Automatic document feeder

In <a href="/facts/Multifunction_printer/L4bh6dHB">multifunction or all-in-one printers</a>, <a href="/facts/Fax_machine/EBvf1cHA">fax machines</a>, <a href="/facts/Photocopier/aF7URdyU">photocopiers</a> and <a href="/facts/Image_scanner/7DEJFTwx">scanners</a>, an automatic document feeder or ADF is a feature which takes several pages and feeds the paper one page at a time into a scanner or copier, allowing the user to <a href="/facts/Image_scanning/7DEJFTwx">scan</a>, and thereby <a href="/facts/Photocopying/aF7URdyU">copy</a>, <a href="/facts/Printing/ta4QpeDE">print</a>, or <a href="/facts/Fax/EBvf1cHA">fax</a>, multiple-page documents without having to manually replace each page.
Most copiers allow scanning on the flatbed or platen (the "glass") or through a document feeder. The vast majority of fax machines have an ADF, allowing the unattended sending of multi-page faxes. ADF is so ubiquitous in fax machines that some fax machine owners use the machine as a scanner, faxing multi-page documents to themselves. Document feeders are described by speed, in pages per minute or ppm, and capacity, usually in a range from 10 sheets to 200.
There are two kinds of document feeders capable of two-sided (duplex) scanning: a reversing automatic document feeder or RADF scans one side of a page, then flips it and scans the other side. A duplexing automatic document feeder or DADF scans both sides in one pass. The advantage of the DADF is faster speed for two-sided originals. RADFs and DADFs are rated in images per minute (IPM), the number of sides they can scan each minute; this may depend upon the resolution being used (rather than the maximum resolution supported).

Automatic document feeder open-in-new

Automatic document feeder