Patent attributes
A proximity sensing system may include a conductive first trace and a conductive second trace adjacent to, interleaved with, and electrically isolated from the first trace. A density of the traces varies along a first axis such that rates of change of capacitance between the traces associated with movement, through an electric field, of an object in a direction of the first axis at a constant velocity are indicative of the direction. The sensing system may further include a conductive third trace adjacent to, interleaved with, and electrically isolated from the first trace. A first area between the first trace and second trace is independent of and isolated from a second area between the first trace and the third trace. Also, a density of the first and third traces may vary along the first axis.