The page unsupported/canon-4400.html says the scanner uses chip=GL841, but more recent software reports it as GL843:
found USB scanner (vendor=0x04a9 [Canon], product=0x2228 [CanoScan], chip=GL843) at libusb:001:002 The bug reporting system gave some problem with security certificates that I didn't want to worry about, so I'm sending it this way.
