Barcelona airport billboards use LED backlighting

Oct. 29, 2008
Uniform light distribution, low power consumption and reduced maintenance requirements are key attributes of using LEDs to backlight billboards.
Five large billboards, each measuring 4m high by 3m tall, have been installed at Barcelona airport by Sakma, a local manufacturer. The billboards use an array of LEDs, rather than fluorescent lamps, to achieve uniform lighting with much lower operating costs.

The customer for the project was advertising agency JCDecaux, representing AENA (the Spanish Public Airports authority).

JCDecaux challenged Sakma to build 5 billboards with a perfect and homogeneous light, with a dramatic cost reduction in service and maintenance. The agency required a direct energy cost saving via lower power consumption, as well as the use of environmental friendly, lead- and mercury-free technology. A further consideration is that the airport is open 24hours per day, all year long.

Billboard lighting has traditionally used fluorescent lamps, which results in an efficient system. However, fluorescent lamps have a low MTBF (mean time between failure). In a billboard where a large quantity of fluorescent tubes are used, the failure of just one tube causes a dark spot in the lighting and damages brand awareness for the advertiser. To avoid that problem, a constant and permanent service of signs is required.

Sakma’s solution was to use LED backlight pads measuring 21 x 32 cm, to provide a flexible and modular system, specially designed to build large illuminated surfaces with a completely uniform and homogenous light. With this system, any size can be reached just by installing all boards side by side and connecting them together with a gold plated pin connector.

Mounted into a slim frame, a distance of only 4 cm is required between the LED pads and the picture to have a perfect distribution of the light without any spots or shadows. The overall frame thickness, including back reinforcement, is 10 cm.

Also, say Sakma, power consumption is dramatically reduced due to the use of highly efficient LED technology. The billboards consume only 57 W at 24 V per 1 m2. Apart from the direct energy saving, low heat emission reduces expenses on air conditioning costs. The system has a long lifetime and is virtually free of maintenance, adding to the overall cost efficiency.