| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus which shortens first print time, and realizes cost reduction by reducing a drive source. <P>SOLUTION: A rotation shaft 51c of a pair of discharge rollers 51 is provided with a gear 139 to which a driving force is transmitted from a drive motor 61 which rotates a fixation roller at a system speed V1, and a pulley 140 to which a rotation driving force is transmitted from a reverse motor 62 for a switchback. The gear 139 and the pulley 140 have one way clutches 201 and 211 therein for transmitting to the rotation shaft 51c only a rotation driving force in the same direction as the rotation direction of the pair of discharge rollers 51 when the pair of discharge rollers 51 discharge a sheet. While the sheet to be discharged is conveyed through a fixation nip, the reverse motor 61 is rotated at a speed corresponding to the V1, and after the rear end of the sheet has passed the fixation nip, the reverse motor 62 is switched to rotate at high speed. Thereby the pair of discharge rollers 51 rotate at high speed, and time required for discharging the sheet is shortened after the switch. <P>COPYRIGHT: (C)2013,JPO&INPIT |
