Patent ID: 8550459

Claim:
An image forming apparatus which includes a sheet feeding apparatus and an image forming portion which forms an image on a sheet fed from the sheet feeding apparatus, the image forming apparatus comprising: a sheet tray on which the sheet is stacked; a feeding member which feeds the sheet stacked on the sheet tray; an aligning member which aligns a width of the sheet stacked on the sheet tray, in a direction crossing a sheet feeding direction; a size detecting portion which detects the width of the sheet stacked on the sheet tray based on a detection of a position of the aligning member; an information inputting portion which receives an input of width size information of the sheet; a start button which indicates a start of a sheet feeding operation to feed the sheet stacked on the sheet tray by the feeding member; and a controlling portion which compares the width size information based on a detection of the size detecting portion and the width size information of the information inputting portion after the start button is pressed to indicate the start of the sheet feeding operation by the feeding member and before the feeding member starts feeding the sheet stacked on the tray, and the controlling portion does not start a sheet feeding operation of the feeding member when the pieces of width size information are different.