Patent ID: 7984908

Claim:
A document feeding device for handling and reverting double-sided document sheets to an original sequence, comprising: a housing unit comprising a delivery passage, a flipping passage connected to the delivery passage, a bypass area on a side of the delivery passage and the flipping passage, a return passage on a side of the bypass area, an upper turning passage, and a lower turning passage, wherein the delivery passage has a feeding end, an exhausting end below the feeding end, and a scanning section between the feeding end and the exhausting end, the flipping passage has a guiding inlet corresponding to the exhausting end and a guiding outlet connected to the delivery passage, the return passage has an inner end corresponding to the guiding inlet, and an outer end opposite to the inner end, the upper turning passage, adjacent to a side of the bypass area, has a first internal end corresponding to the exhausting end and a first external end opposite to the first internal end, and the lower turning passage has a second external end corresponding to the first external end and a second internal end opposite to the second external end; and a switching unit, pivotally disposed in the bypass area, comprising a first switching member, a second switching member connecting to a side of the first switching member, and a guiding passage between the first switching member and the second switching member, wherein the second switching member has a curved guiding surface opposite to the guiding passage, and when the switching unit is in a first position, the first switching member is mounted to allow communication between the exhausting end and the return passage, the second switching member moves close to the upper and lower turning passages, and the curved guiding surface is located between the first and second internal ends to form a curving path communicating the upper turning passage with the lower turning passage, and when the switching unit is in a second position, the first switching member is mounted to allow communication between the guiding inlet and the return passage, and the second switching is mounted to allow communication between the exhausting end and the upper turning passage.