How do barcodes and barcode scanners work?

Barcodes and barcode scanners stand as the most widely used tools for product identification across the world and play a key role in the operation and effectiveness of many organisations, especially those in industries like retail, warehousing, and logistics. 

Barcodes allow for faster reading of encoded information, and they are used in all places – on gift cards, in courier shipments, on prescriptions, in company information transfer registers and elsewhere where identification is used in the system. 

Barcode scanners are some of many devices that read barcodes. These devices can quickly scan barcodes and all data can be easily transferred to the system within seconds.

This blog will give you an overview of how to read a barcode, how barcodes and barcode scanners work, and the types of barcode scanners. The information included here will help you understand how useful barcodes and barcode scanners are and how quickly they can simplify your work.

Read on to learn more about:

Table of contents

1. What are barcodes used for?
2. How do barcodes work?
3. How to read a barcode
4. What is a barcode scanner?
5. How does a barcode scanner work?
6. Types of barcode scanner

What are barcodes used for?

Barcodes are used for identifying products, tracking inventory, and managing prices. They are deployed in warehouses to track shipments, in retail stores as part of the purchasing process, in post offices to indicate the place of delivery, and in other places.

How do barcodes work?

Barcodes work by encoding data in a visual pattern that can be easily scanned and interpreted by barcode reader equipment, or a smartphone equipped with a barcode scanning app. Scanners will convert the bar pattern into a line of text that contains details about a given product.

Here's a simple breakdown of how data gets encoded into barcodes:

1. Choosing a barcode type: Imagine you want to create a barcode for a product. First, you pick the right type of barcode. Each type has its own rules for how to turn information into lines and spaces.
   
   
2. Assigning numbers and letters: Next, you decide what information you want to encode. It could be numbers, letters, or a combination. 
   
   
3. Making the barcode: Now, you use a computer program or machine to turn your information into a barcode.
   
   
4. Printing the barcode: Once your barcode is made, you print it onto labels or packaging for your product. 
   
   
5. Scanning the barcode: To read the barcode, you use a scanner or a smartphone app. The scanner takes a picture of the barcode and then decodes it, and translates it back into numbers and letters.
   
   
6. Getting the information: The scanner reveals the message encoded in the barcode. It might be a product code, a price, or other details about the item.

How to read a barcode

Linear barcodes, with their vertical lines of varying widths, can be deciphered by the human eye if you understand the significance of the black and white lines along with accompanying numbers. Each line represents a specific sequence of data, typically corresponding to product information or identification numbers.

In contrast, 2D barcodes, such as QR codes, employ a more intricate pattern of squares, dots, or other geometric shapes arranged in a two-dimensional grid. The complexity and density of these patterns exceed the capabilities of human visual perception. Barcode scanners equipped with advanced imaging technology are required to accurately capture and decode the data contained within 2D barcodes; by the same token, 2D barcode or QR code printers offer enhanced printing quality for optimal accuracy.

Here's a breakdown of how to read a linear barcode and what the lines and numbers mean:

1. Start and stop characters: Linear barcodes begin and end with special characters called start and stop characters. These characters indicate the beginning and end of the barcode to the scanner.
   
   
2. Quiet zones: Before and after the barcode, there are quiet zones, which are blank spaces that ensure accurate scanning. These zones help the scanner to differentiate between the barcode and surrounding elements, reducing the risk of misreads.
   
   
3. Bars and spaces: The main part of the barcode consists of a series of bars and spaces. The width and arrangement of these bars and spaces encode the data represented by the barcode.
   
   
4. Encoding data: Each specific combination of bars and spaces corresponds to a character or a set of characters. Different barcode symbologies (such as UPC, EAN, Code 39, etc.) use different methods to encode data. For example, in UPC barcodes commonly found on retail products, each digit from 0 to 9 is represented by a unique pattern of bars and spaces.
   
   
5. Check digit: Many linear barcodes include a check digit at the end. This digit is calculated based on the other characters in the barcode and serves as a form of error detection. When the barcode is scanned, the scanning device verifies that the check digit matches the calculated value, helping to ensure the accuracy of the scanned data.

Example of how to read a barcode

To illustrate how to read a barcode, let's use an example:

Each digit from 0 to 9 in the barcode is symbolised by a specific pattern consisting of 7 lines. 

These patterns are designed according to a predetermined sequence:

0 = 3211  5 = 1231

1 = 2221  6 = 1114

2 = 2122  7 = 1312

3 = 1411  8 = 1213

4 = 1132  9 = 3112

The sum of the numbers is always 7 for each single code, e.g.: 6 represented as 1114 (1 + 1+ 1 + 4 = 7)

The barcode depicted in the image, with its initial two digits being 0 and 1, would commence with "10132112221". Breaking down this sequence, "101" serves as the barcode's start marker, while "3211" represents the digit 0 and "2221" represents the digit 1. This structured interpretation guides the reader through the barcode's beginning, decoding the subsequent digits accurately.

