| 摘要 |
PURPOSE:To certainly regulate the rotation in a non-taking-up direction and to reduce the number of parts, by bringing a cam into contact with the cam roller integrally rotating along with a take-up reel stand through an energizing means so as to permit the rotation of said reel stand only in a ribbon take-up direction. CONSTITUTION:In a take-up reel stand 8, a cam roller 26 is integrally formed to the upper part of a gear 15 and the cam surface 28a of the cam 28 supported in a rotatable manner by a support shaft 27 is brought into contact with the cam roller 26 and formed into a curve surface gradually increasing in the radius from the center of the rotation of the cam 28. A spring 31 as an energizing means is provided between the pin 29 of the cam 28 and a support shaft 30 and the cam 28 is always brought into contact with the cam roller 26 by the spring 31. Therefore, the take-up reel stand 28 is permitted to rotate only in the take-up direction of an ink ribbon 18 by the cam 28. When a drive motor 13 is reversed in the non-take-up direction, an arm 17 holds a thermal head 21 at a position separated from a platen 2 at a definite interval.
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