| 摘要 |
PURPOSE:To prevent dirt from being adhered to the head of each printing line, by setting the outer diameter of a take-up roller in an ink ribbon cassette and that of a timing pulley in a fixed ratio. CONSTITUTION:The diameter d2 of the take-up roller 7 is so set that 1.5d1<=d2, where d1 is the diameter of the timing pulley 31. Though the velocity V1 of the carriage 1 is constant irrespectively of the quantity of an ink ribbon 5 taken up by the take-up roller 7, the line speed V2 of the ribbon 5 is increased with the take-up quantity, and sag of the ribbon 5 as in the initial state is reduced. Therefore, the above setting means such a setting that the line speed V2 of the take-up roller 7 and the velocity V1 of the carriage 11 satisfy the relationship 1.5V1<=V2. Accordingly, even when thermal transfer recording is started in the initial state, the ink ribbon 5 does not sag, and adhesion of dirt S can be prevented from occurring. |
