The design of an edge extracting image sensor chip

Limitations in sensor technology, in the context of effective and affordable industrial vision systems, have encouraged the investigation and exploitation of proprietary binary image sensors. Consideration of the unique features offered by the optic DRAM (ODRAM) binary image sensors, together with its inherent disadvantages, stimulated the development of ideas for a novel image sensor to be implemented in custom VLSI. This would take the form of an inherently binary image sensor architecture, which could perform edge detection internally using only neighbourhood electronic operations and parallel optical processing. In order to test and develop these ideas before attempting to commit to silicon, the novel architecture was emulated using the unique properties of ODRAM itself together with special-to-type hardware and software. Subsequently, a full custom implementation of the most promising architecture has been undertaken