How do I get my S1300 scanner to show up in Yosemite Preview File > "Import from scanner" option?
You can only scan into Preview and other applications which use Apple's standard scanning architecture (such as Image Capture) if the scanner is provided with an ICA scan driver. Fujitsu do not supply ICA drivers for the ScanSnap scanners (at least as far as I know) and therefore the ScanSnap scanners will not work with preview or Image Capture etc. Fujitsu supply their own scanning drivers which other applications have to support directly, and some do (such as Mariner Software's Paperless).