Patent ID: 7748917

Claim:
A transfer printing apparatus having a tape drive for selectively moving tape past a print head, with the print head operating to transfer material on the tape onto a substrate intended to receive printing, the tape drive comprising: two motors, both of which are stepper motors; two tape spool supports on which spools of tape are mounted, with each spool support being operatively connected to a respective one of the motors, and with the tape extending between the spools and adjacent to the print head; a controller for controlling energization of each of the motors to selectively rotate its respective spool of tape one or more angular steps or to selectively hold its respective spool of tape steady against rotation; with the controller energizing both motors to selectively rotate one of the motors one or more angular steps in a direction of rotation to rotate its respective spool of tape in a tape transport direction for supplying tape in the tape transport direction and to selectively rotate the other motor one or more angular steps in a direction of rotation to rotate its respective spool of tape in the tape transport direction for taking up tape for tape transport, thereby moving tape a predetermined distance in the tape transport direction between the spools and past the print head; a monitor monitoring a parameter indicative of tension in the tape extending between the spools; and with the controller, in response to the monitored parameter indicating that tension in the tape is not at an acceptable level, controlling the operation of the motors to add an amount of tape to the tape extending between said spools to decrease tension in the tape between the spools or to subtract an amount of tape from the tape extending between said spools to increase tension in the tape between the spools so as to correct the tension in the tape between the spools.