Slow Scanning Speed
To view the image on a monitor, set the output resolution to around 150 dpi. To
print, set it to around 300 dpi.
Set Fading Correction, Grain Correction, etc. to None.
Refer to "Image Settings" for your model from Home of the Online Manual for details.
In IJ Scan Utility, deselect the Correct slanted text document / Detect the
orientation of text document and rotate image checkbox and scan again.
Settings (Document Scan) Dialog Box
Settings (Custom Scan) Dialog Box