| 摘要 |
PURPOSE:To increase the durability of a fixing roller, and also to execute a copy of very high quality by detecting the size of a copying form, and controlling the heating value of a heating element in the roller in accordance with a result of its detection. CONSTITUTION:When a copying form 11 of the maximum size passes through between fixing rollers A, B, a lead switch 15 is closed already by a form size detecting signal P, and an AC voltage of a full-wave rectification is applied to halogen lamps 5, 6 serving as heating elements of the fixing rollers A, B. On the other hand, when the machine is switched to a copy by a copying form of small size, the lead switch 15 is opened, and a half wave-rectified voltage is applied to the halogen lamps 5, 6. Accordingly, the heating value of the halogen lamps 5, 6 serving as the heating elements is reduced as a matter of course in comparison with the time when the full-wave-rectified voltage is being applied. |
