MONITOR FOR RIBBON STATE

摘要

PROBLEM TO BE SOLVED: To avoid becoming incapable of reading a printed character with a read sensor by a method wherein printing is not carried out with printed quality deteriorated. ;SOLUTION: A sensor 21 composed of a pair of electrodes arranged by putting an ink ribbon 13 between them, a conversion means converting variation of an electric signal from the sensor 21 to voltage, and a comparator wherein voltage outputted from the conversion means is compared with reference voltage, and the compared result is outputted as a detection signal, are provided. When the ink ribbon 13 is thinned out by repeating printing, the electric signal from the sensor 21 is varied, and voltage outputted from the conversion means is varied. Since a detection signal outputted from the comparator is varied, life of the ink ribbon 13 can be found expired.;COPYRIGHT: (C)1997,JPO