint research during this time has already contributed to the development of two sets of cameras for optimised colour and X-ray imaging. The team created a new design for colour filters to be used in CMOS image sensors. This filter design will enable digital cameras to better separate red, blue and green colours. It also developed a design to enhance the low light performance of CMOS pixels. Project partners came up with an innovative way to perform compressed sensing, a promising new method for image sensing. Specialised CMOS pixels and low-cost image sensors for very-high-intensity radiation have also been designed. A radiotherapy image sensor prototype is currently under development. Ongoing research in CMOS image sensors will enable EDISON-GA to introduce optimised solutions for digital and biomedical cameras. Both the general public and medical community stand to benefit.
Keywords
Image sensors, digital cameras, complementary metal-oxide semiconductor, optical nanotechnology