I had great difficulty finding workable driver for my Epson print/scan/copy/fax device, since Epson did not support Linux [Ubuntu]. It took a OS update before I could get the scanning to work properly. The key here is where did you get the driver for the scanner and how well can other packages use it? Yes, you do seem to have an issue that seems to associate the Epson scanner with the video device in the config files.
Here is a question and possible fix.
Unplug the video device and keep the scanner plugged in and on. rename the LO config folder and reopen LO to recreate it. See if the video device is still listed. If so, then there may be something "outside" of the LO "system" that maybe causing the issue. Is the Video device and the scanner both Epson tech? If so, then that might cause some confusion somewhere.
To be honest, I deal with Win7 and various Ubuntu types of Linux - i,e, Ubuntu 13.xx / 14.xx, and Linux Mint. So I do not know the internals of Slackware or any RPM based Linux.
As I stated, I had a lot of trouble with an Epson Artisan 810 Print/Scan/Copy/Fax device. I could not get even half of its options to work properly with Ubuntu based OSs.