Paper width determination method for a label printer, printing control method for a label printer, and a label printer

摘要

According to the present invention, when a label printer detects or determines the paper width, the paper width detection operation scans the transportation path (A) in the paper width direction by means of a paper width detector (29) not once but twice, and conveys the recording medium transportation distance L, which is longer than the gap length (Lb) of the gap between labels (12c) and is shorter than the label length (La) of each label (12c), between first and second paper width detection operations. Of the two positions detected as the left edge of the recording medium (12a) in the first and second detection operations, the position that is farthest left is used. Likewise, of the two positions detected as the right edge of the recording medium (12a) in the first and second detection operations, the position that is farthest right is used. Alternatively, in each of the paper width detection operations, the point where the reflectivity or the transmittance changes in the scanning range is detected while scanning the area including the paper width of the recording medium (12a). Of the detected points of change in reflectivity, the point of change in reflectivity farthest to the left is used as the position of the left edge of the recording medium (12a), and the point of change in reflectivity farthest to the right is used as the position of the right edge of the recording medium (12a).