Barcode scanner: the logistic superweapon for goods handling and modern production processes
Barcodes have revolutionized the way large quantities of goods and automated production processes are handled. In retail, too, the introduction of barcodes has made goods handling much easier. To the chagrin of many retailers, the technology behind it is not that easy to grasp. There are many different codes, readers and aspects of action that you should be familiar with to form an informed opinion about your own needs.
This is how barcode scanners work.
From a technical point of view, barcode scanners work like all other scanning options (e.g. flatbed scanners): The surface of the object to be scanned is illuminated, and sensors detect the optical differences within the barcode (light/dark). Conversion software then generates the stored information from the raw data that has been readout.
The different barcode types – explained briefly and concisely
EAN 8 / EAN 13 – barcode for retail.
You come across this barcode during normal shopping in supermarkets. It is used to uniquely identify a wide variety of commercial goods and automatically settle them at cash registers.
Code 39 (3 of 9) – The alphanumeric barcode.
Unlike the normal EAN code, this extended code can contain a combination of special characters, numbers and letters. This Code 39 can be recognized by its start and stop characters, symbolized by an *. There are two different Code 39 variants:
- Standard Code 39: Only the digits 0-9, capital letters and the special characters / $ can be used. -% and + are used.
- Extended Code 39: This extended code (Code 39 Extended) can represent the complete ASCII character set.
2/5 I (2 out of 5 interleaved) – numeric barcode.
This barcode is mainly found in industrial areas and forwarding logistics. Due to its structural design (both lines and gaps convey information), this code can be applied to minimal surfaces. Only the numbers 0-9 are used.
Code 128 – high-density alphanumeric bar code.
The barcode 128 is mainly used in delivery services (DPD, UPS, DHL, etc.) and used in the industrial sector. There are 3 basic groupings for this type of barcode:
- Code 128 A: Parts of the ASCII character set are used (lower case letters are not used).
- Code 128 B: All parts of the ASCII character set are used.
- Code 128 C: Only the digits 0-9 are used (very space-saving, as only a small width is required).
EAN 128 barcode
This barcode can only be found in retail logistics and can be provided with specific data content that significantly exceeds the possible data volume of the aforementioned barcode types.
Different areas of application in which barcodes are used
The range of possible uses for barcodes is extensive. These codes are most commonly used in the following areas.
Barcodes in automated manufacturing processes
In industrial production, barcodes are used to control automated production processes correctly. Where otherwise human workers would be necessary to control or initiate the various production parts and production steps, this is done by a sophisticated, automated system. For this purpose, the production parts are provided with a barcode, which is automatically read out at each relevant point and assigned to the next production step.
Use of barcodes at supermarket checkouts
Image: Barcode scanners are already permanently installed at the checkout in most supermarkets. Image Source: Aleph Studio – 304624157 / Shutterstock.com
The permanently installed barcode readers at the supermarket checkouts are omnipresent. The light that is emitted by the laser is reflected by the ingenious structure. A photodiode detects the reflected light and evaluates the information sent. Due to the alignment of the laser beams, the distance to the scanned object can be relatively large. The technology used is called an omnidirectional laser scanner. With this structure, objects can be dragged over the scan area without the alignment of the barcode having to be as exact as possible to the scanner.
Unlike supermarkets, a hand scanner is usually used in retail to read the barcodes at the checkout. With this type of laser scanner, the barcode must be held as precisely as possible at a 90 ° angle to the hand scanner – and the distance must not be too large or too small. The underlying technology is known as linear laser technology.
Barcodes in inventory management & warehousing
Before the development and use of barcodes, inventory management and warehousing were rather cumbersome. Using long lists on paper, the inventory had to be compared with the incoming and outgoing goods. With the introduction of the barcodes, the entire warehousing could be implemented with EDP support. This resulted in enormous advantages for every company that runs a warehouse. These advantages have had an impact on the following points in particular:
- Incoming and outgoing goods
- When incoming and outgoing goods are received, the goods are scanned using the existing barcode using a hand scanner. Due to the electronic processing, the inventory in the inventory management system is updated immediately, and access is immediately visible to every employee. In outgoing goods, it is exactly the opposite: every outgoing good are recorded in the EDP immediately after the barcode has been scanned, which reduces the inventory.
- Permanent inventory control
- The use of barcodes in incoming and outgoing goods enables permanent inventory control. This means that sales staff can see at any time which goods are still in stock and which have to be reordered. The inventory control is also helpful with the prescribed inventory: a target list is available and can be compared with the manually controlled actual status. In this way, for example, theft can be proven.
Use of barcodes in the mail order
The use of barcodes and mobile hand-held scanners is common practice in the mail order business. This offers decisive advantages for both the sender and the recipient of the goods.
The mail-order company can use the IT-supported inventory management of each article at any time to see exactly which articles are still in stock and which articles must be reordered. With a connection of the merchandise management system with, for example, an online shop, every buyer can also see whether an item is currently available or sold out.
