| 摘要 |
<p>PURPOSE:To print always normally by a method wherein printing of a deterioration generated dot is recognized by detecting variation in a resistant value of a resistor unit of a dot of a printing head, and printing is performed with dots other than deterioration generated dots. CONSTITUTION:In consignment from a work, voltage is applied to each resistor 31, 32, 33, 34 of a resistor unit 3 from a printing driver 2 to a printing head 1. A voltage value of each resistor is read by switching successively switches 41, 42 by the same timing, is varied to a digital value with an A/D converter 6, and is stored in a non-volatile memory as an initial value. Besides, voltage is applied to the printing head 1 from the printing driver 2 when neither voltage nor current are applied to the printing head 1 for a specified time in printing, and the voltage value of each resistor 31, 32, 33, 34 is measured. This measured value is compared with the initial value of the non-voltage memory by a comparator to perform judgement. Deterioration of a dot of the printing head 1 is judged by this result, which is communicated to firmware. The firmware performs printing of a deterioration generated position of the printing head. Always normal printed results can be obtained thereby.</p> |
