| 摘要 |
PROBLEM TO BE SOLVED: To restrain temperature rise at the paper non-passing parts of a heating member and a pressing member in the case of fixing an image on small size transfer material, and the wrinkles of the transfer material and the breakage of the bearing part of a fixing device caused by the temperature rise of the paper non-passing part. SOLUTION: After finishing the consecutive printing of envelopes (S2), a next printing signal and a paper size designating signal are received (S3), and t' is decided according to the paper size in STEP 3 (S4). Decision of t' is made so that t'=ΔT in the case of (the width of the previous printing transfer material)>=(the width of the next printing transfer material), and t'=20 in the case of (the width of the previous printing transfer material)<(the width of the next printing transfer material). After finishing the preparation of image forming, a temperature difference ΔT between a paper passing part and the paper non-passing part on the surface of the heating roller is detected by temperature detection elements 113 and 120 (S7). Only when the width of the next printing transfer material is wide and ΔT>20[ deg.C], requirement on next printing image data is stopped, and when ΔT<=20[ deg.C] is attained, the image data are required (S9) and printing is started (S10). |
