Printing apparatus including plural printheads and a pinch roller arrangement

A printing apparatus comprising:

• a paper conveyance path formed between a paper supply unit which supplies paper and a paper discharge port which discharges the paper;
• a paper conveyance mechanism which is provided along the paper conveyance path and has a feed roller and a pinch roller, the feed roller and the pinch roller being provided while facing each other across the paper conveyance path;
• a first thermal head which is located on a first surface side of the paper conveyance path and is provided on a side of the paper discharge port with respect to the feed roller;
• a first platen roller which is arranged to face the first thermal head across the paper conveyance path;
• a second thermal head which is located on a second surface side of the paper conveyance path and is provided between the first thermal head and the feed roller;
• a second platen roller which is arranged to face the second thermal head across the paper conveyance path;
• a pinch-roller contacting and separating mechanism in which the paper is sandwiched between the pinch roller and the feed roller at least when the paper is reversely conveyed;
• and
• a thermal-head contacting and separating mechanism in which the paper is sandwiched between the first thermal head and the first platen roller during printing, wherein a thermal head cam attached to the first thermal head is rotated by a drive motor to control the thermal-head contacting and separating mechanism and a pinch roller cam attached to the pinch roller is rotated by the drive motor to uniquely control the pinch-roller contacting and separating mechanism, and wherein the drive motor transmits power to a first gear that engages a second gear attached to the pinch roller cam and a plurality of gears including a third gear attached to the thermal head cam.