| 摘要 |
PROBLEM TO BE SOLVED: To perform further highly accurate detection in response to various paper, by enhancing a degree of freedom of a layout, when arranging a means for detecting a residual quantity of roll paper.SOLUTION: The length of the paper up to a contact point to a carrier roller 13 from a pulling-out point of the roll paper 10, is measured based on a height V1 up to a detection point on the paper detected by a distance sensor 20p arranged in a predetermined position of a reference surface (a device bottom surface), a height V2 of the contact point to the carrier roller 13 being a known quantity, a horizontal distance H1 up to the pulling-out point of the roll paper from a sensor detection point and a horizontal distance H2 up to the contact point of the carrier roller 13 from the sensor detection point. A measured value is put in the specific relationship with a winding diameter (a paper residual quantity) of the roll paper 10, and the residual quantity can be acquired from the measured value. This method is high in a degree of freedom of the layout of the sensor detection point, and is effective in detecting the residual quantity close to a paper shortage, and can avoid inconvenience such as printing failure by the paper shortage. |
