Image forming apparatus and image forming method each of which allows movement range of component to be switched that is used to adjust position of sheet in width direction depending on conveyance interval between sheets

An image forming method that is executed by an image forming apparatus including an image forming portion, a conveying portion, a supply portion, and a sensing portion, the image forming portion being configured to form an image on a sheet, the conveying portion being provided so as to be movable along a width direction on an upstream side of an image forming position by the image forming portion in a conveyance path of the sheet in a conveyance direction of the sheet, the conveyance path extending through the image forming position, the width direction being orthogonal to the conveyance direction, the conveying portion being configured to nip and convey the sheet, the supply portion being configured to periodically supply the sheet to the conveyance path, the sensing portion being configured to sense a position of the sheet in the width direction before a back end of the sheet supplied by the supply portion passes through the conveying portion, the image forming method comprising:

• a first movement step of moving the conveying portion that is nipping the sheet from a reference position defined in advance within a movement range along the width direction around the reference position on a basis of a result of sensing by the sensing portion;
• and
• a second movement step of moving the conveying portion to the reference position in a non-nipping period from time when the conveying portion finishes nipping the sheet to time when the conveying portion starts to nip the next sheet, wherein
• the supply portion periodically supplies the sheet in a designation supply mode designated in advance among a plurality of supply modes having the non-nipping periods different from each other, and
• the conveying portion that is nipping the sheet is moved in the first movement step from the reference position within the movement range corresponding to the designation supply mode among a plurality of the movement ranges corresponding to a plurality of the supply modes.