make the scanner scan the entire paper pages, not skip anything near the borders?

I am scanning some paper pages using the document feeder of Xerox WorkCentre 7830.

The scanner didn't scan the entire paper pages, and skip some part near the borders of the paper pages.

For example, here is a page from my scanned pdf file. the handwrittend  "Regular surface" on the right is cut off by the scanner to be *Regular su".

However in the scanner control panel, I have specified the custom scan area to be slighly larger than the paper page size.This is also indicated by the white margins in the pdf page.

I have also choose 0.0 for Edge Erase option.

So how can I make the scanner scan the entire paper pages, and do not skip anything near the borders of the paper pages?

Thanks.