| 摘要 |
<P>PROBLEM TO BE SOLVED: To deal with a shock jitter by switching the rotating speed of a registration roller in accordance with the expansion of the diameter of the registration roller in the case of continuously letting sheets through on both-sided printing. <P>SOLUTION: A constitution satisfying a relation of (Vtc+Vth)=(2Lp-Lmin-Lmax)/Tr is adopted (Lp: length of sheet, Vtc: sheet conveying speed just after the start of a fixing part, Vth: sheet conveying speed after the prescribed number of sheets are continuously let through, Lmin: the shortest conveying distance when the sheet is conveyed between a transfer part and the fixing part, Lmax: the longest conveying distance in the aforesaid state, and Tr: a time until the trailing end of the sheet reaches a transfer nip at a prescribed printing speed in a situation that the leading end of the sheet is positioned in a fixation nip, and also, the intermediate part of the sheet is positioned in the transfer nip of the transfer part), the average of the upper limit value and the lower limit value of the speed at the fixation printing is made equal to the average of the speed that obtains the shortest conveying distance of the transfer material until the trailing end of the sheet reaches the transfer nip and the speed that obtains the longest conveying distance, consequently, the image forming apparatus is set so that image failures may hardly occur. <P>COPYRIGHT: (C)2007,JPO&INPIT |
