| 摘要 |
PURPOSE:To enable the relative positional relationship between a printing paper surface and a carriage to be accurately followed up, by a method wherein the quantity and the direction of rotation of a platen are detected when the platen is mannually rotated, in a printer in which the feed of a printing paper is controlled through the rotation of a platen. CONSTITUTION:At the time of a normal line shift, a paper-feeding motor 7 is driven in accordance with a depression of a line shift key such as a carriage return key, whereby the platen 1 is rotated in the direction of an arrow A or an arrow B to control the relative positional relationship between the printing paper surface and the carriage. On the other hand, when the operator manually rotates the platen by rotating a platen knob 6, the quantity and the direction of rotation of a ring 8 which is rotated as one body with the platen 1 are detected by an optic sensor. A microprocessor counts detection signals, adds the count value to or subtracts the count value from the amount by which the platen 1 has been moved at the time of key operations, renews recording information on the relative positional relationship between the printing paper surface and the carriage, and accurately controls the paper feed quantity. |
