| 摘要 |
PURPOSE:To control a cooling temperature in accordance with an ambient temperature around a heat-generating element by forming a a through hole through which a cooling liquid passes near the heat-generating element of a support member and installing a cooling device capable of making its cooling liquid flow variable in the through hole. CONSTITUTION:A through hole 22a is formed in parallel with a heat-generating element 21 inside an area near the heat-generating element 21 of a heat release plate 22 which supports the heat-generating element 21 of a thermal head. Pipes 26, 27 are connected to both ends of the through hole. The pipe 26 allows a cooling liquid 31 to be discharged into a tank 28, while the pipe 27 supplies the cooling liquid 31 from a pump 30 to the through hole 22a. An operating valve 35 is provided halfway through each branched pipe 33a of a deformed pipe 33 installed between the tank 28 and the pump 30. These operating valves 35 operate sequentially in response to an ambient temperature change around the heat-generating element 21 of the heat release plate 22. The cooling capacity of a cooling device 25 is controlled by increasing the number of the valves 35 which is released in accordance with a temperature increase due to the regeneration of heat in the element 21. Thus an ambient temperature around the heat-generating element 21 of the thermal head can be maintained at constant level. |
