| 摘要 |
PURPOSE:To prevent the scratch of printings as well as damage to a printing hammer, etc., by a method in which the anomaly of an ink ribbon is detected in early period by counting the number of printed lines with respect to the wearing degree of the ink ribbon regardless of the making and breaking of input power source. CONSTITUTION:Signals 20 sent out of a control section 1 every one line-printing are put in a counter 2 which sends out a count-over signal 3 every 100-counting. The signal 3 is put in a presetting type counter 5 through a gate 4. In the presetting type counter 5, values corresponding to printed line numbers enough to withstand an ink ribbon are set, and the count values are kept by the gate 4 regardless of the making and breaking of the power cource. When the count values come to coincide with preset values, a ribbon alarm check signal is sent to a switch box 7 consisting of a switch 8 and a light source 9, and the light of the light source 9 is detected by a photo cell to putout the ribbon alarm signal. |
