| 摘要 |
PURPOSE:To detect whether by printing is required in accordance with the degree of a change in output regardless of detection conditions by providing a relative difference detecting circuit which stores the maximum value and minimum value of a body printing detecting signal which is output from a detector and calculates the relative difference between both values and an acceptability judgement circuit which compares the relative difference with a preentered setting. CONSTITUTION:The body section A1 of a carton A is transported horizontally by drive of a transport belt with a protrusion C. A print pattern (f) and a fold A2 located on the front in a transport direction pass right above a detector 1, and the detector 1 outputs the change of reflective light to an A/D converter 2. After this, the minimum value of a blank section (c), the maximum value of printed characters (d) at the rear and the minimum value of a blank section (e) located at the rear of the rear printed characters (d) are sequentially detected behind the printed characters (b) at the front. If these detections are completed, a relative difference is detected. The relative difference is compared with a setting, and if the difference is higher than the setting, a signal 'printing is required' is output and a program is initialized. |
