LEDs can be used to replace fluorescent tubes in advertising poster boxes, offering long-term savings in energy and maintenance costs, which are set against the higher up-front cost of the LED system, explains MATTHIAS SCHMIDER.
The lightbox, widely used for advertising displays and in decorative lighting, is simple, relatively cost-effective and easy to design and manufacture. Traditionally, the focus of poster-box manufacturers’ engineering efforts has been on producing metal frames in various shapes and sizes. The light source was an apparently trivial issue: conventional poster boxes use T5 or T8 fluorescent tubes, which have the advantage of being both inexpensive and technically simple. The main challenge is to produce an evenly-illuminated surface: this is a matter of adjusting the depth of the metal frame to allow sufficient room for light diffusion. Why use LEDs? By implementing an LED-based design, the poster-box manufacturer can offer customers important environmental, performance and financial benefits. A comparison of fluorescent tubes with advanced power LEDs, such as the Luxeon Rebel range of devices from Philips Lumileds, will show that an LED array uses less power (meaning a reduced carbon footprint) and has a longer operating life than fluorescent tubes producing equivalent luminance. LED-based lighting also performs better in cold conditions, while fluorescent tubes perform poorly in the cold. Overall, LED-based poster boxes promise lower energy costs, lower repair and maintenance costs, and less downtime. This last point is particularly important for advertising applications – a poster box with a failed or flickering fluorescent tube is of no value to an advertiser. And while end-of-life disposal of fluorescent tubes is problematic, because they contain hazardous materials, the materials in LED systems are much more environmentally benign (although subject to the provisions of various waste directives). Every manufacturer will of course make their own economic calculation to determine the value of switching to LED technology. However, the combination of more reliable operation, lower maintenance costs and lower energy costs certainly has the potential to outweigh the higher initial bill-of-materials (BoM) cost of an LED system. **This article was published in the July/August 2011 issue of LEDs Magazine.**