SCANNING APPARATUS HAVING FUNCTION TO CORRECT SHADING DATA

摘要

A scanning device having a shading data correction function is provided to correct image data according to illumination change and time when a plurality of documents are scanned through an ADF(Automatic Document Feeder). A sub white sheet(137) is installed to both ends of an ADF glass(135). A scanning head(140) obtains reference shading data by scanning a reference white sheet(133), and obtains image data and sub shading data by scanning the sub white sheet when a document fed to the ADF glass is scanned. A controller corrects the shading data of the image data by comparing the reference shading data and the sub shading data. The controller corrects the shading data of the image data as much as a difference between the reference shading data and the sub shading data when the reference shading data is different from the sub shading data. A white reference sheet(131) is prepared at a margin(X) of a stage glass or at a cover which covers a plat bed.