Patent ID: 7850162

Claim:
A sheet feeding device comprising: a tray configured to support sheets, the tray being movable upward and downward; a driving portion configured to move the tray upwardly and downwardly; an air blowing portion configured to blow air so as to raise the sheets supported on the tray; an uppermost-sheet detection mechanism configured to detect a height of the uppermost sheet of the sheets raised by the air blown from the air blowing portion; a control portion configured to control upward and downward movements of the tray in accordance with detection by the uppermost-sheet detection mechanism such that the uppermost sheet is positioned in a predetermined range; an attraction conveying portion having an attracting portion and a conveying portion and is configured to attract an uppermost sheet of the sheets raised by the air blowing portion by the attracting portion and to convey the attracted sheet by the conveying portion; and a next-sheet detection mechanism configured to detect a height of a next sheet subsequent to the uppermost sheet after an attraction operation of the uppermost sheet is started by the attraction portion and before the uppermost sheet is conveyed by the attraction conveying portion.