Thermal printer

A thermal printer for thermally printing information on a recording medium, said printer comprising:

• a platen for guiding the advancement of said recording medium;
• a thermal printhead;
• a carriage mounting thereon said thermal printhead, said carriage being movable along a predetermined path extending in parallel with a longitudinal axis of said platen in a reciprocating manner;
• means for pressing said printhead against said platen while said carriage is moving in a first direction along said predetermined path, in which printing is effected, and keeping said printhead separated away from said platen while moving in a second direction, in which no printing is effected and which is opposite to said first direction along said predetermined path;
• a detachably mountable cassette containing therein heat-sensitive ink ribbon which partly extends outside of said cassette from a supply port to a take-up port defined in said cassette, said cassette being substantially elongated and its longitudinal direction being in parallel with said predetermined path when mounted;
• a ribbon driving mechanism mounted in said printer;
• and advancing means for advancing and controlling feeding of said ribbon from said supply port to said take-up port in association with the motion of said carriage in said second direction, said advancing means being mounted in said cassette and being operatively coupled to the ribbon driving mechanism of said printer when the cassette is mounted in position.