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Understanding Barcodes


The first barcode was invented back in 1951 in the US by Norman Joseph Woodland and Bernard Silver. But it wasn’t until 1979 that a barcode scanner was used for the first time in the UK! In 2011 Joe Woodland and the late Bernard Silver are inducted into the National Inventors Hall of Fame in recognition of their brilliant invention.


We all recognise them, but what actually are they, what do they do and how do they work?


What are are barcodes & what do they do?

Well, the short and simple answer is that a barcode is a machine readable graphical representation of data that can be captured by a computer. Barcodes are most often seen on packaging they are also used for many other business applications, such as tracking products and managing stock levels.


There are different types of barcodes depending on the kind of data they store and how they are used. The type of code you use depends on what you want it to do. If you are using a code on retail stores for example it will need to ne UPC/EAN, whereas factories tend to use Code 128, asset management commonly uses Code 39 and marketing and payment gateways use QR codes.


Barcodes are split into 1D and 2D


1D barcodes (singular dimension) such as a standard UPC barcode use lines and spaces and can hold about 20-30 alphanumeric characters of information and only operates in one dimension (horizontally). A 1D barcode uses binary coding. Each digit in the product number is given its own amount of horizontal space, which is exactly 7 units – so each number from 0 to 9 has a different pattern of white and black lines.


2D barcodes (two dimensional) such as QR codes use rectangles, hexagons , dost and other patterns and can store over 7000 data elements. They operate in two dimensions (horizontal and vertically). A 2D code uses four standardises coding modes (numeric, alphanumeric, byte/binary, and kanji) Visually the code consists of black (usually) squares arranged in a square grid on a white background


How do barcodes work?

There’s 3 integral parts to any barcodes usability:

1) The barcode itself

2) The scanner that reads the barcode and links back to the central computer.

3) The central computer running the database with all of the information.


The different widths and spaces in a barcode represent different numbers and letters that’s can be de-coded by a scanner


The scanner device shines light onto the barcode, the light reflects back off the barcode (black areas are absorbed and white reflected). The scanner generates a pattern of on/off pulses from the light (black = off/zero, white = on/one) These pulses are converted into binary digits (zeros & ones) by an electronic circuit attached to the scanner.


The binary digits are then sent to a computer (via Bluetooth, wireless network or directly attached to the scanner) which detects the code and identifies the item from a database.


Types of Scanner

LED scanners – usually a wand or pen shape and shine red LED light onto the black and white barcode pattern and then read the pattern of reflected light with a light-sensitive CCD or a string of photoelectric cells. A pen scanner needs to be run it across the barcode so it can reach each block of black or white in turn; with a wand scanner, the CCD or photocells read the entire code at once.


Laser Scanner – These are usually built into the base of the checkout lane, under a piece of glass, and you may be able to see the laser beam being bounced around at high-speed by a spinning wheel so it reads products (literally) in a flash.


Camera – A camera takes an instant photograph of the barcode. A computer then analyses the photograph, picking out only the barcode part of it and converting the pattern of black and white bars into a number. Mobile phones work this way to scan QR codes.


Barcode scanning technology only really caught on in the 1980s and 1990s after stores started to invest in computerised electronic point-of-sale (EPOS) checkout terminals. Since then, prices have dropped considerably making barcode systems affordable for even the smallest of businesses.