I'd like to use a CanoScan 8400F scanner with my laptop, which is running Xubuntu 18.04. I can detect the scanner with both `lsusb`, which returns

> 
> Bus 002 Device 006: ID 04a9:221e Canon, Inc. CanoScan 8400F
> 
> 
> 

and `sudo sane-find-scanner`, which returns

> 
> found USB scanner (vendor=0x04a9 [Canon], product=0x221e [CanoScan], chip=GL842) at libusb:002:006
> 
> 
> 

However, neither `scanimage` nor SimpleScan will detect the scanner. I note that running `sane-find-scanner` without permissions also does *not* detect the scanner. A visit to the [Sane supported devices page](http://www.sane-project.org/lists/sane-mfgs-cvs.html#Z-CANON) suggests that my scanner should be supported, though that's apparently as of Sane 1.0.31. I appear to be running Sane 1.0.27. I've run `sudo apt-get update` to no effect.

What am I missing? Is there any way to get this to work short of compiling the latest version of Sane myself? (Because I'm not going to do that. It's not worth the trouble.)

Thanks,

--John