Patent ID: 8910570

Claim:
A method of determining a registration error in a length-wise direction on a strip of material between a desired location of a pattern applied to the strip of material by a rotary die and an actual location of the pattern applied by the rotary die, the method comprising the steps of: sensing pulses from an encoder corresponding with rotation of the rotary die; incrementing a pulse count each time a pulse from the encoder is sensed if the pulse count is less than a pattern length, wherein the pattern length corresponds to a number of pulses per revolution of the rotary die divided by a quantity of patterns applied to the strip of material per revolution of the rotary die; resetting the pulse count if the pulse count is greater than or equal to the pattern length; sensing a signal from a sensor configured to detect when a fiducial is sensed on the strip of material; determining an actual rotational position of the rotary die based on the pulse count when the fiducial is detected; setting an actual variable to correspond with the actual rotational position; and calculating the registration error based on a difference between the actual variable and a registration target, wherein the pattern is one of a plurality of patterns spaced in even increments around the rotary die such that the quantity of patterns applied to the strip of material per revolution of the rotary die is greater than 1 and the pulse count is reset for each one of the plurality of patterns of the rotary die; wherein the registration target is a value corresponding to a desired rotational position of the pattern, and wherein the registration target is a constant value regardless of which pattern of the plurality of patterns occupies the desired rotational position.