A 54mm × 54mm – 1.8Megapixel CMOS image sensor for medical imaging

Abstract:: A large area, 54 mm × 54 mm J.8Megapixel CMOS image sensor was designed for scientific applications such as Xray diffraction studies and direct medical X-ray imaging. Both applications have a requirement for large sensing area combined with a high dynamic range. The sensor was manufactured using stitching techniques in order to achieve a large, scalable design. The boundary between stitched sections is seamless, with no lost pixel space. Ten parallel outputs are used to enable a frame rate of up to 20 frames per second with full frame readout. Further increases in speed are possible by defining a region of interest. Multiple reset functionality allows for up to two sub-regions within the image to have a reduced integration time, which can be configured to a proportion of the total frame rate. This effectively extends the dynamic range in applications with images of distinct areas of high intensity light, such as diffraction imaging. The sensor can therefore operate with a basic dynamic range of 67 dB and achieve an effective dynamic range in excess of 135 dB when operated with the multiple resets. Modular design has allowed the fabrication of the sensor in different sizes using the same production masks. Three initial sizes up to 54 mm × 54 mm have been produced and potentially wafer-scale sensors could be manufactured in the same way. © 2008 IEEE.

Authors:: AT Clark, N Guerrini, N Allinson, SE Bohndiek, J Crooks, T Pickering, R Turchetta

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