Application of Smart-Pixel and Microlens Arrays to Early Vision

Smart sensors that perform retina-like functions in the analog optical domain using optically cascaded smart-pixel array is being developed for performing operations. It shows that each element of the smart-pixel array has a detector pair laid out with 'doughnut' and 'doughnut-hole' geometries. A microlens forms a demagnified image of a 'neighborhood' of the input pattern on the detector pair, and the smart pixel circuitry produces an optical output that is a function of the contrast between the central region of the neighborhood and the surrounding region. The same general scheme can be used to further process the image formed by the optical outputs of the smart-pixel array. A different computation, such as oriented edge detection, is implemented by appropriately modifying the detector geometries.