Sheet feeding device, image forming apparatus, and image forming system

A sheet feeding device includes: a sheet stacking member; an air blowing unit configured to blow air onto the sheet bundle placed on the sheet stacking member to suspend multiple sheets of the sheet bundle; a lifting/lowering unit configured to lift/lower the sheet stacking member; an optical reflection sensor configured to detect a suspended sheet suspended by the air blowing unit; and a control unit configured to control the lifting/lowering unit based on an output value of the optical reflection sensor. The optical reflection sensor is configured to be capable of detecting an area corresponding to multiple sheets in a sheet suspension zone extending between a non-suspended sheet bundle and a conveying member configured to convey an uppermost sheet of the multiple suspended sheets. The non-suspended sheet bundle is made up of sheets not suspended during a period when air is blown by the air blowing unit.