Patent ID: 8041284

Claim:
An automatic document feeder device having a device body disposed on a platen of a document reading device, the device body being pivotably openable relative to the document reading device by being hingedly connected thereto, the automatic document feeder device comprising: a detector operable to detect a document-stack state of a document on at least one of a feeder tray and an output tray provided on the device body, the document-stack state indicates (a) presence or absence, (b) an amount or (c) a size of documents stacked on the feeder tray or the output tray; a driver operable to drive the device body to be pivotably opened in an upward direction from the platen; an instructor operable to give an instruction such that the driver drives the device body; and a controller operable to (i) suppress the driving of the device body or (ii) control an amount of the driving based on a detection result of the detector in priority to the instruction, the controller controls the driving amount by adjusting at least one of an opening angle and an opening speed of the device body, according to the document-stack state.