| 摘要 |
PURPOSE:To secure accuracy of printing pitch, by feeding a printing paper forward and backward to remove the slack of the paper. CONSTITUTION:With an auxiliary paper-discharging roller 3 closed, a printing paper 4 is fed forward by 10-50mm. Then, the roller 3 is opened, and the paper 4 is fed backward by reversely rotating a push tractor until the leading end of the paper 4 is passed through a paper detector 12 to be located on the backward side of the roller 3. In this case, the paper 4 is pulled rightward, and a part near the leading end of the paper receives a frictional force exerted by a pressing part 11a of a peper-pressing plate 11. Therefore, the paper 4 is tensioned along a paper guide inner plate 6, whereby the slack of the paper is removed. Next, the roller 3 is closed, and the paper in the slackless condition is fed, and the leading end of the paper in this condition is detected by the paper detector 12. The paper 4 is then fed forward by an amount corresponding to a printed line previously detected in a slack condition, and is fed by an amount corresponding to a printing position for new printing, after which printing is restarted. As a result, printing pitch is maintained at a fixed value. |
