Patent ID: 6635895
Filing Date: 2003-10-21
Classification: B65H

Abstract:
A sensor system for determining the position of an edge of a moving web of material traveling along a predetermined travel path, the web of material having a first side, an opposed second side and at least one edge, the sensor system comprising:a transmitter/receiver assembly positionable adjacent to the travel path of the moving web of material, the transmitter/receiver assembly comprising: a transmitter transmitting a light curtain across at least a portion of the travel path; and a receiver receiving a shifted light curtain transmitted across at least a portion of the travel path and generating video output signals indicative of the position of the edge of the moving web of material; a beam reflector assembly positionable adjacent to the travel path of the moving web of material such that the travel path passes between the transmitter/receiver assembly and the beam reflector assembly, the beam reflector assembly receiving an unblocked portion of the light curtain, shifting the unblocked portion of the light curtain a distance laterally to form the shifted light curtain, and transmitting the shifted light curtain across the travel path of the moving web of material; and a sensor signal processing receiving the video output signals and processing the video output signals to determine the location of the edge of the web of material.