Unidirectional code for interactive map system

摘要

A system for plotting information on maps and reading information therefrom comprising maps which have machine-readable codes on the backs thereof arranged to indicate the coordinates of the map. A stylus is adapted to be moved over the map surface to read the map coordinates by sensing the codes thereon. The novel unidirectional codes comprising code bars all extending in the same direction, permit the use of simplified code sensing apparatus.