Patent ID: 8279497
Filing Date: 2012-10-02
Classification: H04N

Abstract:
1. An image-reading device comprising: a document-supporting base having a transparent member on which a document is placed; a document-pressing member disposed on the document-supporting base so as to cover the transparent member, the document-pressing member being capable of opening and closing on the document-supporting base; a reading unit having a light source and capable of reading an image from the document placed on the transparent member while the light source irradiates light on the document; a controlling unit configured to control the reading unit to execute a first scanning operation to output image signals for the image on the document while the light source is lit, and a second scanning operation to output image signals for the image on the document while the light source is not lit; a determining unit configured to determine whether outside light has penetrated the document-supporting base based on the image signals for the second scanning operation outputted from the reading unit; a correction processing unit configured to perform a correction process to remove effects of outside light on image signals outputted from the reading unit in the first scanning operation after the determining unit determines that outside light has penetrated the document-supporting base; and a shading correction unit configured to perform, based on white reference data, a shading correction on image signals outputted from the reading unit in the first scanning operation, wherein, when the determining unit determined that the outside light has penetrated the document-supporting base, the correction process modifies the white reference data from original white reference data to modified white reference data based on the image signals that have been outputted from the reading unit in the second scanning operation when the light source is not lit, such that some values of the modified white reference data are greater than corresponding values of the original white reference data, and wherein the modified white reference data is used for the shading correction performed on image signals that are output from the reading unit in the first scanning operation after the determination unit determined that the outside light had penetrated the document-supporting base.