Tape drive and printing apparatus

A thermal transfer printer for selectively transferring a meltable ink material carried on a tape to a substrate intended to receive ink for printing, the printer comprising:

• two spool supports on which two spools of tape carrying meltable ink material may be mounted for rotation, with the tape being wound on the spools and with a span of tape being held in tension between the spools;
• a print head positioned adjacent to the span of tape between the tape spools, the print head comprising heating elements selectively energized for transferring meltable ink material on the tape to the substrate when the heating elements are energized and moved into contact with the tape, with the tape in contact with the substrate;
• a print head drive selectively moving the print head between an extended position adjacent the span of tape and a retracted position spaced apart from the span of tape;
• a monitor monitoring a parameter indicative of tension in the tape extending between the spools;
• a tape drive comprising two electrically energizeable spool drives, one for each spool support, with each spool drive being selectively operable when energized to rotate its respective spool of tape to a commanded angular position and then to selectively hold the spool of tape at the commanded angular position against tension in the tape extending between the spools;
• the tape drive further comprising a controller controlling energization of one of the spool drives to rotate its respective spool of tape in a tape transport direction for supplying tape in a tape transport direction past the print head and controlling energization of the other spool drive to rotate its respective spool of tape in the tape transport direction for taking up tape for transporting tape between the spools of tape;
• the controller controlling energization of each of the spool drives to rotate its respective spool of tape to a commanded angular position to transport the tape a predetermined distance in the tape transport direction between the spools of tape and past the print head to position a second region of tape, from which meltable ink material is to be transferred and that is adjacent to a first region of tape from which at least some of the meltable ink material has been previously transferred, at the print head for transferring at least some of the meltable ink material from the second region of tape to the substrate;
• the controller, in response to the monitored parameter indicating that tension in the tape is not at an acceptable level, controlling the energization of said spool drives to add an amount of tape to the span of tape extending between the spools to decrease tension in the span of tape extending between the spools or to subtract an amount of tape from the span of tape extending between the spools to increase tension in the tape extending between the spools for adjusting the tension in the span of tape extending between the spools;
• the controller further controlling the print head drive to move the print head to its extended position adjacent to the span of tape between the spools for transferring meltable ink material on the span of tape between the spools to the substrate;
• and
• the controller further controlling energization of the heating elements on the print head to be heated in a predetermined sequence for transferring meltable ink material from the second region of the tape to the substrate for printing onto the substrate.