Original document supply device for image forming device, and image forming device equipped with the same

The ADF 11 is a device for feeding an original document toward an original document scanning position R, comprising an original document loading unit 31 , paper feeding roller 51 , pressure sensor 33 and lift plate drive unit 35 . The original document loading unit 31 comprises a lift plate 41 allowing an original document to be loaded and vertically movable in an original document loading direction. The paper feeding roller 51 is disposed above the lift plate 41 disposed at the lowermost position with an interval therebetween, and is capable of moving upwardly in coordination with a force received from below from the lift plate 41 . The pressure sensor 33 is capable of detecting upward pressure on the paper feeding roller 51 . The lift plate drive unit 35 causes the lift plate 41 to be lowered upon detection of upward pressure on the paper feeding roller 51.