Patent ID: 9077822
Filing Date: 2015-07-07
Classification: H04N

Abstract:
1. An image reading apparatus comprising: a conveyance unit configured to convey a sheet; a reading unit configured to read, in a reading position, the sheet being conveyed by the conveyance unit, based on a set reading mode, the reading mode including a first reading mode and a second reading mode different from the first reading mode; a foreign material detection unit configured to detect a position of a foreign material in the reading position, based on image data output from the reading unit while the sheet is not conveyed to the reading position; a moving unit configured to move the reading unit, to change the reading position; a number determination unit configured to determine a number of performing a detection process of causing the moving unit to change the reading position and of causing the foreign material detection unit to detect the position of the foreign material, before the reading unit starts reading the sheet, based on the set reading mode; a counting unit configured to count a number of times the foreign material detection unit has completed the detection process; and a position determination unit configured to determine the reading position for reading the sheet based on a foreign material detection result of the foreign material detection unit by causing the detection process to be performed less than or equal to the number determined by the number determination unit before the reading unit starts reading the sheet, wherein the number of performing the detection process based on the first reading mode is set to be different from the number of performing the detection process based on the second reading mode, wherein when a reading position candidate is found in which no foreign material image is detected by the foreign material detection unit, the position determination unit determines the reading position candidate as the reading position for reading the sheet, and terminates a position determination process, and wherein when the number counted by the counting unit reaches an upper limit number without finding a reading position candidate in which no foreign material image is detected, the position determination unit terminates the position determination process and determines, as the reading position for reading the sheet, a reading position candidate with fewest foreign material images from among a plurality of reading position candidates for which the foreign material detection unit has completed the detection process.