The scanner is rated for both 220 and 110V AC operation - the power lead isn't particularly relevant (other than getting a US plug spliced on to it).There should be an obvious slider switch near where this plugs in to switch between 110 and 220 - on later models it autosenses the input voltage.
http://www.readsoft.com/external/HTML_certlist/Datasheets/Panasonic/KV-S3085KV-S3105C.pdf