Digital Signage: Taking messaging outdoors

by all | 30 March 2015 10:57 am

By David Dumouchel
Outdoor digital signage systems are not very common yet in North America, but they are currently 
all the rage in Europe, as the technology has matured enough that they can be deployed in all sorts of environmental conditions and connect with wireless communications networks. They can offer sophisticated interactivity, wireless-fidelity (Wi-Fi) hot spots and wayfinding services.

Consider this scenario: a tourist visits Montreal for the first time and, while approaching his hotel in a taxi, realizes he has forgotten to bring along his travel guide to the city. Fortunately, just outside the hotel, he sees a digital ‘totem’—a street furniture component that displays information in a public area—and approaches it for further information. 
A touch screen features a map, including the main tourist attractions and shopping centres nearby. Instructions show how to download this map to his smartphone, thanks to an integrated computer. Other content includes listings of nearby restaurants, classified according to the style of their cuisine, and ads for local businesses, updated in real time. The tourist can buy and print a ticket for a live show that very evening.

All of the technology behind such an ‘information hub’ scenario already exists. And a network of totems can be linked to 
a single control centre and managed by just one or two employees, allowing the city 
to easily communicate with the public. Interactivity and live update capabilities, 
in particular, make these systems attractive for public officials and businesses alike.

From static to digital to dynamic
Today, most street furniture in North America is static and requires a lot of time and effort to update. There is 
a major opportunity, everywhere from tourist areas to sports venues to transit stations to commercial centres, to evolve to the next generation of outdoor signage and join other media in the shift from static to dynamic, two-way communications.

Even in parts of Europe where sophisticated, interactive digital totems have become ubiquitous, 
their capabilities are only just starting to be harnessed. They still have plenty of potential, in an increasingly interconnected world, to change the way businesses and other organizations communicate with locals 
and visitors.

It is not merely a matter of establishing two-way communications to generate feedback from passersby. Mobile phones could interact with totems for security purposes, for example, and with ‘emotional reading’ software now in development, digital signs could even be used to detect distressed individuals for safety purposes.

Before moving on to such advanced purposes, however, outdoor totems have had to contend with a number of disadvantages compared to more well-established indoor digital signage networks.

Heating and solar issues
For a long time, the biggest problem facing outdoor digital signage has been the need to withstand ambient environmental threats that can be destructive to electronic devices. Consumers can appreciate this need with regard to their own personal mobile phones; water, humidity, dust and snow can all have negative impacts on these devices and it can certainly be a struggle to read and use their screens in direct sunlight. The struggle is compounded for digital signage because outdoor deployments often must operate all day, every day, for years, making the chances of success much slimmer. A series of engineering challenges must be dealt with to ensure effectiveness and reliability.

The two biggest issues are connected by way of the sun: readability and thermal management. Not only does sunlight make readability difficult, but the associated heat is also a pressing threat, as black spots can appear on a liquid crystal display (LCD) screen when its surface temperature exceeds specified limits, leaving portions of the screen completely obscured. Constant overheating can also cause integrated electronic components to degrade extremely quickly, shortening their useful life. Moving toward the operational bounds of digital signage systems will generally cause reductions in brightness and response time; going beyond those bounds can result in permanent damage.

In fact, most problems and disappointments encountered in the past with outdoor digital signage systems have been related to inadequate thermal regulation technologies integrated with LCDs. Everything looks 
fine at first, but after the first few months, overheating has left the screen unreadable, turning the whole unit into expensive, useless street furniture.

A relatively small difference in inner temperature can mean the difference between a readable screen and an unusable device. It is thus crucial to maintain stable inner temperatures, both to ensure performance and to protect the initial investment.

Damaging heat, in this context, is primarily generated from three sources: solar radiation (particularly dangerous with low-horizon sunlight), ambient air temperature and the digital signage system’s own integrated panel and electronics. Unless highly rugged electronics are specified for the panel and components, these systems are not designed to operate effectively when their internal temperature exceeds 50 C (122 F). This may sound extremely high in Canada, but it is not; the inside of a car can easily reach such temperatures in the summer.

Indeed, someone sitting in a hot car in the summer will need to open the windows and turn on the air conditioning (AC). As it turns out, that is exactly what’s needed for outdoor digital signage systems, too.

A digital signage system’s integrated electronic components should be (a) hermetically sealed to prevent any water and dust from reaching them and (b) kept at stable inner temperatures to ensure their efficient operation. These needs suggest implementing an independent heating, ventilation and air conditioning (HVAC) system, as anything less will impede the whole unit’s performance and durability.

Readability issues
As mentioned, maintaining stable surface and interior temperatures will help integrated LCD panels function at their peak performance levels, providing optimal readability. People’s eyes notice visible light sources as luminance/brightness and perceive images as differences in shades, so to be seen clearly, LCD panels selected for outdoor digital signage systems need to be both high-brightness and high-contrast.

For the best results in direct sunlight, a screen should be able to operate continually at a minimum luminance of 1,500 nits in bright sunlight. That said, lower luminance levels—e.g. 700 nits—with high contrast levels may still delivery clear readability, if properly integrated into the unit design.

It is important to be careful. The technical specifications for LCD panels’ contrast levels can be slightly misleading, as they are measured for displays in a pitch-black room, rather than in a real-world outdoor environment where ambient light reflecting off the screen will reduce the perceived differences between the brightest and darkest pixels.

Direct exposure to solar radiation, with light reflecting directly from the screen, is especially problematic. Around noon on a sunny day, daytime illumination can reach 96,000 nits, even without taking into account other objects in the vicinity reflecting further light onto a screen.

With this in mind, a screen’s high-brightness and -contrast performance should be supported with a high-quality anti-reflective glass treatment. This will help ensure images remain comfortably viewable—and text readable—throughout the day.

Careful investments
With these factors and conditions in mind, it is often worthwhile to invest in rugged technologies from the start, so the digital signage will last longer in the field. Today, state-of-the-art systems are available with a three-year guarantee. And they should last even longer—some have operated in Europe now for more than five years, in climates comparable to Canada’s.

That is not to say no maintenance will be required during the deployment period of three or more years. Rather, a realistic initial budget should allot some funds for occasional maintenance and account for ‘emergency interventions.’ When a system is down, the immediate attention required can prove expensive if not covered by the guarantee.

Also, compared to indoor digital signage, outdoor systems demand more product research, as even when they integrate the same components, their real-world performance can vary greatly from one location to another. It is important to test demonstration models, checking their performance in direct sunlight, and vital to understand exactly how systems are warranted with respect to other ambient factors.

For that matter, it is all the more important compared with indoor installations to determine (a) if it will even be possible to install digital signage at the intended outdoor location and (b) if so, how much it will cost to do so. Regulations will vary and bureaucracy can delay installation and other processes for long periods.

When well-placed in a suitable environment, however, outdoor digital signage systems 
can prove highly successful in enhancing communications with locals and visitors and in improving sales and marketing campaigns, to the point where they may more than pay for themselves. Further, some cities’ tenants and clients value capabilities of outdoor digital signage for catching the attention of younger people, attracting new customers and presenting themselves as innovative and progressive, to the point where these factors comprise a viable sales proposition. With this in mind, it could be even more costly not to consider outdoor installations than to move ahead with them.

David Dumouchel is director of communication for Montreal-based Diopso, which provides indoor and outdoor digital signage systems and related software. For more information, visit www.diopso.com or contact the company via e-mail at info@diopso.com.

Source URL: https://www.signmedia.ca/digital-signage-taking-messaging-outdoors/

---