The following causes can be considered.
Solutions
Load and eject paper without printing to clean the paper path.
Cleaning the Paper Path for Ink Smears
Remove any dust or dirt that adheres to the originals, and clean the scanner glass.
Cleaning the Scanner Glass
If you press with too much force, blurring, smudges, and spots may occur.
Do not press with too much force on the original or the document cover.
Placing Originals on the Scanner Glass