Patent ID: 6975435

Claim:
An image reader having a document moving mode in which an original document carried through a document passing area on an original table is read by a readout section, characterized in that: the readout section comprises a light source for irradiating light to the document; a first standard white board being longer than the length of said document passing area with respect to the main scanning direction is provided outside the document passing area; a second standard white board is provided in an external region of an end portion of the document passing area with respect to the main scanning direction; a control section controls the readout section in such a way that, in the document moving mode, the readout section reads the first standard white board prior to the initiation of the document read to thereby perform the shading correction, and after the document read has been initiated, said readout section reads the moving document as well as the reflected light of the second standard white board, so as to correct the quantity of irradiation light of the light source, based on a difference between a first data of quantity of light of the first standard white board and a second data of quantity of light of the second standard white board, and reads subsequent moving documents as well as the reflected light of the second white board without rereading the first standard white board so as to continue to correct the quantity of irradiation light with respect to the subsequent moving documents.