Videowall and LED screens Buyer's Guide analysis: Applications call the tune

Things used to be simpler. Indoors, events producers stacked videowall 'cubes' – long boxes with a projector at one end and a screen at the other – to create large displays. Outdoors, they used devices such as Sony Jumbotron or, later, LED displays made up from multiple panels. But that was at least a decade ago. Now, there are many more technical options available for use in the videowall/large screen display market.

Conventional, stackable videowall cubes (mostly with LCD or DLP projects and mirrors to fold the projection path and make them more compact) are still available. Rigs using multiple projectors and mirrors are in common use. Flat screen displays with very narrow bezels can be mounted together to form a large, but very thin, indoor videowall. Indoor LED panels using high resolution displays are becoming increasingly available and affordable, while very large screen LED displays at resolutions ranging from 4mm to 25mm or 35mm are being used everywhere – in shop windows, on transportation systems, in tv studios and at sporting events.

And development hasn't stopped. This year's ISE show saw the launch of cheaper and lighter indoor LED screens such as the Nanolumens offering and the first showing of production versions of genuinely new technology screens such as the Mitsubishi large screen OLED display and Prysm's laser phosphor display (LPD) technology. Christie's stackable MicroTiles system – in principle, a small videowall cube – was also much in evidence and, a year after launch, it is being used in serious commercial applications.

As well as changes in technology, different application sectors now have clear requirements of their own. For example, the control room market, digital signage, public display, rock concerts and sports venues now have individual 'takes' on the technology that is right for them.


There's still a place for videowall cubes with a projector in the back and a screen on the front but the main market for such products in now in control rooms which require very high resolution displays (up to UXGA or above) and can be operated 24×7 with very low failure rates and long periods between lamp changes. Front access via a hinged screen is usually provided for maintenance purposes.

Rear projection (RP) cubes developed for the needs of the control room market also feature sophisticated electronic set-up software to manage colour balance and brightness across the videowall. They use image processing and switching to manage the supply of different information (such as the images from traffic or surveillance cameras) to different 'windows' on the wall.

RP systems are also extensively used as a tv news studio backdrop but the more sophisticated broadcasters usually use a multi-projector rig on a seamless screen, rather than cubes. In this application, key requirements include colour and brightness/contrast balance between screens as well as very accurate picture alignment.