Sheet feeding apparatus and printing apparatus

A sheet feeding apparatus comprising:

• a stacking unit capable of stacking sheets;
• a feed unit configured to feed an uppermost sheet of the sheets stacked on the stacking unit by a feeding roller;
• a separation unit configured to separate the uppermost sheet of the sheets, wherein the separation unit includes a first separation portion and a second separation portion, which is provided upstream of the first separation portion with respect to a conveying direction of the sheet by the feed unit, and which has a greater separation action on the sheet than that of the first separation portion;
• a thickness obtaining unit for obtaining information on the thickness of the sheet;
• and
• a change unit for changing the position of the stacking unit, wherein the position of the stacking unit for bringing the sheet fed by the feed unit into contact with the first separation portion without bringing the sheet into contact with the second separation portion is defined as a first position, the position of the stacking unit for bringing the sheet fed by the feed unit into contact with the second separation portion is defined as a second position, and the change unit selects the position of the stacking unit from a plurality of positions including the first position and the second position based on the information on the thickness obtained by the thickness obtaining unit;
• a detection lever which contacts the uppermost sheet and moves according to the position of the uppermost sheet, wherein in a case where the stacking unit is in either one of the first position or the second position, a position at which the uppermost sheet and the detection lever abut each other is downstream, with respect to a conveying direction, of a position where the uppermost sheet and the feeding roller abut each other;
• a position detection unit configured to detect the position of the detection lever;
• and
• a control unit configured to change the position of the stacking unit by the change unit based on a detection result of the position detection unit.