AUTOMATIC DOCUMENT FEEDER AND IMAGE FORMING DEVICE

PROBLEM TO BE SOLVED: To provide an automatic document feeder (ADF) and an image forming device obtaining conveying roller driving strong in load variation by impact to a conveying roller drive system at driving of a separating means by adjusting strength of a conveying roller nipping pressure according to thickness of document paper to be passed. SOLUTION: The automatic document feeder has a switch-back route 42 for separating a piled up bundle of documents by every one sheet, feeding it to an image reading position and reversing front and back of the document by switch-back conveying after the document is passed through a reading position; and a roller separating means 44 capable of releasing a nipping pressure of a pair of conveying rollers 37, 38 provided on the switch-back route 42. A fed current to a conveying roller drive source 51 is varied at driving of the roller separating means. COPYRIGHT: (C)2007,JPO&INPIT