Automatic document feeder

An automatic document feeder, comprising:

• a main body, defining a passage for transporting a document;
• a feeding roller unit, including a feeding driving roller and a feeding idle roller coupling with the feeding driving roller, the feeding driving roller and the feeding idle roller disposed at opposite sides of the passage;
• a drawing-out roller unit, including a drawing-out driving roller and a drawing-out idle roller coupling with the drawing-out driving roller, the drawing-out driving roller and the drawing-out idle roller disposed at opposite sides of the passage, the drawing-out driving roller and the feeding driving roller being at the same side of the passage;
• and
• a belt set only to tightly surround the feeding roller unit and the drawing-out roller unit and contact with the feeding idle roller and the drawing-out idle roller for being driven to rotate and further drive the feeding idle roller and the drawing-out idle roller by means of a friction therebetween and then contacting and conveying the document into and out of the automatic document feeder by the cooperation of the feeding idle roller and the drawing-out idle roller.

An automatic document feeder, comprising:

• a main body, having a pedestal and a cover coupling with the pedestal, a document-guiding element mounted between the pedestal and the cover, a passage formed between the document-guiding element and the pedestal and cover, which includes an entering passage, an operating passage and an exiting passage;
• a feeding roller unit, including a feeding driving roller disposed at the document-guiding element and near to the entering passage, and a feeding idle roller coupling with the feeding driving roller disposed at a side of the entering passage opposite to the feeding driving roller;
• a drawing-out roller unit, including a drawing-out driving roller disposed at the document-guiding element and near to the exiting passage, and a drawing-out idle roller coupling with the drawing-out driving roller disposed at a side of the exiting passage opposite to the drawing-out driving roller, the drawing-out driving roller and the feeding driving roller being at the same side of the passage;
• and
• a belt set only to tightly surround the feeding roller unit and the drawing-out roller unit and contact with the feeding idle roller and the drawing-out idle roller for being driven to rotate and further drive the feeding idle roller and the drawing-out idle roller by means of a friction therebetween and then contacting and conveying a document into and out of the automatic document feeder by the cooperation of the feeding idle roller and the drawing-out idle roller.