| 摘要 |
PURPOSE:To maintain a uniform prining pressure and enable a thermal head to be appropriately brought into contact with and separated from a platen, by pressing a thermal head directly by an elastic member. CONSTITUTION:When printing, a solenoid 38 is turned ON to excite an operating rod 40. The operating rod 40 is drawn in the direction of an arrow (a), and a pressing member 42 is released from a head holder 14. The thermal head 10 is pressed by the elasticity of the elastic member 32 through an upper pressing member 38, is rotated counterclockwise, and is elastically pressed against the platen 12 at a fixed pressure. To separate the head 10 from the platen 12, the solenoid 38 is turned OFF to clear the excitation of the operating rod 40. The operating rod 40 tends to return to an initial position in the direction of an arrow (b), and protrudes, thereby pressing the head holder 14 through the pressing member 42. Since a lower elastic member 48 has an elasticity higher than that of the upper elastic member 32, the pressing member 42 presses the head holder 14 as against the elastic member 32. By this, the thermal head 10 is rotated clockwise against the elastic member 32, is separated from the platen 12, and is positioned with a gap 50 left between the head 10 and the platen 12. |
