Patent ID: 8746697

Claim:
A sheet transport mechanism comprising: a pair of transport rollers including a first roller which is rotated by a driving force from a drive source, and a second roller which is pressed against the first roller and driven to be rotated, the pair of transport rollers being configured to nip and transport a recording medium in a nip portion between the first roller and the second roller; a pair of first levers provided at both ends of a rotary shaft of the second roller, each of the pair of first levers having a bearing aperture which rotatably supports the rotary shaft, each of the pair of first levers being configured to swing in directions of contact with and separation from the first roller with a first swing shaft extending in a direction parallel to rotary shafts of the first and second rollers as a rotation center; a pair of second levers arranged to swing in the directions of contact with and separation from the first roller around second swing shafts each provided orthogonal to the associated first swing shaft and a pressing direction of the second roller and lateral to an associated one of the pair of first levers, the pair of second levers being configured to cause the first levers to move in the directions of contact with and separation from the first roller when one ends of the pair of second levers abut the first levers; and an elastic member connected to the other ends of the pair of second levers and configured to pull the pair of second levers toward a center of the rotary shaft of the second roller in a direction parallel to the rotary shaft of the second roller, the elastic member being disposed at a position between the rotary shaft of the first roller and the rotary shaft of the second roller in the directions of contact and separation of the second roller with and from the first roller, and wherein when the elastic member pulls the other ends of the pair of second levers, the one ends of the pair of second levers swing in a direction toward the pair of first levers being pressed, so that the pair of second rollers are pressed against the pair of first rollers.