Barcodes – more than lines

Do you know the picture of the cashier creates a price sticker for each individual item with a labelling-machine and sticks this sticker on the item? And then manually enter the information on it at the cash desk? It has to be easier? This is what Joseph Woodland and Bernhard Silver thought and so they committed to developing a more efficient solution in the form of lines an gaps in the 1950s.

On June 26, 1974 the time had finally come – on this day in Ohio (USA) an item (a piece of chewing gum packaging) was swiped over the cash register using a barcode.

Nowadays practically every cash register has a barcode reader and many products are labeled with a barcode. In addition this technology has also established in numerous other areas, such as logistics. Here barcodes are used to identify packaging, storage locations and for other applications.

Lines as a base

The well-known barcode is called 1D barcode. 1D codes are divided into numeric and alphanumeric codes or codes with and without a check digit. International standards are a key success factor for its widespread use. The barcode is defined in the international standard ISO/IEC 15420 and for example the content is limited to 0–9 characters. Other standards are EAN- (European Article Number) and UPC-Codes (European Universal Product Code).

A barcode reader measures and interprets the width of the dark lines and the light gaps between them. This can be done in a number of ways. With the so-called laser scanners the scanning is carried out by means of a laser beam, which is directed onto the barcode with a vibrating or oscillating mirror and measures its reflection. The cheaper CCD scanner follows a similar principle, in which the barcode is illuminated with a light-emitting diode instead of a laser.

From lines to squares

The information that can be encoded in a 1D barcode is limited to around 85 characters, as the barcode becomes wider as the number of characters increases. The 2D barcode was developed in order to be able to process more information with automatic reading devices. Probably the best-known example of a 2D barcode is the QR-code. Up to 4296 alphanumeric characters can be coded in this. Further examples are stack-codes, matrix-codes and data-matrix-codes.

In order to be able to read 2D barcodes it is not enough to capture the light and dark areas. So-called imagers are used for this purpose, which take an image of the barcode and the surrounding areas by a camera and then interpret it with the aid of a computer. Reading a 2D barcode is technically more complex and takes more time than reading a 1D barcode.


Aside from all the technical aspects companies should note that nowadays numerous consumers want to receive more and more information about the items they have bought. To make this possible the QR-code is usually used, which can be quickly read using modern smartphones and their cameras. For example, the website for the product can be called up directly with further useful details. And thanks to the tried and tested barcode the supermarket staff only needs one movement to enter the item. In short – 1D and 2D barcodes have become indispensable today.