CHAPTER 3 IMAGE READING/PROCESSING SYSTEMCOPYRIGHT © 2002 CANON INC. 2000 CANON iR1600/iR2000/iR1610/iR2010 SERIES REV.0 MAR. 2002 3-134.6 ABC (auto background control)The ABC function is used when the original has a dark background, not reproducing thecolor of the background while correctly reproducing the text and images of the original.The machine’s ABC function is enabled when the density adjustment function is set to‘auto’ in copier mode; if selected, the ABC circuit is used for the work.The digital image signals which are the result of A/D conversion are subjected to varia-tion of dynamic range to suit the level of the background color of the original so that themachine will recognize the background to be “white.”F03-406-01As shown, range A of a white background original is decreased like range B of a col-ored background original to remove the color from its background.Original surfaceA BOriginal withwhite backgroundOriginal withcolored backgroundBackgroundBackgroundBackgroundBackgroundFFh (white)00 h (black)FFh (white)00 h (black)Output levelA: dynamic range of a white background original.B: dynamic range of a colored background original.
