When a large format display is described as rated for 24/7 operation you might think that you are safe to run it all day long, every day of the week and without interruption. AV News finds out that it’s far from that simple. We look at the operating constraints and provide some insight into how to prolong the life of displays running long duty cycles.
As Large Format Displays (LFDs) replace other technologies in environments that operate around the clock, the issue of 24/7 operation has risen to the top of the agenda. The nub of the question is: what do we really mean by 24/7 operation?
Sharp has slightly put the cat among the pigeons with a statement to the effect that displays in the PN-E, PN-R, PN-U, PN-K321H and all its PN-V models are all capable of 24/7 operation – without constraints. Darren Gaffey, pan EU product planning manager for Sharp Electronics Europe says: “There are no specified operational constraints for the Sharp models rated for 24/7. These Sharp displays are guaranteed for 24/7 use for three years from switch on.”
This represents a clear differentiation from the position held by other major vendors, who point to the problem of ‘image retention’ which can occur in applications demand long duty cycles – particularly where a portion of the content shown on the display is static. Nico Kamffer, client services director at PSCo Technical Distribution, explains:
“The most important issue that 24/7 screens address is that of image retention or screen burn and robustness – depending on the technology being analysed, of course. This is the key consideration in the makeup of the panels where different liquid crystal (the LC in LCD!) material is required and the emphasis on controlling temperatures is much higher than with products that are not 24/7 rated. Warranty on professional displays is also a major consideration and needs more allowance due to the different, more expensive components or materials being used – hence the difference in cost between professional versus commercial displays.”
Real 24/7?
The requirement for actual ‘24/7’ operation is a relatively small niche, largely concentrated in transportation, control and monitoring, fuel stations and fast food restaurants. Thorsten Prsybyl, product manager at NEC Display Solutions Europe GmbH, has found that just 10% of the 24/7 capable displays are actually deployed in genuine 24/7 applications.
Prsybyl says that: “We have a lot of customers buying 24/7 capable products for other reasons than their 24/7 capability. Sometimes it is the higher brightness these screens provide or the more advanced features set those displays usually come with”.
Gaffey concurs: “Within the B2B market 40% of our sales are made up of professional models, the majority of which have 24/7 technology. Though we do have a high demand for consumer screens in business applications, 24/7 technology provides a clear differentiator between professional and consumer type displays providing additional reliability and robustness to the users, even if the application is not 24/7 critical.”
ROI
As in all applications for display technologies, choice of solution is dependent on Return on Investment (ROI) and Total Cost of Ownership (TCO) in addition to the specifications and operating environment. Kamffer says that these calculations must also take into account other factors including: whether or not the displays are used in a videowall; whether displays are in portrait or landscape orientation; and how they are mounted or enclosed.
Kamffer puts forward a hypothetical example to illustrate the point: “in some retail environments displays are expected to run for 20 -24 hours a day, often in videowall formation. The expected ROI in these circumstances is high and, more importantly, downtime has a big negative impact. If the displays are part of a project that is being financially written down over 2-3 years, the solution must be expected to last for at least the duration of the depreciation cycle.”
“By lasting,” says Kamffer, “I mean working to optimal specification according to the manufacturer’s guidelines and fully covered under warranty. If the display fails or degrades due to over usage then the complete system being used is not ‘earning its keep’ for the duration of the downtime, and this should be taken into account in assessing the financial return. This applies equally to most, if not all, vertical markets.”
In these demanding applications, where LFDs are operating the extremes, 24/7 screens will only perform to their full potential and achieve their specified service life if correctly installed and mounted in line with manufacturers’ specifications. It is essential to follow manufacturers’ guidelines for mounting specification. The correct brackets allow enough heat dissipation from the displays in both portrait and landscape deployments.
Selection
If you have followed the manufacturers’ specifications to the letter, used the correct mounts and carried out the installation with skilled and experienced staff, what can you reasonably expect to get out of a 24/7 display? Prsybyl says it is possible to get 24/7 continuous performance, but this will impact on the life of the product:
“NEC recommends turning the displays off every night for a few hours, if possible, especially when the content is of a static nature. If that is not possible, the customer needs to regard the display as consumable which needs to be replaced regularly, e.g. every 3 years. Such extreme situations are quite rare, though. Most customers can follow our guideline which can lead to other extremes where e.g. we have airports still using our LCD3000 – after 10 years.”
NEC has a set of operational guidelines that help customers prolong the life of their screens, and the company says that it has always been careful and open when it comes to 24/7 operation –“unlike some other brands in the market,” adds Prsybyl. “There are competitors promoting displays with TV electronics or TV back lights with as little as 350cd for 24/7 applications. This low brightness, which is insufficient for most public installations, will reduce to an unacceptable 250cd after 3 years of 24/7 operation,” he says.
Customer protection
Prsybyl believes that the best policy for a vendor is to employ an open communication policy and to refrain from promoting displays for 24/7 use which are not fit for purpose. Kamffer argues that the customer’s best protection is to seek expert advice and to rely only on experienced and qualified 24/7 installers. Samsung has gone as far as a City & Guilds course for partners installing its LFDs.
Jamie Blakemore, business development manager at Samsung Electronics UK explains: “The majority of partners successfully manage their own installation process; however Samsung has introduced a professional City & Guilds accreditation at the BMET College to educate clients and integrators on the correct and suggested setup and installation of large format displays. This is available to all our partners and clients. [For further information, please visit the website http://samsung.bmetc.ac.uk/content/samsung-digital-service-academy-12-months].
Prsybyl says, on behalf of NEC, that: “There is no guideline in terms of qualification of the installer. NEC has defined guidelines for the way the displays should be used with content design guidelines”. (See the box below.)
Applications
As discussed earlier, customers buy 24/7 LFDs for a variety of reasons, Samsung says that around 35% of its display sales in the UK have 24/7 capabilities (the DE, UD, LE and PE ranges) but these are not bought for their 24/7 applications alone. The market is growing quickly as more customers like to have the comfort and flexibility of using displays for a range of purposes.
The common factor in these customers’ requirements is the need to provide a constant flow of information to the screen over a long duty cycle, although not always 24/7. Samsung says its displays provide enhanced functionality aligned to specific business needs. Reliability and performance are important, as many displays are a source of revenue from advertising for the customer. There is often an ROI expectation in this style of application, so displays have to be reliable and fit for purpose.
But if your customer’s application calls for displays operating the extremes of the specification you would be well advised to take the advice in the box below – or you could explore the Sharp offer.
