| 摘要 |
<p>PURPOSE:To reduce the number of parts by using a laser beam having been so far used only for cutting the roll paper concurrently as a light-emitting element for detecting the roll paper size in a roll paper cutting device using the laser beam. CONSTITUTION:When the roll paper 25 is conveyed toward a photosensor 16, a laser beam with a weak output is emitted from a laser light source 21 and also a polyhedron mirror 20 is rotated by a motor 19, and a cutting section 17 is scanned at a high speed at a right angle to the paper conveying direction. When the tip of the roll paper 25 is just passing the cutting section 17, an output is generated from a light receiving element 22 at the portion where the reception of the laser beam has not been blocked by the roll paper 25 among light receiving elements 22..., and the output timing of the laser light source 21 is controlled by a laser power circuit 24 based on its output. Next, when the tip of the roll paper 25 reaches a predetermined position, the output of the laser light source 21 is increased, and the roll paper 25 is cut off by the laser beam.</p> |
