US Patent 7812975 Prescanning in image printing/reading apparatus

An image printing/reading apparatus in which a reference white board for prescanning can be prevented from being soiled with ink, and the influence of stray light from a paper discharge port can be reduced. A commonality of a print sheet path for conveyance of print sheet and a document path for conveyance of document is at least partially realized as a common path. A reading unit is provided with a reference white board for shading correction used upon execution of prescanning. Upon execution of document reading, the reading unit and the reference white board are moved to a document reading position. On the other hand, upon execution of prescanning, the reading unit and the reference white board are moved to a retreat position where the influence of ambient light is reduced. Further, upon printing, the reading unit and the reference white board are also moved to the retreat position for preventing the reference white board from being soiled with ink.