| 摘要 |
<p>PURPOSE:To operate and stop a recording operation to a recording paper by making the detecting signals of at least two recording paper detectors the signals of ''or'', ''and'' through a logic circuit to judge attachment of dust to the recording paper detector through these signals. CONSTITUTION:Reflection type photosensors 20, 21 are arranged parallel to the width-wise direction of a recording paper 10 at an interval shorter than the width of the recording paper 10 on the bottom of a recording paper receiving box 14. The detecting signals of the photosensors 20, 21 are made ''or'' signal ''and'' signal as judging signals through ''or'' gate 31, ''and'' gate 32 as a judging signal preparing circuit 30 to be sent to a presence-of-recording paper judging and calculating section 40 so that ''or'' signal ''and'' signal are calculated according to a program of a presence-of-recording-paper-dust judging flow chart to judge the presence of dust from the signals of photosensors 20, 21 and the presence of the recording paper 10 when dust is deposited to the photosensors 20, 21.</p> |
