| 摘要 |
PURPOSE:To retain heat of plural parts in an image forming apparatus, and to compensate the environment in order to retain it proper for each part. CONSTITUTION:When the surrounding temperatures falls to or below a normal temperature, a thermoswitch SM4 is turned on to excite a predetermined relay independent of action or nonaction of the apparatus operated by a copying switch, feeding power to the heater H4 in a photosensitive drum 171 and the heater H5 of a developing device 43, and preventing drop of the discharge effect of a corona discharge current at the time of electrostatic image formation, and drop of development density. When detection temperature rises to or above the normal temperature, the switch SM4 is turned off to stop supply of power to the heater H4 and to feed power by halfwave current through other given relay. When the copying switch is turned on at that state, feed of power to the heater H4 is stopped to cut off current exceeding the necessary quantity, thus permitting plural heat sources to be controlled in accordance with the conditions in different modes, the plural parts in the apparatus to be retained in temperature in necessary extents, and the environments to be compensated to extents suitable for each part. |
