Patent ID: 7001089

Claim:
A thermal printer comprising: a main body frame having a bearing portion; a platen roller having a shaft rotatably and detachably supported by the bearing portion of the main body frame; a support member mounted on the main body frame for undergoing movement; a thermal head supported by the support member for movement into and out of pressure contact with the platen roller for recording printing data on a recording medium disposed between the thermal head and the platen roller; biasing means for biasing the thermal head into pressure contact with the platen roller; a load detectiontype sensor mounted on the main body frame for contacting the platen roller via the recording medium to detect a preselected state of the thermal printer in which the shaft of the platen roller is supported by the bearing portion and in which the recording medium is disposed between the thermal head and the platen roller; and moving means for releasing the shaft of the platen roller from the bearing portion of the main body frame by moving the shaft of the platen roller in a direction in which the shaft is separated from the load detection-type sensor, the moving means comprising a cam abutted against the support member and a lever for pivotally moving the cam to move the support member in a direction in which the support member is separated from the platen roller.