| 摘要 |
A registration control circuit for a printed label cutoff machine controls both the location of the cut by performing a phase adjustment and the length of the individual labels by performing a base speed adjustment. A strip of labels have eyemarks printed thereon for defining the location at which the individual labels are to be cut. An optical scanner is positioned adjacent the labels and generates a scanner pulse upon detection of an eyemark. The control circuit includes a setup control for automatically running the machine into registration from an initial setup position. The setup control functions to generate a reference pulse a predetermined distance before the scanner is expected to see an eyemark. When the eyemark is detected within a designated window area the control utilizes the scanner pulse and the reference pulse to calculate the phase error for each label and generate a phase correction signal proportional to the actual phase error. Individual phase error signals are combined to determine the average phase error which has occurred over the last predetermined number of labels. The average phase error is representative of an average base speed error. If the average phase error exceeds a predetermined threshold, the control will generate a base speed correction signal proportional to the average base speed error. When the eyemark is detected outside the designated window area, the control will attempt to bring the eyemark within the window area by performing a full speed phase adjustment. If, after a predetermined number of consecutive labels, the eyemark has not been moved within the window area, the control will check the base speed and perform a base speed adjustment. The control also includes an alphanumeric display for displaying to an operator, on a prioritized basis, messages indicating the operating status of the machine. |
