Analog integrated circuit for detection of approaching object against moving background based on lower animal vision

A network for displaying target edges without displaying those of the background was proposed based on the insect visual system. The measured results of a test chip fabricated with 1.2 μm CMOS process showed that simple analog circuits constructing the network operate correctly. A test chip of the proposed network was also fabricated with the same process. It was clarified from the measured results that the network can only output signals of target edges. A network for detection of an approaching object, which inputs edge signals, was contained in the fabricated chip. The measured results showed that the chip can detect the approaching velocity and direction and recognize a simple shape such as a circle, square, rectangle and triangle without affecting the background.