JPS54138447A - Abnormal state detecting device of recording device or the like - Google Patents

Abstract

PURPOSE: To detect abnormality without causing the recording paper to stay in the recording device, by detecting abnormal state by comparing the time of normal passage of recording paper between paper supply and discharge detectors with the time from the start of paper supply till detection of paper supply.

CONSTITUTION: If there is not recording paper even when recording instruction is issued, or if jamming occurs at the supply side, a supply side detector 17 does not detect recording paper. Therefore, an AND gate 22 is opened by the detector 17 and an inverter 21, and the set output of FF 23 by the recording instruction opens an AND gate 26. Accordingly, pulses from the pulse generator 27 are added in an adder 28, and are recorded in a register 28 which is not cleared by the detector 17. This stored content is compared with the value corresponding to the reference time of normal passage of recording paper between supply and discharge detectors 17, 18, which is stored in a register 31, in a coincidence circuit 30. The coincidence signal from the circuit 30 becomes an abnormality signal, so that an abnormality may be detected without holding the recording paper in the recording device.

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