| 摘要 |
PURPOSE: To extend a substantial fixing time in spite of the miniaturization and speed-up of a fixing device and to prevent irregularity in fixing, and offset, etc., due to a high temperatures by providing a plane-line heating element on the upstream side from fixing rollers, and preliminarily heating a toner image. CONSTITUTION: A plane-like heating element 36 installed above a guide 34 and on the upstream side from the nip 28d of the pair of fixing rollers consisting of a heating roller 28b with an infrared ray lamp 28a built in it and a pressure roller 28c, is almost equal in width to the fixing rollers, is so arranged as to be almost parallel to a sheet of paper above the guide 34, and extends near the nip 28d at its one end. Until the sheet of paper with the toner image transferred to it reaches the fixing rollers from the guide 34, the toner image is preliminarily heated by the plane-like heating element 36 which is heated to approximately 150 deg.C, and is inserted into the nip 28d while its uppermost surface is heated to approximately 145 deg.C and its lowermost surface is gradually heated. The heating of the toner image continuous by means of the heating roller 28b, so that the toner image is fixed. |
