Image forming apparatus

An image reading apparatus includes a sheet feeding unit configured to sequentially feed documents loaded on a document positioning plate, a reading sensor configured to read a document of the plurality of documents fed by the sheet feeding unit, an acquisition unit to acquire an interval of the document between a trailing edge of a preceding document and a leading edge of a next document conveyed through the conveyance path, and a reading unit to execute a first reading mode using the reading sensor to read the document conveyed at a first conveyance speed, and a second reading mode using the reading sensor to read the document conveyed at a second conveyance speed that is lower than the first conveyance speed, wherein the reading unit executes the second reading mode after the first reading mode when the interval of the document is less than a predetermined interval.