Systems for recognizing printed text and images originated in the late 1950s and have been in widespread use on desktop computers since the early 1990s. Examples of such reading tools include bar code technology, optical character recognition, optical mark readers, and "smart card" technology.

Bar Code Technology

A bar code is a printed series of black parallel bars or lines of varying width on a white background that is used for entering data into a computer system. The bars represent the binary digits 0 and 1, sequences of which, in turn, can represent numbers from 0 to 9. The numbers presented by a bar code are also printed out at its base. Bar code information is read by an optical scanner such as a handheld "wand" or a bar code pen that is moved across the code or vice versa. The computer then stores or immediately processes the...