Patent ID: 7344133

Claim:
An image forming apparatus, comprising: an image forming device configured to form an image on a sheet; a sheet feeding device configured to convey the sheet to said image forming device, said sheet feeding device includes an axis, a driving gear configured to rotate said axis and support said axis at one side thereof, a gear engaged with said driving gear, a feed roller, and a reverse roller upwardly and elastically supported by said axis and configured to be pressed against said feed roller at a pressure applied between said feed roller and said reverse roller, said reverse roller is supported at a free end side of said axis and disposed via a torque limiter, so as to be rotated in a sheet feeding direction and a direction opposite the sheet feeding direction; and a pressing device configured to provide a change in the pressure while the sheet is conveyed between said feed roller and said separation member such that a plurality of sheets conveyed between said feed roller and said reverse roller are separated and individually conveyed to the image forming device, said pressing device is positioned at a side of the reverse roller, wherein said pressing device is provided on the axis of the reverse roller and includes a housing and a rotating element rotatably provided in the housing, the housing has a first magnet provided on an inner circumference of the housing, the rotating element has a second magnet provided on an outer circumference of the rotating element, and the first magnet faces the second magnet and includes convex and concave parts such that a magnetic force between the first magnet and the second magnet are altered when the reverse roller is rotated.