Patent ID: 8553295

Claim:
An image reading apparatus comprising: a conveyance member configured to convey a sheet; a reading unit configured to read an image on the sheet conveyed by the conveyance member; a calibration member including a white reference region for calibrating reading with the reading unit; and a driving unit configured to move the calibration member to switch between a first state and a second state, wherein in the first state, the white reference region locates at a reading position of the reading unit when the reading unit reads the white reference region while the sheet does not exist at the reading position, and in the second state, the white reference member does not locate at the reading position and does not contact with the sheet when the sheet is conveyed for reading of the image by the reading unit, wherein the calibration member is rotatably supported and does not have a function to convey the sheet, and the driving unit rotates the calibration member to switch between the first state and a second state.