| 摘要 |
PURPOSE:To enable checking the life of a head at an arbitrary time by means of a simple operation, by a method wherein, when a normal label is printed, check patterns for indicating an upper and a lower limit of a coloring density, simultaneously, are printed by two dot printers to compare them with a normal printing. CONSTITUTION:In addition to an eatable validity date, and a price etc., a bar code 2 is printed on a label 1 issued by a heat sensitive label printer, and check patterns 3 and 4 are printed at both sides of the bar code 2 and at a part, where a printing is ot usually performed, by two print heads usually not used. A head for check pattern is constituted such that its resistance value is adjusted by adjusting a distance between electrodes of a resistance element 5 or changing a part of a width of a resistor, and an upper and a lower limit of a coloring density can be printed individually. Where necessary, the check patterns 3 and 4 are printed to compare them with the density of the bar code 2. |
