Automatic document feeder

An automatic document feeder for feeding a document onto a platen glass of an image forming apparatus and discharging the document therefrom, the automatic document feeder comprising:

• a first roller;
• a second roller which is in parallel to the first roller at a specified space;
• a conveyer belt for conveying a document, the conveyer belt being an endless belt laid between the first roller and the second roller;
• a main frame for holding the first roller;
• a sub frame for holding the second roller, the sub frame being pivoted on the main frame, the pivot being out of a line drawn between an axis of the first roller and an axis of the second roller;
• and
• a stopper for preventing the sub frame from pivoting toward the opposite side of the line drawn between the axis of the first roller and the axis of the second roller to the side of the pivot of the sub frame.

An automatic document feeder for feeding a document into a platen glass of an image forming apparatus and discharging the document therefrom, the automatic document feeder comprising:

• a main frame;
• a subframe rotatably provided on said main frame;
• a first roller provided on said main frame;
• a second roller provided on said subframe in parallel to the first roller;
• a conveyer belt laid between the first roller and the second roller;
• and
• a stopper which holds the subframe on the main frame at a predetermined relation in which the distance between the first roller and the second roller becomes a predetermined distance.