Patent ID: 9604474
Date: 2017-03-28
CPC Classifications: B41J

Claim:
1. A printing unit comprising: a head unit including a thermal head on which a plurality of heating elements are arranged; a platen unit configured to cooperate with the head unit to perform printing on a recording sheet, the platen unit being moveable relative to the head unit between a mounted position in which the platen unit is mounted on the head unit and a released position in which the platen unit is separated from the head unit; the platen unit including a platen frame configured to pivotably support a platen roller and configured to press the recording sheet against the thermal head for printing when the platen unit is in the mounted position; the head unit further including a receiving mechanism configured to receive the platen roller therein when the platen unit is in the mounted position, the receiving mechanism comprising a stopper configured to hold the platen roller in the receiving mechanism; the platen unit further including a subframe loosely connected to the platen frame so that the platen frame is rotatable and shiftable relative to the subframe, wherein the subframe movably supports the platen frame through intermediation of the platen roller; the head unit further including an abutment portion configured to contact the platen frame when the platen unit is in the mounted position; the head unit further including a releasing mechanism on one lateral end side thereof and configured to press the platen frame on the one lateral end side in a direction in which the platen roller leaves the receiving mechanism; and a pressure-applying mechanism connected to the platen frame and the subframe and configured to urge the platen frame on the abutment portion, wherein the pressure-applying mechanism has sufficient strength to keep the platen frame in contact with the abutment portion while the platen roller is leaving the receiving mechanism until the platen roller clears the stopper.