| 摘要 |
PURPOSE:To obtain a mechanism generating a large pressure contact force with a small drive force by mounting a pressing means, imparting a pressure contact force to a thermal head through a first toggle mechanism, on a support member, and mounting a drive means conducting a thermal head abutting/ separating action through a second toggle mechanism. CONSTITUTION:A worm wheel 11 is rotated counterclockwise by driving a motor 17, whereby a link L17 moves to open an angle theta, a thermal head support board 3 rotates about a shaft 4, and a thermal head 1 is actuated so as to come into pressure contact with a platen 2. Successively, the rotation of the worm wheel 11 brings the thermal head 11 and the platen 2 into an initial pressure contact with each other. Then, the worm wheel 11 is further driven in a direction A, and this drive force acts to open an angle theta2 between the link L17 and a link L29 to rotate a spring plate 18 about a rotating shaft 22 in a direction E through a pin 19. Thereafter, by reversely rotating the motor 17 to reversely rotate the worm wheel 11, the spring plate 18 is reversely rotated until being regulated by a stop plate 23 and brought to a stop. Then, the thermal head 1 rotates so as to separate from the platen 2. |
