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Barcode Scanners

One of the great things about barcodes is that they have a great deal of built in redundancy. Because the information is stored in a series of vertical lines, parts of the label code can be obscured of destroyed, yet still be read by a scanner. Also, barcode are scalable to many sizes. The width of the lines in a barcode is not the determining factor in what information it carries. Instead, it is the proportion of the white spaces to the black lines that makes the difference. This allows barcodes to be scaled to any size without any data corruption.

Barcode scanners all work by the same principle. A light source is shined onto the barcode and reflected back to the scanner where the light is analysed and the series of 1s and 0s is detected and transmitted to the computer for decoding. There are several kinds of barcode scanners that are primarily differentiated by their light source and their method of scanning. These include pen or wand scanners, hand held scanners, and fixed position scanners.

Introduction to barcodes

Since the mid 1970s, barcode labels have been part of our everyday lives. These labels are attached or printed on almost all consumer goods and are used in a wide range of industries. Shipping and transportation companies use barcodes to keep track of inventory and packages while businesses like the entertainment industry uses them to keep track of ticket sales. Barcodes are used in almost any application that requires keeping track of a lot of items at once because of their speed and accuracy. But, the barcode would be of very little use without a device that can interpret the seemingly random pattern of lines and spaces. This is where the barcode scanner comes into play. Barcode scanners are an integral part of barcode technology and largely responsible for the success of the barcode itself.

A Brief History of the Barcode

In the United States during the late 1940s, industry leaders in the grocery business were seeking out methods to improve efficiency and to gather information about public shopping habits. They wanted to be able to keep track of their inventory and how it could be arranged in the store for better sales. Two graduate students named Joseph Woodland and Bernard Silver attempted to answer this problem by proposing the use of invisible dyes that could be seen under ultraviolet light. Their work hit a stumbling block when it became apparent that this method was expensive and inefficient, making it impossible for industry to adopt.

They soon began to investigate other methods of coding products including techniques based on Morse code, which is based on a series of dots and dashes when written on paper. Woodland discovered that if he were to extend each individual dot and dash to form a pattern thick and thin vertical lines, he might have found a solution to the grocery inventory problem. Eventually Woodland and Silver were issues a patent for the barcode and scanner device.

Initially, instead of being used in grocery stores, barcodes and scanners were used to keep track of freight cars in the train industry. Unfortunately, trains tended to bounce a little bit as they moved along the tracks, making bar code scanners unreliable at best. When the Universal Product Code (UPC) became introduced in the 1970s and barcode scanners had become more refined, the use of barcodes and optical readers became widespread, leading to their universal presence in today's world.

How Barcodes Work

Barcodes are a series of thin and thick vertical lines in the case of one dimensional barcodes or a pattern of geometric patterns as seen in two dimensional barcodes. A barcode reader interprets the pattern of white space and black printing and converts them into a series of 1s and 0s -- binary code. A computer then converts the binary code into text or information that is usable by humans.


Barcode scanners have come a long way from their humble beginnings and are available in a number of options and interfaces. Selecting a scanner should be done based on needs and the type of code being scanned. As technology progresses, more sophisticated barcodes are sure to be introduced along with new types of barcode scanners.