Patent ID: 8755731

Claim:
An image scanning device including an automatic document feeder, comprising: a feeding path through which an original document is fed in one direction from a paper supply port to a paper discharge port; a plurality of feed roller sets arranged along the feeding path so as to be spaced apart from each other and arranged to nip the original document to feed the original document along the feeding path when one side of the original document is scanned and when both sides of the original document are scanned, all of the feed roller sets being involved in feeding the original document; a scanning unit arranged to scan one side of the original document or both sides of the original document on the feeding path; and a selecting unit arranged to select a path between a paper discharge path that discharges the original document when one side of the original document is scanned and a reverse path that reverses the original document when both sides of the original document are scanned; wherein the plurality of feed roller sets includes at least one triple roller; when both sides of the original document are scanned, the feeding path includes the reverse path; when one side of the original document is scanned, the reverse path is not included in the feeding path; when one side of the original document is scanned, the at least one triple roller that is arranged on the feeding path and located between the paper supply port and the scanning unit nips the original document only once; when one side of the original document is scanned and when both sides of the original document are scanned, each of the plurality of the feed roller sets nips the original document at least one time to feed the original document along the feeding path; each triple roller of the at least one triple roller includes a pair of driven rollers facing each other and a drive roller arranged between the pair of the driven rollers; the feeding path and the at least one triple roller are arranged such that when one side of the original document is scanned, the original document passes between either of the pair of the driven rollers and the drive roller, and when both sides of the original document are scanned, the original document passes between either of the pair of the driven rollers and the drive roller and passes between the other of the pair of the driven rollers and the drive roller; the at least one triple roller includes a first triple roller arranged on the feeding path upstream, with respect to a feeding direction of the original document, of a scanning position for the original document; skew correction of the original document is performed by the first triple roller; the at least one triple roller includes a second triple roller arranged on the feeding path at an area of the paper discharge port; and the at least one triple roller includes a third triple roller arranged on the feeding path between the scanning position for the original document and the selecting unit.