| 摘要 |
PURPOSE:To provide the titled device which automatically detects an abnormal printing such as drum prints, missing prints, by a method wherein, based on a detecting output of a drum-in detector and a synchronizing pulse of a generator, a relation between an operation condition and a timing is detected. CONSTITUTION:Flip flop circuits FF1 and FF2 produce an output (f) and an inversion output (h) by a reset priority. A differential pulse (i) synchronizing with a rear edge of a synchronizing pulse (c), an output (f) and an inversion output (h) are provided to a gate G3, a coincidence thereamong generates a signal (j) indicating an abnormal printing. A point of time when a paper detector PPD detects a paper coincides with an output of a shift registor SR and a differential pulse (i), a missing print signal Sr is sent out from a gate G5. If a point of time when the paper detector PPD does not detects a paper coincides with the output of the shift registor SR and the differential pulse (i), a drum print signal Sd is sent out from the gate G4. |
