Patent ID: 6323948
Filing Date: 2001-11-27
Classification: G01D

Abstract:
A method for guiding a continuous web of material traveling along a predetermined travel path, comprising:providing a transmitter assembly disposed substantially adjacent the travel path so that a collimated light curtain can be transmitted across at least a portion of the travel path;providing a receiver assembly generating output signals in response to receiving at least a portion of the collimated light curtain transmitted by the transmitter assembly, the receiver assembly spaced a distance from the transmitter assembly whereby the travel path passes in between the transmitter assembly and the receiver assembly and at least a portion of the continuous 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 continuous web of material as same is moved along the travel path in between the transmitter assembly and the receiver assembly;activating the transmitter assembly so as to provide at least one collimated light curtain across the travel path;activating the receiver assembly;generating a logical sensor array extending across the receiver assembly;passing the continuous web of material in between the transmitter assembly and the receiver assembly along the predetermined travel path such that the continuous web of material blocks at least a portion of the collimated light curtain from reception by the receiver assembly thereby indicating the position of the continuous web of material therebetween; andgenerating, by the receiver assembly, output signals indicative of the position of at least one edge of the continuous web of material based on the logical sensor array; andcontrolling the lateral position of the continuous web of material to maintain the continuous web of material traveling along the predetermined travel path based on the signals output by the receiver assembly.