| 摘要 |
PURPOSE:To detect any defect in the movement of a printing head and thereby prevent misalignment of a printing start position and loss of printing data by allowing a printing head to shuttle back and forth several times when power is turned ON and comparing this return movement distance with a distance across both ends of a position for setting printing paper. CONSTITUTION:If printing paper has no defect, a printing head 10 travels from an initial position (a) to a left reference point position (b) to perform a line feed action. After this, the printing head 10 is initialized to move to a right reference point position (c). At that time, an encoder input circuit 6 counts the number of pulses from the position (b) of the printing head 10 to the position (c), and determines whether this number of pulses equals to a specified standard value M between the positions (b, c) The matching of the pulse frequency count value with the standard value M is determined and the printing is normally completed. If any failure occurs due to paper at a position A of a guide 15 while the printing head 10 moves, the printing head 10 is reversed in its feed direction at a position (e), and the encoder input circuit 6 judges that the count value of pulses from the position (e) of the printing head 10 to the position (c) does not reach the standard value M. Then the counting of the number of pulses between the position (c) and the position (b) is resumed. |
