Patent ID: 6175419
Filing Date: 2001-01-16
Classification: G01D

Abstract:
A sensor system for determining the position of at least one edge of a web of material traveling along a predetermined travel path, the sensor system comprising:a transmitter assembly disposed substantially adjacent the travel path, the transmitter assembly comprising:a plurality of transmit segments, each of the transmit segments producing a collimated light curtain upon receipt of a light transmit signal, the transmit segments being positioned to transmit the collimated light curtains across only a portion of the travel path, the collimated light curtains being staggered relative to one another; anda controller communicating with the transmit segments to selectively output light transmit signals to the transmit segments to independently control each of the transmit segments;a receiver assembly generating output signals in response to receiving at least a portion of the collimated light curtain transmitted by the transmit segments of the transmitter assembly, the receiver assembly spaced a distance from the transmitter assembly whereby the travel path passes between the transmitter assembly and the receiver assembly and at least a portion of the web of material traveling along the travel path blocks at least a portion of the collimated light curtain from reception by the receiver assembly such that the output signal generated by the receiver assembly indicates the position of the web of material as the web of material is moved along the travel path between the transmitter assembly and the receiver assembly; andwherein the controller receives signals from the receiver assembly indicative of the location of at least one edge of the web of material and selectively controls predetermined transmit segments as the web of material moves laterally relative to the predetermined travel path so that only the actuated transmit segments generally follow at least one edge of the continuous web of material.