| 摘要 |
PURPOSE:To dissipate effectively heat to be generated in a impact dot head, by establishing an electron cooling element near a heat generating source of the head. CONSTITUTION:Heat which is generated by excitation of a magnet coil 7 passes: through two paths such as a route passing an inner peripheral ring 11 and a projection part of a heat transfer member 13 from an outer peripheral surface of the magnet coil 7 and a route in which the heat passes the heat transfer member 13 via a core 1 and a base plate 2 from the inner peripheral surface of the magnet coil 7. The heat is absorbed with a cooling surface of an electron cooling element 15, and is conducted to a radiation plate 17 to be released into air. When current is caused to flow to different metals junction of the electron cooling element 15, one side of the junction absorbs heat and the other side thereof generates heat. Therefore, heat absorbing operation is controlled via a current application terminal 16 by current. In this case, a constant current is always caused to flow to the cooling element 15. For instance, a temperature sensor is attached to near a heat generation source, and a circuit which automatically regulates current to be caused to flow to the cooling elements so that temperature near the temperature sensor becomes always constant is established to perform constant temperature control. Temperature increase of a printing mechanism part of the impact dot head can be effectively restrained by this structure. |
