| 摘要 |
<p>PURPOSE: To always perform accurate decision of a paper jam, in a device wherein a passing condition of recording paper having various reflection or transmission factors can be supervised. CONSTITUTION: Recording paper 1 having holes 2 arranged in a feed direction with an equal space is set, and when an output is generated from a paper load sensor 5, a CPU 9 controls a roller 4 and a tractor 3 to feed the recording paper 1 by 1 inch. During this time, from a data obtained through sampling by an A/D converter circuit 8 at each feeding 1/360 inch an output of a reflecting photosensor 6 of outputting a voltage value in accordance with reflecting light in a passing point of the hole 2, a threshold value for detecting the recording paper 1 passing is determined, to be stored in a non-volatile memory 12. Hereafter, in the case of feeding the recording paper 1, the determined threshold value is compared with an output of the reflecting photosensor 6, to decide a paper jam. At each setting the recording paper 1 thus fed, a threshold value in accordance with a reflection factor of the recording paper 1 is determined, so that accurate decision of the paper jam can be always performed.</p> |
