| 摘要 |
PURPOSE:To prevent the wasteful feeding of paper sheet in a printer for hard copy of TV character and pattern broadcasting pictures by a method in which when control signals disappear by any cause, the phenomenon is detected and the feeding of paper sheet is stopped. CONSTITUTION:Set signals Sa are generated by the operation of the print-out button of a printer 2 and AND of picture signals, and put in a set terminal S, S-R latch circuit 3 is set, and printing operation and paper sheet feeding are started through an inverter circuit 4. When printing is ended, control signal, e.g., horizontal synchronous signal, to be sent out with picture signal is processed to generate stop signal Ra, the signal Ra is put in a reset terminal R, the latch circuit 3 is reset, and after the lapse of a given time period, the feeding of paper sheet is stopped. In case where the horizontal synchronous signal disappear during the printing period, the emitter of a transistor 8 becomes ''H'' to reset the latch circuit 3, and thereby printing operation and paper sheet feeding are stopped. |
