METHOD OF ASCERTAINING THE CORRECT LOADING OF A PAPER OR LABEL ROLL IN A THERMAL PRINTER

A method for detecting when a thermal paper roll (1), in particular a linerless label roll (1), has been loaded incorrectly in a thermal printer includes the following steps: - Step 1: The print head (3) is activated to print a test mark (17) on the thermal paper ribbon (9). - Step 2: The paper transport roller (6) is activated to transport the paper ribbon (9) in reverse direction by a predetermined first distance as required to bring the test mark (17) back to the paper-end detector (2). - Decision: If the test mark (17) is detected by the paper-end detector (2) the method continues at step 3; if no test mark (17) is detected the method continues at step 4. - Step 3: The paper transport roller (6) is activated to transport the paper ribbon (9) in forward direction by a predetermined second distance as required to advance the test mark (17) past the cutter device (4, 5); the cutter device (4, 5) is activated to cut off the overhanging end of the paper ribbon (9); the printer is ready to operate. - Step 4: The printer is blocked against further operation until the paper roll (1) is repositioned correctly in the roll cage (14).