OPTICALLY READ OUT SILICON RETINA

OPERATIONS SUCH AS EDGE AND MOTION DETECTION TAX CURRENT AND FUTURE CONVENTIONAL DIGITAL ELECTRONIC IMAGE PROCESSING SYSTEMS. WE PROPOSE A NOVEL INTEGRATED DEVICE CAPABLE OF PERFORMING THESE FUNCTIONS IN REAL TIME. OUR DEVICE IS BASED ON THE "SILICON RETINA" OF CARVER MEAD, BUT ADDS OPTICAL OUTPUTS, ALLOWING PREPROCESSED IMAGES TO BEFED DIRECTLY TO FURTHER OPTICAL PARALLEL PROCESSING STAGES. THESE "RETINAS" ARE CMOS VLSI IMPLEMENTATIONS OF NEURAL NETWORKS WHICH DUPLICATE MANY OF THE FUNCTIONS OF THE VERTEBRATE RETINA. THE TECHNOLOGY WE PROPOSE WILL ALLOW READOUT OF THE RETINA AT FRAME RATES UP TO 10 KHZ, MORE OR LESS INDEPENDENT OF ITS SIZE. IN PHASE I, WE PROPOSE TO BUILD AND DEMONSTRATE A SMALL (32 X 32) PROTOTYPE RETINA WITH BINARY OPTICAL READOUT EMPLOYING INTEGRATED FERROELECTRIC LIQUID CRYSTAL (FLC) LIGHT MODULATORS. IN PHASE II LARGER AND MORE SOPHISTICATED RETINAS WILL BE BUILT, USING ANALOG FLC READOUT. THEN THEY WILL ALSO BE INCORPORATED INTO IMAGE PROCESSING SYSTEMS. THE SUPERIORITY OF THE PROPOSED DEVICE OVER DIGITAL ELECTRONICS,AND ESPECIALLY IT LOW COST, SHOULD GIVE IT MANY COMMERCIAL APPLICATIONS, FOR EXAMPLE IN THE FIELDS OF OPTICAL INSPECTION AND ROBOTICS.