| 摘要 |
PURPOSE:To realize the economical use of recording paper, by adding the 1st and 2nd patterns and giving an alarm to show that the roll paper comes near its end when a detecting means detects the 2nd pattern. CONSTITUTION:The 1st pattern is previously printed at the final edge of the recording paper 4 along with the 2nd pattern 6 printed at the edge part of the paper 4 respectively. These two patterns have different levels of density. This difference of density is detected by a detecting means 7 consisting of a light source and a cds photodetecting element which is set at the position substantially equal to the recording position of the paper 4 and opposite to each pattern. |
