| 摘要 |
PURPOSE:To prevent a ribbon from slacking by a construction wherein a ribbon feed quantity different from that in the face of a small ribbon shift quantity is provided through the detection of a large ribbon shift quantity. CONSTITUTION:When a ribbon shift sensor 10 detects a yellow ribbon slit of a detection plate 8 after detecting a reference slit as the detection plate 8 integral with a ribbon-shifting cam 9 is rotated, it is judged that a ribbon shift quantity is large. Then, a ribbon motor 2 is excited with an advance angle of 0-6pi rad, whereby the motor 2 is rotated clockwise. As a result, a change gear 3 is rotated in the direction of an arrow B, whereby a system in switched from a ribbon-shifting system to a ribbon-feeding system, and since a nail 5 integral with a ribbon gear 4 is fitted in a ribbon take-up hole 21a, a large feed quantity is obtained. On the other hand, in the case of a small ribbon shift quantity, the motor 2 is excited with an advance angle of 0-2pi rad, whereby the ribbon feed quantity is reduced.
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