| 摘要 |
PURPOSE:To easily detect an abnormal movement of a printing head with respect to each dot, and correcting the movement of the printing head to thereby prevent erroneous printing from occurring, by comparing a pulse from a pulse generating means with an output from a means for delaying the mentioned pulse by a predetermined period of time. CONSTITUTION:A timing pulse of a predetermined periodicity is generated with respect to each dot by a timing pulse generation circuit 7 so as to be supplied to a delay circuit 8, a timing counter 11, and AND-gates 12, 13. An output from the delay circuit 8 is input into a delay circuit 9 and AND-gate 12, and an output from the delay circuit 9 into the AND-gate 13. In the delay circuits 8, 9, the timing pulse is delayed by a predetermined period of time respect to its timing interval. When the printing head is abnormally moved, an irregular pulse and a delayed pulse are compared with each other in the ANd gate 12, and a fault signal generating circuit 10 is energized through an OR gate. |
