Canon BJC-3000 - Manual (Page 280)

280 Troubleshooting - Scanning result is unsatisfactory
Scanned image is of uneven quality
The scanned image is coarse and blurry.
Check Is the resolution setting high enough?
Resolution determines the precision of the scanned image.
The greater the number of dots used to draw an image, the greater the pre-
cision and the higher the quality of the scanned image. For a better quality
image, select a high number.
Please note that the scanning speed becomes slower and the file size of
the scanned image becomes larger when you use a higher resolution.