Thermal printer

摘要

A thermal printer (10) has a thermal transfer medium (28) fed past a thermal printhead (21) at a substantially constant velocity by a feed roll (82) engaging the thermal transfer medium just prior to the printhead to maintain a portion of the thermal transfer medium between the printhead and the feed roll relatively stiff. The feed roll is mounted on a cartridge (30) having the thermal transfer medium supplied therefrom. A drag brake (70) is disposed in the feed path of the thermal transfer medium prior to the feed roll to cause a substantially constant premetering tension to be applied to the thermal transfer medium irrespective of the coefficient of friction between the drag brake and the thermal transfer medium. A carrier (14), which supports the printhead and a feed roll driver (90), is driven separately from the feed roll driver so that various ratios between the velocities of the thermal transfer medium and the carrier are obtained to produce various print qualities. One print quality occurs in a draft mode, which is a relatively high speed, in which there is substantial conservation of the thermal transfer medium. The peel angle of the thermal transfer medium from a recording medium (12) on which printing occurs is maintained at a relatively low angle to increase the contact time between the thermal transfer medium and the recording medium.