Albert,
Look up the model you are thinking of getting and click on the "Specifications" tab.
Look at Photoelectric Device or Optical Resolution.
If it says EPSON MatrixCCD® that's the one you want. If it says Color CIS line sensor that's the one you DON'T WANT.

The models with PHOTO in the name has equipment to help with scanning negatives, slides, etc. I use my V33 to scan collectibles and not negatives/slides so it's good enough for me.

Here's a link for Epson scanners:
http://www.epson.com/cgi-bin/Store/jsp/ProductCategory.do?BV_UseBVCookie=yes&oid=-8172