Sheet feeding device with two cams

A sheet supplying/feeding device includes a sheet placing plate that receives at least a tip of a sheet, a feeding unit that feeds the sheet while being in contact with the sheet placed on the sheet placing plate, and a driving unit that drives the feeding unit. Preferably, cam members are provided at both ends of a rotating shaft of the feeding unit, displacement changing members are swingably provided in engagement with the cam members, the sheet placing plate is shifted synchronously with the swing of the displacement changing members through first elastic members, and the sheet placed on the sheet placing plate and the feeding unit are contacted and separated by the synchronous movement of the sheet placing plate and the displacement changing members.