| 摘要 |
PURPOSE:To prevent the temperature of a resistance heating element from excessively rising and to detect the temperature of the resistance heating element at a high speed and with high accuracy by detecting the temperature of the resistance heating element as the fixing heat source of toner having a heating and fusing property. CONSTITUTION:Since a resistor 32 whose coefficient of resistivity is high such as tungsten or molybdenum is laminated and printed on the back surface of an insulating substrate 7 such as alumina ceramic whose heat resistance is high, the temperature of the resistance heating element can be detected at a high speed and with high accuracy by executing such control that the resistance heating element is energized and heated when a current value flowing to the resistor 32 is high and the energizing of the resistance heating element is stopped when the current value flowing to the resistor 32 is low by utilizing the temperature characteristic of the resistor 32 that a resistance value is small and a large current flows at the time of low temperature and the resistance value is large and the current hardly flows at the time of high temperature. |
