Sheet feeding apparatus and image forming apparatus

摘要

A sheet feeding apparatus includes a containing unit, a lifting and lowering unit, a loosening unit, a feed unit, a sheet-surface detection unit, an aligning member, a trailing-edge detection unit, a double-feed detection unit, and a control unit. Sheets, of a sheet bundle contained in the containing unit and lifted and lowered, are loosened by blowing air into the sheet bundle and fed. An end face of the contained sheet bundle is aligned on a trailing-edge side. The trailing-edge detection unit moves with the aligning member and detects a sheet surface of a top of the sheet bundle on the trailing-edge side. Where double feed from the containing unit is detected, a detection operation detects, in consideration of a trailing-edge detection unit result, whether the aligning member is located at a position at which the end face of the sheet bundle on the trailing-edge side is aligned.

主权项

1. A sheet feeding apparatus comprising:
a containing unit that contains a sheet bundle formed of a plurality of sheets; a lifting and lowering unit that lifts and lowers the sheet bundle contained in the containing unit; a loosening unit that loosens the plurality of sheets of the sheet bundle contained in the containing unit by blowing air into the sheet bundle; a feed unit that feeds sheets loosened by the loosening unit; a sheet-surface detection unit that detects a sheet surface of a top of the sheet bundle contained in the containing unit; an aligning member that is movable to align an end face of the sheet bundle contained in the containing unit on a trailing-edge side in a direction of feeding performed by the feed unit; a trailing-edge detection unit that moves together with the aligning member and that detects a sheet surface of the top of the sheet bundle on the trailing-edge side; a double-feed detection unit that detects occurrence of double feed in which two or more sheets are fed in an overlapping manner by the feed unit; and a control unit that performs control in which, in a case where the double-feed detection unit does not detect double feed from the containing unit, a detection operation is not executed on the containing unit, and in which, in a case where the double-feed detection unit detects double feed from the containing unit, the detection operation is executed on the containing unit such that, as part of performing the detection operation, the detection operation detects whether the aligning member is located at a position at which the end face of the sheet bundle on the trailing-edge side is aligned, wherein the detection operation is performed in consideration of a result of detection performed by the trailing-edge detection unit when the sheet bundle lifted by the lifting and lowering unit reaches a position at which the sheet surface is detected by the sheet-surface detection unit.