| 摘要 |
PURPOSE:To prevent blind hammering action by arranging sensors on both ends of a printing part and permitting printing action of the printing part only when both sensors have detected the existence of paper. CONSTITUTION:If paper P is sent to a printing part 1A side to cover the entire printing part 1A, the light-receiving parts 2B of sensors 2 arranged on both ends of the printing part 1A cannot receive light from corresponding light- emitting parts 2A because of light interruption. Then AND gate 3 accepts this interruption as a logic 1 input, and supplies a signal to such effect that printing is possible to the printing part 1A, interpreting that AND conditions have been satisfied. In response thereto, the printing part 1A commences printing action. If there is any inconvenience on paper P and only light to either of the light- receiving parts 2B is interrupted, AND conditions are not satisfied, and the printing action by the printing part 1A is prevented without fail, and consequently no blind hammering action occurs. |
