Well the scanning quality depends on the printer model and also certain printers I believe. It basically depends on how many DPI your scanner can scan at, and Lexmarks I believe have a moderately good dpi, so it might be that. I've dealt with lexmarks on a couple of occasions (the small-business type models') and their quality isn't that good, and I've seen better ones that lexmark.

But it might also be that your scanning surface (if it's a flat bed scanner of course) isn't that clear? That's why the quality gets kind of distorted.

Another thing you can do is change the DPI of your scanner, most Lexmarks I've dealt with scan at a default 150 DPI which can be increased to about 600 DPI (usually through the printer settings, which depend on your printer model...) and you will notice a big difference... You can also change your copy quality to best, so the it prints at a slower speed, however the copy might turn out better

Hope this helps, if not I don't think there isn't much you can do about it.