SHEET STACKING APPARATUS AND IMAGE FORMING APPARATUS

摘要

A sheet stacking apparatus includes an endless belt member onto which sheets are stacked and which moves rotationally to convey the sheets; a plurality of holding members that is provided on the belt member and that holds the sheets down to a sheet stacking surface of the belt member to nip the sheets; and sheet detecting portions which detect presence or absence of sheets between the holding members and the sheet stacking surface of the belt member, the sheet detecting portions each include a light emitting portion that emits light and a light receiving portion that receives the light, and the light emitting portions and the light receiving portions are fixedly provided below the sheet stacking surface of the belt member so that the light emitting portions and the light receiving portions detect presence or absence of a sheet at times when facing the holding members.