Patent ID: 8113514

Claim:
A sheet decurling device that decurls a recording sheet, comprising: a moving unit including a first transportation path and a second transportation path that can selectively link to a main transportation path of the recording sheet, a first roller arranged between the first transportation path and the second transportation path, a second roller capable of making contact with the first roller across the first transportation path, a third roller capable of making contact with the first roller across the second transportation path, and a driving source that drives the first roller, and that moves its position such that the first transportation path and the second transportation path are selectively linked to the main transportation path; a moving position detecting unit that detects a position of the moving unit; and a mechanism that varies, upon the moving unit moving to a position at which either one of the first transportation path and the second transportation path is linked to the main transportation path, a pressing force of the second roller or the third roller with respect to the first roller, wherein the mechanism includes an elongated hole formed along a longitudinal direction on a side plate that is arranged separately from the moving unit in a moving direction of the moving unit, into which a rotating shaft of the first roller is inserted, a freely-moving supporting unit that is arranged on a moving unit side, into which the rotating shaft of the first roller is inserted along the longitudinal direction in the moving direction of the moving unit, and supporting units in which rotating shafts of the second roller and the third roller are inserted, respectively, and the freely-moving supporting unit moves without interfering with the first roller, upon a movement of the moving unit continuing when the rotating shaft of the first roller is pressed, according to a moving direction of the moving unit, against one end of the elongated hole, and causes the second roller and the third roller to move independently from the first roller, thus increasing the pressing force of the second roller or the third roller with respect to the first roller.