CONTROL METHOD FOR ROTATARY SPEED OF PLATEN ROLLER AS RECORDING PAPER WIDTH AND THERMAL PRINTER USING THE SAME

PURPOSE: A method for controlling the rotation speed of a platen roller depending on the width of a recording sheet and a thermal printer using the same are provided to minimize the friction generated at the contact point of the thermal head and a platen roller, thereby reducing the miss feeding of a recording sheet. CONSTITUTION: A method for controlling the rotation speed of a platen roller depending on the width of a recording sheet and a thermal printer using the same include a case, a platen roller (200), a thermal head (300), a sensing unit, and a control unit. The case has an accommodation space in which a recording sheet is accommodated therein. The platen roller has a fixed width and transfers a recording sheet (P) by coupled in the case to be rotatable. The thermal head is arranged adjacent to the platen roller so that the recording sheet passes between the platen roller and the thermal head, is provided to be slidable so as to be pressured in the platen roller direction, and generates heat from one surface thereof. The sensing unit is provided on the route that the recording sheet is transferred in the platen roller direction so as to be biased on one side based on the center line with respect to the width direction of the recording sheet, and senses whether a sleeping zone (Z) which is generated by the absence of the recording sheet at the outside of the width direction is present or not between the platen roller and the thermal head. The control unit reduces the rotation speed of the platen roller to be less than the reference speed according to whether the recording sheet is present or not in the sleeping zone.