| 摘要 |
<p>PURPOSE:To provide a paper feeding control device capable of surely detecting the paper sheet end of a roll paper without being affected by the material of a cylindrical holder etc. and detecting the remaining paper sheet. CONSTITUTION:The light beam passing through the plural slit provided on the disk of the encoder rotating in company with the shaft of the roll paper (not shown in figure) is detected by a photosensor. The angular velocity of the roll paper is calculated basing on the detected period (between slits period). The between slits period (a) immediately preceding the paper sheet end (roll end) is sharply reduced as compared to the between slits period (b), that is, the between slits period at the normal time. Therefore, by providing the lower bound threshold level (c), then on detecting the between slits period falling below the lower bound threshold level (c), it is judged as the paper sheet end.</p> |
