Patent ID: 7522871

Claim:
An auto document feeder adapted to be disposed on an image forming apparatus, the image forming apparatus including a scanning unit, said auto document feeder comprising: a housing unit having a first end portion, a second end portion opposite to said first end portion, and a feeding tray disposed on said first end portion; a first path disposed in said housing unit and having an upstream end and a downstream end extending toward said first end portion of said housing unit; a second path having an upstream end in spatial communication with said downstream end of said first path such that the scanning unit is disposed between said downstream end of said first path and said upstream end of said second path, and a downstream end; an inverting path extending from said first end portion to said second end portion and disposed above said second path, said inverting path having an upstream end and a downstream end and in spatial communication with said first path; a bypass path disposed in said first end portion of said housing unit and having an upstream end in spatial communication with said second path, and a downstream end in spatial communication with said inverting path; a feeding roller unit disposed between said feeding tray and said upstream end of said first path; a first transfer roller unit disposed on said first path; a second transfer roller unit disposed on said second path and upstream of said upstream end of said bypass path; an ejecting roller unit disposed in proximity to said downstream ends of said second path and said bypass path and external to said bypass path; and a switching gate internal to said ejecting roller unit and disposed pivotally on said housing unit, said switching gate having a free end pivotable among a first position whereat said free end extends onto a portion of said second path immediately downstream of said upstream end of said bypass path, a second position whereat said downstream end of said bypass path is closed by said free end of said switching gate, and a third position whereat said upstream end of said bypass path is closed by said free end of said switching gate.