- Location determination & shipment tracking of sent goods
- The location of goods that have already been sent can be easily implemented using barcodes. Depending on which method is used, the location of the goods can be displayed fairly precisely. With each acquisition scan, the location can be updated and displayed. This mainly serves the buyers who are waiting for their parcel. Mail-order companies have the option of responding to inquiries and complaints from customers by contacting the transport service provider via the IT-supported location of the goods.
Different techniques from the point of view of users
Depending on the area of application and requirements, different scanning techniques are used, which differ significantly in their handling and, above all, in the purchase price. The most common techniques are briefly explained below.
Image: Radio scanners are mostly used in larger storage rooms. Image Source: Dmitry Kalinovsky – 412786765 / Shutterstock.com
Wireless scanners are used wherever goods and parcels have to be sorted and put together in larger halls. The hand-held scanners, which are used as radio scanners, connect wirelessly to a central receiver that evaluates the scanned data. The range of modern radio scanners is between 15m and 70m, depending on the model and area.
LED scanners, also called CCD scanners, read barcodes using a light-emitting diode (LED). The detection sensor is usually a strip in the reader equipped with light-sensitive cells (CCD). For technical reasons, LED scanners only have a limited reading area in which the barcodes can be read out without errors. This area is between 10 cm and 50 cm away from the sensor bar.
With this technique, the bar codes are scanned using a laser beam guided over a movable mirror. Although this technique is more prone to failure than the two previous techniques, it is widely used. Scanners of this type can be found primarily in the form of built-in scanners that are used at supermarket checkouts.
Camera scanners work similarly to LED scanners but are equipped with significantly more sensor lines. According to their structure, camera scanners are very similar in their capabilities to a black and white camera. Unlike the previous scanners, camera scanners can also read barcodes that are upside down. Thanks to their ability to read modern QR codes, their frequency of use is increasing sharply. Most modern smartphones can read barcodes and QR codes due to the built-in camera.
Image: Most smartphones can now read QR codes thanks to their built-in cameras. Image Source: Bloomicon – 105635744 / Shutterstock.com
Regardless of the recording technology used, there is different hardware to cover as many application areas as possible. The various reading devices are briefly presented below.
Hand scanners transmit the recorded data either wirelessly or using a cable connection. The hand-held device is roughly similar to the structure of a pistol. They are usually used in retail and for larger warehouses.
This scanning technique is used in hand-held scanners
- Camera capture
- LED detection
- Laser detection
Cell phone scanner
A mobile phone scanner is nothing more than a smartphone that can read and display barcodes via an app and an integrated camera. From a technical point of view, the mobile phone scanner works via camera capture, with which both one and two-dimensional barcodes can be captured.
2D scanners illuminate the barcode by throwing LED light onto the barcode. The digital image only becomes visible when the captured code has been converted. During the conversion, the 2D scanner translates all information in the barcode and makes it interpretable for the user. The advantage of 2D scanners is their versatility – they can read not only one-dimensional barcodes but also two-dimensional ones.
Swipe readers are mainly used for entry and exit control but also for recording working hours. The reading unit is permanently mounted, which greatly favours reliable code detection. For a swipe reader to do its job, the barcode must either be printed on paper or a plastic card (bank card). To trigger the reading process, this printed barcode only needs to be swiped through the swipe reader.
The reading pen for capturing information from barcodes is a technology that is getting on in years. In size and shape, it is reminiscent of a ballpoint pen, the tip of which has to be swept over the barcode to capture the information. Due to the relatively high error rate, the reading pen is only used when there is no space for other techniques.
A built-in scanner is always used when the reader is permanently installed. This type of scanner is most often found in supermarkets, where barcodes have to be read at a relatively high speed (cash register system). CCD technology is mainly used for this type of built-in scanner.
- CCD technology in the built-in scanner
- With CCD scanners, the barcode to be read is illuminated by a permanently installed lamp. The reflected light is split up into different light spectra by a mirror system, whereby the colours blue, green and red become visible. The information made visibly is read out using sensor lines, with each sensor line being intended for a single colour. Built-in scanners with CCD technology are particularly robust, fast and less prone to failure.
Software scanners are used wherever no special hardware is to be used. Information is recorded, for example, via a camera built into the smartphone equipped with the appropriate software.
The previously known barcode has not been replaced with the QR code, but it has been supplemented very sensibly. The changed arrangement of the data creates a machine-readable code that can contain up to 1,800 characters in encrypted form. A big advantage of this code arrangement is the enormous error tolerance – up to 50% of the visible QR code can be destroyed without affecting the wealth of information.
2D data matrix
The 2D data matrix is a further development of the QR code. It enables 1,800 characters or 3,000 digits to be accommodated, which means that a large amount of data can be accommodated in the smallest spaces. The error tolerance for damaged code imprints is a good 25% so that even greater damage to the imprinted code does not make the data illegible.