An automatic document conveying device for an image processing machine in which a transparent plate, on which to place a document to be processed, is disposed on the upper surface of the housing. The automatic document conveying device includes a document table for holding documents to be processed, a document receiving tray for receiving documents after they have been processed, and means for feeding documents from the document table through the processing to the document receiving tray. A document delivery roller moves the document from the transparent plate, following processing of the document, along a document delivery passage. Document discharge rollers located at the downstream end of the document delivery passage move the document from that point to the document receiving tray. The document delivery rollers are driven at a higher speed than are the document discharge rollers. A one-way clutch permits the document discharge rollers to be rotated at a higher peripheral speed than the peripheral speed at which the document discharge rollers are driven. Consequently, a document being delivered by the document delivery rollers to the document discharge rollers causes the document discharge rollers to rotate at the higher speed of the document delivery rollers. This prevents the document from bending and being damaged. Once the trailing end of the document has cleared the document delivery rollers, the document discharge rollers are driven at their lower speed, and so the document speed is reduced and the document delivered onto the document receiving tray at this lower speed, permitting the forming of a stack of delivered documents.