The scanning mirror is doing two things. It's moving the beam and it's reflecting the light pulses from the barcode back to the detector. I suspect those two smaller mirrors near the detector are concave and act like lenses to focus more of the reflected light onto the detector for better S/N ratio. It looks to me like the two vertically stacked beams are offset slightly in the horizontal plane (as it sits on the bench.) I think one beam aligns with one large/small mirror pair to focus back to the detector and the other beam aligns with the other pair. As for why blocking one beam disables the other… Gonna need more coffee for that mystery.

Going to guess each laser has a polarising filter in front of it, so that the scanner can switch between different polarisation beams on the fly. Helps to get good reads with very reflective media, and also helps with detecting the difference between reflected and absorbed light in the barcode itself. Normally this should rad the massive barcode on the side of packages, the 2 crossed beams mean it can read any barcode on the visible side.

Probably the kind of scanner you find in a shipping facility where packages pass on a conveyor belt. The industrial scanners usually need a GPIO-pin (scan enable) pulled before it will scan and interpret anything. The Encoder input is for a shaft encoder on the conveyor belt to help the scanner figure out how fast the barcodes are passing.

If you can't do anything with it you can still use it as a dace floor laser effect :D. The industrial barcode scanners that exists today are so small and only get power, Ethernet and switching signals over M12 plugs :) all standard.

Fascinating scanner. Probebly used in a massive warehouse, I bet you need to plug it ito something before it will work. I love the spinny mirror. :)

,Not that looking online a Datalogic barcode scanner was used for the first ever purchase in a supermarket using barcodes, so they seem to be quite experienced in making barcode scanners!, and yes they are Italian, something I didn't expect reallly.

Hi from Italy too!

Initially I thought the stacked lasers would be because of the two axis, but perhaps they are also different polarisation? Maybe a differential pair for more accuracy or to deal with plastic wrap over barcodes?

Giant barcode scanner reminded me of kzfaq.info/get/bejne/idGcapSm19evpWQ.html