Image reading apparatus and image forming apparatus

An image reading apparatus comprising:

• a stacking portion on which a sheet is to be stacked;
• a feeding unit configured to feed the stacked sheet in a feeding direction;
• and
• a reading unit configured to read an image on the sheet fed by the feeding unit,
• wherein the stacking portion includes:
• a first support surface configured to support the sheet,
• a second support surface configured to move, in a widthwise direction perpendicular to the feeding direction, between a first position where the second support surface supports the sheet together with the first support surface and a second position where the second support surface retracts from the first position,
• a first regulating unit provided on the first support surface to be movable in the widthwise direction, having a first rack portion in which a plurality of first teeth is linearly provided, and configured to regulate a position of the sheet stacked on the stacking portion in the widthwise direction,
• a second regulating unit provided on the second support surface to be movable in the widthwise direction together with the second support surface, having a second rack portion in which a plurality of second teeth is linearly provided, and configured to regulate a position of the sheet in the widthwise direction, and
• a gear unit arranged so as to mesh with both the first rack portion and the second rack portion and configured to interlock the first regulating unit and the second regulating unit,
• wherein the first support surface includes a downstream support portion configured to support the sheet on a downstream of the second support surface with respect to the feeding direction and configured to cover both the entire first rack portion and the entire second rack portion as viewed from above regardless of positions of the first regulating unit and the second regulating unit.