Silicon retina for autofocus

This paper describes a silicon retina that measures image sharpness. The idea is to use this sensor in the image plane of an autofocusing camera system. The chip has 25/spl times/26 pixels, each (60 /spl mu/m)/sup 2/, is fabricated on a (2.2 mm)/sup 2/ 1.2 /spl mu/m CMOS process, and consumes 100 /spl mu/A with 5 V supply.