| 摘要 |
PURPOSE:To prevent nonuiformity of density or voids from being generated in printed images, by a construction wherein a thermal head is biased to one side relative to a support shaft by a spring force or the like, and can be moved according to the thickness of a recording medium. CONSTITUTION:A thermal head 1 is biased in the direction of an arrow G relative to a support shaft 3 by a leaf spring 7, and when it is pushed in the direction of an arrow F by a pushing-type solenoid 8 and a coil spring 9 arranged on the peripheral surface thereof, the head 1 is pressed against the peripheral surface of a platen roller 4 with a pressure. A heat generating element row 2 is provided on a surface of the head 1 brought into contact with the platen roller 4, and performs desired printing on a recording medium 5, 5' disposed between the head 1 and the platen roller 4. By the construction wherein the thermal head 1 capable of being rotated relative to the support shaft 3 is biased to one side relative to the shaft 3 by the force of the spring 7 and the like so that it can be moved according to the thickness of a recording medium, favorable printing quality free of nonuniformity of density, voids in printed images, wrinkling of an ink ribbon or the like can be realized on the recording medium 5, 5', irrespective of the thickness of the recording medium. |
