Bar code and reading and decoding device

Abstract

A trinary bar code and a device for reading and decoding said bar code are described. A predetermined number of bar code elements on a substrate makes up each character of data. Each bar code element is selected from a group comprising a first element in the form of a bar having a first length, a different sensibility than the substrate, and a given width; a second element in the form of a bar having a different length than said first element, a different sensibility than said substrate, and a width substantially the same as said given width; and a third element in the form of a space having a width substantially the same as said given width and having the sensible characteristic of said background. The device for reading and decoding the bar code includes a plurality of sensors, a corresponding plurality of flip flops to which the sensors are coupled, gates connected to the flip flops to provide combinations of signals from the flip flops, a group of latches coupled to the gates and equal in number to the number of bar code elements per character, a control circuit to cause the latches sequentially to store data corresponding to the sequential sensing of the bar code elements; and a decoding circuit coupled to the latches to decode the latched data to output the encoded character.