Bar Code Reading: Should It Be Face-Up or Face-Down?
There has been much debate over the ideal way to read a bar code: in the context of an airport environment, should bar codes be read face-up using a periscopic design or face-down on a flat bed scanner?
During the development phase of Access' airport bar code imager and boarding gate reader range of products, the Access engineering team conducted a number of trials of an innovative face-up reading approach and compared the results with flat bed (face-down) scanning.
The trials included assessment in two key areas. First, the ease of operation for the user was considered, including use by airport agents and passengers.
Second, the speed and accuracy of bar code reading was assessed. This included bar codes from different media, including home printed documents and bar codes displayed on mobile phone screens, and different ambient lighting conditions.
The results were conclusive - the best way to read a bar code in an airport environment is face-up and the reasons are briefly set out below.
Access exclusively use face-up reading technology and, having introducing this approach in airports, has become the industry's market leader. If you would like to discuss the merits of the Access approach of face-up reading, or would like a demonstration to satisfy yourself, please do not hesitate to contact us.
Read an opinion piece written for the blog on Passenger Terminal Today website by clicking here
Benefits of Face-Up Bar Code Imaging
Agent can see the barcode being displayed during operation
When using Access devices the bar code is visible to the operator at all times. The target area on an Access imaging device is illuminated by a red glow making the positioning of the bar code in the reading zone straightforward and intuitive. On A4 home-printed documents, where the bar code may be printed anywhere over a large area of the document, this is particularly beneficial. In tests, the ease of positioning alone makes face-up reading technology significantly faster than the flat-bed approach.
Bar code reading is intuitive and easy for untrained users and passengers
Trials have established that Access readers are intuitive to use, minimising training time and operator delay. In addition, as increasing numbers of passengers use bar codes from their mobile phones and PDAs, operators are inviting the passengers to operate the reading device themselves where the intuitive nature of the device saves time.
When reading home-printed documents and printed bar codes, documents are intuitively handed to the agent face-up. Face-up reading means that the document does not need to be turned over to scan and then turned back to be handed back the the passenger, reducing the complexity of the reading operation. See further information below.
Bar code reading is not impeded by glare from lights
The reading head of Access bar code imagers provides a natural hood, blocking overhead glare and providing a more controlled light for bar code reading.
Excellent reading of barcodes from mobile phones & PDAs
For optimal reading, the back-light of a mobile device will need to be on. This can be verified with face-up reading. In addition, as face-up reading is contactless, there is no chance of accidental dialling, which would remove the bar code from the screen of the mobile device. In trials, it has been found that Access devices are particularly suited to reading a wide variety of mobile phones, particularly those used by the business passenger.
The imager mechanism is protected from spillage and transfer of dirt and ink
The imager is above the reading media and the operator. This protects the imager from spills, leaks, dirt or dust.
The viewing screen kept separate from media, reducing damage
Unlike flat-bed scanning, in normal operation the media does not make contact with any part of the reading device: the media is suspended in the reading zone. This lack of direct contact prevents the transfer of dirt and the accumulation of scratches, providing a consistently high bar code reading performance through the life of the product.
Disadvantages of Flat Bed Scanner Approach
Operator unable to ‘see’ barcode causing a delay in positioning the bar code correctly
With the bar code positioned face-down, the operator does not know with certainty the position of the bar code. This results in the wiping of the bar code in the approximate area of the reading zone until the bar code is read. For passengers using these devices in airports, any advantage as a result of familiarity of flat bed reading from using self checkout tills in stores, is more than outweighed by the slow operation and poor read rate also familiar to self checkout users.
Increased complexity of operation for the operator
Passengers instinctively offer the bar code facing upwards, whether on a mobile device or paper. The operator must, for every bar code read, turn the media over for reading and then back to return to the passenger. While a small effect for single read, over many operations, for example when boarding an aircraft, this can add time to the overall process. In trials by one of the major carriers in the US face-up and flat-bed scanners were compared side by side for aircraft boarding. Agents reported minor fatigue in their arms and wrists when using flat-bed scanners as a result of twisting their wrists over and back again in the process of bar code reading.
Viewing screen will accumulate scratches, adhesive & ink
When documents or mobile devices are read on a flat bed scanner there is typically physical contact. Over time this can result in the accumulation of dirt, which has to be periodically cleaned, or scratches that permanently damage the flat bed glass and potentially interfere with the devices long-term performance. This problem can be exacerbated as bar codes may be wiped around, trying to match the obscured bar code with the reading area of the scanner.
Accidental dialling of mobile phone
Flay-bed reading often results in the media making contact with the flat bed scanner's glass window. When using a mobile phone, this may cause accidental dialling resulting in the bar code being removed from the display. In addition, with the phone face down, the operator is unable to see whether the display back-light is on.
Susceptibility to glare from overhead lights
Without the protection of a hood, the flat bed reader is often exposed to overhead lighting, bright sunlight and changes of light, such as shadows caused by people passing by, which can trigger false reads or interfere with bar code reading. This problem may be exacerbated where certain translucent papers are used or when the flat bed is not completely covered, such as when mobile phones are read.
No protection to imager of liquid spills and damage
Unlike the face-down reader where the imager is hidden under a protective hood, the flat-bed scanner is and liable to spillage and accidental damage.