Sheet Feeding Device and Image Forming Device

A sheet feeding device, comprising:

• a sheet stacking unit that is enabled to be lifted and lowered while a bundle of sheets is stacked;
• a pick-up roller that is in contact with a top surface of the bundle of sheets and is enabled to move up and down in accordance with the lifting and lowering movement of the sheet stacking unit, and that sends a sheet of the bundle of sheets toward downstream side in a carrying direction;
• a pair of rollers that is arranged at downstream side in the carrying direction of the pick-up roller, and when multiple sheets are sent out by the pick-up roller, that separates the first sheet from the second sheet or later and feeds the first sheet toward downstream side in the carrying direction, and restricts a movement of the second sheet or later;
• a separation member that is arranged between the pick-up roller and the pair of rollers and that is in contact with a leading end of the sheet that is sent out by the pick-up roller and limits the number of the sheet carried to the pair of rollers;
• and
• a hardware processor that determines a height position of the pick-up roller corresponding to a type of the sheet stacked on the sheet stacking unit and lifts and drives the sheet stacking unit to set the pick-up roller to be at the determined height position.