Image scanning in the context of Memory card

A Nipkow disk (sometimes Anglicized as Nipkov disk; patented in 1884), also known as scanning disk, is a mechanical, rotating, geometrically operating image scanning device, patented by Paul Gottlieb Nipkow in Berlin. This scanning disk was a fundamental component in mechanical television, and thus the first televisions, through the 1920s and 1930s.

Microprinting is the production of recognizable patterns or characters in a printed medium at a scale that typically requires magnification to read with the naked eye. To the unaided eye, the text may appear as a solid line. Attempts to reproduce by methods of photocopy, image scanning, or pantograph typically translate as a dotted or solid line, unless the reproduction method can identify and recreate patterns to such scale. Microprint is predominantly used as an anti-counterfeiting technique, due to its inability to be easily reproduced by widespread digital methods.

While microphotography precedes microprint, microprint was significantly influenced by Albert Boni in 1934 when he was inspired by his friend, writer and editor Manuel Komroff, who was showing his experimentations related to the enlarging of photographs. It occurred to Boni that if he could reduce rather than enlarge photographs, this technology might enable publication companies and libraries to access much greater quantities of data at a minimum cost of material and storage space. Over the following decade, Boni worked to develop microprint, a micro-opaque process in which pages were photographed using 35mm microfilm and printed on cards using offset lithography. (U.S. patent 2260551A, U.S. patent 2260552A) This process proved to produce a 6" by 9" index card that stored 100 pages of text from the normal-sized publications he was reproducing. Boni began the Readex Microprint company to produce and license this technology. He also published an article A Guide to the Literature of Photography and Related Subjects (1943), which appeared in a supplemental 18th issue of the Photo-Lab Index.

In multifunction or all-in-one printers, fax machines, photocopiers and scanners, 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 scan, and thereby copy, print, or fax, 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.