Patent ID: 8122798

Claim:
A power cutting tool comprising: a horizontal cutting surface; a moveable blade to cut an object located on the cutting surface, the blade having two lateral sides; a first electrode matrix on the cutting surface and comprising a first array of electrical conductors; a frame spaced vertically apart from and facing the cutting surface and comprising a second electrode matrix comprising a second array of electrical conductors, wherein the frame extends laterally beyond the lateral sides of the blade; a multiplexor connected to the first and second electrode matrices for selectively connecting an electrical conductor of the first and second electrode matrices to an energy source; a controller connected to the multiplexor for controlling the multiplexor such that: in a first mode, vertically-oriented electric fields are generated between the electrical conductors of the first electrode matrix and the electrical conductors of the second electrode matrix; in a second mode, lower horizontally-oriented electric fields are generated between electrical conductors first electrode matrix and upper horizontally-oriented electric fields are generated between the electrical conductor of the second electrode matrix; and wherein the controller automatically switches between the first and second modes; and a detector circuit connected to the first and second electrode matrices for detecting a presence of an object in proximity to the blade.