Patent ID: 8210515

Claim:
A document transport apparatus for transporting a document sheet to a predetermined position to read the document sheet, comprising: a paper feed tray to mount document sheets; a document reading portion for reading both sides of each of the document sheets; transport means for transporting the document sheets on the paper feed tray to the document reading portion; a sheet discharge tray to store the document sheets of which both sides are read; a first switchback portion for switching back each of the document sheets of which the front side is read in the document reading portion to transport again to the document reading portion; a second switchback portion for switching back each of the document sheets of which both sides are read in the document reading portion to discharge to the sheet discharge tray; first switchback means provided in the first switchback portion to transport two document sheets in mutually different directions, the first switchback means having a first switchback path and a first switchback roller pair each for guiding overlapping two document sheets in the mutually different directions or the same direction; nip force switching means for switching a nip force to nip a document sheet of the first switchback roller pair; and second switchback means provided in the second switchback portion to transport two document sheets in mutually different directions.