| 摘要 |
PURPOSE:To improve the durability of a thermal head by a method wherein a platen roller is made movable upwards from a home position by a predetermined distance and energized by a spring force so as to be fastened on the home position. CONSTITUTION:Pins 46, 48 projected from a vertical wall surface on both ends of a head holder 44 are slidably nested into slits 50, 52 provided through a flat plate 30c of a support frame 30 and a bracket 32 and pressed upwards by head pressurizing springs 54, 56. Then, during a non-recording time, a thermal head 42 is held lowered by a predetermined distance by an attracting force of a solenoid 40 against the resiliency of the springs 54, 56. During a recording time, the solenoid 40 is de-excited, the head holder 44 is projected upwards by a predetermined amount by the resiliency of the springs 54, 56, and the upper surface of the thermal head 42 comes into collision with the surface of a platen roller 12 and resiliently abuts thereto. At this time, side frames 6, 8 absorb the impact by rotating clockwise about a shaft body 4 due to the impact from the head 42. Therefore, the durability of the thermal head can be enhanced. |
