Patent ID: 8111274
Filing Date: 2012-02-07
Classification: B41J

Abstract:
1. A thermal printer, comprising: a main body frame having two opposed notches; a thermal head swingably mounted to the main body frame; a platen roller disposed so as to be opposed to a printing surface of the thermal head for sandwiching thermal paper with the thermal head to feed the thermal paper; a lock arm that is swingably mounted to a supporting shaft mounted to the main body frame and that presses shaft bearings rotatably supporting the platen roller to a thermal head side to lock the platen roller with the notches of the main body frame, first springs for biasing the platen roller supported by the lock arm to the thermal head side; and second springs for biasing the thermal head in the platen roller direction, wherein the lock arm is provided, on a tip end portion thereof, with a first inclined surface which, when the platen roller and the shaft bearings are moved toward openings of the notches, comes into contact with an outer peripheral surface of each of the shaft bearings and generates a force in a direction of closing the lock arm, the first springs and the second springs are arranged so that their directions of biasing are parallel, and the first springs are disposed closer to the supporting shaft than the second springs and the first inclined surface of the lock arm.