| 摘要 |
PURPOSE:To press a thermal recording head against a platen roller under optimum conditions according to the heat generating temperature of the head and make it possible to maintain a constantly fixed recorded density on an image- receiving material, by providing the head with a pressure-adjusting means. CONSTITUTION:A recording head 1 is energized toward a platen roller 2 by a spring 6 provided on the back side thereof, and comprises a group of heat generating elements arranged on the surface thereof on the platen roller 2 side. Between the spring 6 and the head 1 is provided a spring form adjustor 7 formed of a shape memory alloy, the pitch P of which at high temperatures is different from that at low temperatures. The pitch P of the adjustor 7 is varied in correspondence with the temperature of a substrate 8, so that a force for energizing the head 1 toward the platen roller 2 is variably set, and a constantly fixed recorded density can be maintained. |
