COPYRIGHT © 2001 CANON INC. CANON CLC1000/1000S/3100 REV.2 MAY 2001 PRINTED IN JAPAN (IMPRIME AU JAPON) 3-533. OPERATION AND TIMINGl. Reproduction Ratio Processinga) Reproduction Ratio Processing1 Horizontal Reproduction Ratio (main scanning direction)When writing image data into memory or reading image data from memory, data units are skippedwhen writing (reduction) or are read a number of times when reading (enlargement).2 Vertical Reproduction Ratio (sub scanning direction)The scanner is moved at different speeds to change the width of the line, scanning each pixel on theoriginal.See Table 3-302 for how the ratios are varied.Table 3-302b) Enlargement Correction ProcessingThe image data is corrected so that the difference in density between pixels will not vary excessivelywhen producing enlarged copies.Figure 3-331 shows image data of an original, image data at time of enlargement, and image data afterenlargement correction.Figure 3-331Original(image data)(writing)Line memory(reading)CopyingReproductionratio in mainscanningdirectionReproductionratio in subscanningdirectionDirectAll data is written inmemory as it is and readas it is.ReductionTo reduce to 1/2, everyother data unit is written inmemory.The scanner is movedfaster to increase thewidth of the line scanningeach pixel on the original.EnlargementTo enlarge by 200%, alldata is written in memoryas it is but read twice.The scanner is moved ata lower speed todecrease the width ofscanning over each pixelon the original.WW2WWW2W1 pixela. Original1 pixelb. Enlargement at 300%1 pixelc. After correctionImage densityImage density Image density
