Scanning device is for digitalization of documents, such as construction drawings, being able to process both low contrast documents and those of high contrast

摘要

The scanning device is for digitalization of documents, such as construction drawings, being able to process both low contrast documents and those of high contrast. It has a through light source of which the light power can be adjusted at individual points or sectionally to the actual background level. Dark areas are strongly through-illuminated whilst light areas are virtually left with no illumination. In the left area, the document in accordance with the basic profile (10) is light and in the right area is dark. Peaks (11,12) extend out of the basic profile.