Pro C5100s Lines when adf scanning

[nick40]

I get colored lines only when I am scanning thru the adf but only on the first side. (It is a single pass adf)
Scanning on the glass works fine. Prints are fine.
Lines are intermittent and can be all the way across or as small as an inch and can be solid or dashed.
I replaced the SIO, IPU, sub IPU slit glass LED lamp and Lens block assembly. I cleared the scanner memory and updated all firmware to the latest versions.
Any other ideas?

[slimslob]

Re: Pro C5100s Lines when adf scanning

Try cleaning the slit glass and scanner mirrors. Projection path through the mirrors is not the same on the platen as through the slit glass. As the scanner moves from home position, the projection point on each mirror moves slightly. That is why the mirrors are as large top to bottom as they are. Because of this, small dust particles can cause line on one and not the other. I have also seen lines that are only seen on part of the copy when on the platen glass.

[nick40]

Re: Pro C5100s Lines when adf scanning

Thanks for the tip. I replaced the slit glass and I've cleaned the mirrors several times already.

Any other thoughts?

[qbert69]

Re: Pro C5100s Lines when adf scanning

Try cleaning the slit glass and scanner mirrors. Projection path through the mirrors is not the same on the platen as through the slit glass. As the scanner moves from home position, the projection point on each mirror moves slightly. That is why the mirrors are as large top to bottom as they are. Because of this, small dust particles can cause line on one and not the other. I have also seen lines that are only seen on part of the copy when on the platen glass.

All above good points!....but also the fact that color scanning has a wider color frequency sensitivity...Red=Long color wavelength, blue=shorter color wavelength!...based on this, blue has a finer/higher resolving power (just like blu-ray dvd laser) and because of this, the blue CCD portion will pick up dust that is MUCH finer than the red portion of the CCD!

Case in point, Nikon uses an infra-red channel in their film scanning in relation to the RGB channels to detect and remove dust with a computer algorithm!

https://en.wikipedia.org/wiki/Infrared_cleaning