Lines in the file when I scan with the ADF in the Image Class MF4770

[Harrinson]

Hi.

I am the owner of a Mulifunction Printer Canon MF4770 Image class.

When I scan a document using the ADF, I get two lines along all the page digitalized.

Is there any way to clean the ADF scaner?

why do i get this line in the file ?

I attached an example in order to you can see what I'm  trying to explain.

Regards