| 摘要 |
PURPOSE:To automatically select an optimum impressing force by providing detecting means for the type of an ink ribbon, energizing means for setting two or more impressing forces to the platen of a print head, and a motor operating the energizing means, and switching the impressing force according to the detected result. CONSTITUTION:The detecting portion provided on the lower part of an ink ribbon cassette is detected to detect the type of an ink ribbon. Then, a cam 3 is rotated by a stepper motor 4 to vary the radius (r) to the outer periphery, thereby varying the energizing force of a coiled spring 2, and two or more impressing forces for contacting a thermal head 1 to a platen 13 opposed to the head 1 are set. With such a construction, the type of the ink ribbon is detected, impressing forces of the head 1 is automatically selected to improve the printing quality. |
