| 摘要 |
<P>PROBLEM TO BE SOLVED: To reliably set the effective threshold capable of discriminating presence/absence of a paper sheet to be printed with high accuracy, and to reliably discriminate presence/absence of the paper sheet with high accuracy by using the threshold. <P>SOLUTION: This printer includes a paper sheet detection sensor having a floodlight and a light receiver, and a switch for changing the lighted condition and the extinguished condition of the flood light. A set of the high-level detected voltage in the lighted condition of the flood light and the low-level detected voltage in the extinguished condition of the flood light are acquired. The differential value Vdn is calculated for each of n-sets of the detected voltage. The threshold is calculated by using the mean value and the standard deviation of the plurality of differential values Vdn. After calculating the threshold, presence/absence of the paper sheets to be printed is determined by comparing the newly calculated differential value with the threshold by using the newly acquired high-level detected voltage and low-level detected voltage. <P>COPYRIGHT: (C)2012,JPO&INPIT |
