Patent ID: 6573923
Filing Date: 2003-06-03
Classification: B41J

Abstract:
A method of tensioning donor sheet in a thermal printer wherein the donor sheet is drawn from a supply roll, interposed between a thermal printhead and a printing sheet and wound on a take-up roll, the method comprising the steps of:providing a take-up motor coupled to the take-up roll for providing a rotational torque to the take-up roll responsive to the energization of the take-up motor; providing a brake coupled to the donor sheet for applying a selected braking force to the donor sheet; reading data characteristic of the donor sheet from a memory element mounted with one of the supply roll and the take-up roll; determining a desired tension to be applied to the donor sheet; determining a radius of at least the take-up roll as a function of at least the data characteristic of the donor sheet read from the memory element; and applying the desired tension to the donor sheet, including the step of selectively energizing the take-up motor as a function of the radius of the take-up roll and the desired tension to be applied to the donor sheet.