What is a barcode scanner?

A barcode scanner is a device used to capture and interpret data stored in barcode symbols printed on labels or products. It emits light onto the barcode, detects the reflected light with a sensor, and interprets the pattern of bars to decode information such as product numbers or serial codes. This data is then transmitted to a connected device for processing. 

But how do barcode scanners work exactly? Read on to find out.

How does a barcode scanner work?

A barcode scanner works by shining a beam of light over the barcode, then it checks out how the light bounces back. This process turns light energy into electrical energy inside the scanner. The decoder within the scanner interprets these electrical signals and turns them into readable data. This decoded data is transmitted to a computer or other connected device.

Here’s how barcode scanning happens step by step:

1. The scanner sends out light onto the barcode using cameras, sensors, or LED lights, depending on what kind of scanner it is.
2. The light reflected from the barcode is detected by a photoelectric cell within the scanner.
3. As the scanner moves across the barcode, the photoelectric cell generates on-off pulses that match the black and white stripes of the barcode.
4. Inside the scanner an electronic circuit converts these pulses into numbers.
5. The numbers are then transmitted to the connected computer system, where they are recognised and processed as barcode data.

Types of barcode scanner

When choosing a barcode scanner, it's important to think about what you’ll be using it for and how it helps you get the job done.

There are various types of barcode scanners to choose from: laser scanners, image scanners, Bluetooth scanners, fixed scanners, and also mobile computers with a built-in barcode scanner. Each type is designed for different situations and tasks, so you can find one that fits right for your needs.

Explore our complete range of barcode scanners here or read on to find out more about each type.

1D barcode scanners

These scanners are designed to read 1D or linear barcodes. Among them, 1D laser barcode scanners are the most used, often resembling a "gun" in their model design. They can operate effectively without direct contact with the barcode but generally require proximity within a range of 4 to 24 inches to scan accurately. The Zebra LS2208 is a bestseller in our range of 1D barcode scanners.

Zebra LS2208 Handheld 1D Laser Barcode Scanner

2D barcode scanners

These scanners are capable of reading 2D barcodes, that is, images containing dots, squares, rectangles, and hexagons. 2D barcodes can store much more complex data than linear codes and enable the encryption of information such as web addresses, text, images, and coupons in camera-readable formats. 2D barcode scanners have the capability to scan those barcodes, like QR codes, as well as 1D barcodes. One of our bestselling 2D barcode scanners is Zebra DS2208, especially recommended for retail.

Zebra DS2208 Corded Handheld 1D/2D Imager Barcode Scanner (DS2200 Series)

Bluetooth barcode scanners

Wireless barcode scanners offer mobility and flexibility by enabling scanning on the move, utilising either Wi-Fi 802.11a/b/g/n or Bluetooth technology. These scanners can connect to a range of devices, including computers, smartphones, forklift trucks, or tablets. Equipped with integrated processors and memory, they can function independently of a host device. This provides users with the freedom of movement and the ability to serve customers wherever they may be. Our bestseller among the Bluetooth scanners is the Zebra LI4278 imager.

Zebra LI4278 General Purpose Cordless Linear Imager 1D Barcode Scanner

Fixed barcode scanners

Fixed mount barcode scanners provide top-notch, hands-free scanning perfect for tight spaces. They are very easy to set up, seamlessly blending into your workflow while keeping things moving fast and smooth. The Datalogic Gryphon I GFS4400 fixed scanner is one of our top sellers in the range.

Datalogic Gryphon I GFS4400 2D Fixed Mount Barcode Reader

Mobile computers with built-in barcode scanners

Mobile computers with built-in barcode scanners combine the functionality of traditional computing devices with the ability to scan barcodes on the go. Equipped with integrated barcode scanning technology, typically through a built-in camera or dedicated scanner module, these devices provide businesses and organisations with a convenient and efficient means of capturing and processing data in mobile environments. The Zebra TC21 Mobile Computer is our bestseller in the range. 

Zebra TC21 Durable Wi-Fi Android Mobile Computer

Find your next barcode scanner at The Barcode Warehouse

From warehouses to grocery stores, barcodes and barcode scanners are indispensable tools that power modern commerce. This blog has provided insights into the purpose and mechanics behind these technologies. You now know how barcode scanners work, from laser scanners to image scanners, and also how barcodes facilitate data encoding and decoding.

Whether for commercial or non-commercial applications, at The Barcode Warehouse we respond to the diverse needs of companies that use barcodes and scanners daily. We offer a wide range of scanners – browse our selection of barcode scanners or get in touch for friendly expert advice.