What is digital signage?

Digital signage means many things to different people but in essence it’s the ability to replace conventional printed signs and posters with big screens such as large TVs. A signage system should have an editor to allow you to create your own screen designs and messages.

Other types of more specialist systems exist such as huge outdoor billboard displays (normally using bright lamps or LEDs) but by and large LCD screens are the mainstay of modern signage systems.

Unlike conventional signs, digital signs can be instantly updated from your office, and with cloud based signage, anywhere with an Internet connection. This obviously has huge benefits in both time and cost.

What are the benefits of digital signage?

You might have a number of large posters you want to put up in an area that doesn’t have the space to accommodate them all.

A single large screen can display all your posters or messages full screen one after the other, or together in the space of a single screen.

In the past, putting a lot of large signage screens around your building was an expensive proposition, and the return on investment was probably difficult to justify for smaller organisations, especially as it can be difficult to tell if putting up a screen has made any difference, especially in a retail environment.

Like most things, prices for digital signage have tumbled so it’s no longer expensive.

Signage advertising systems

The type of digital signage that most people will encounter in their daily lives is used for advertising.

Lots of the big supermarket chains have a huge outdoor screen beside the entrance showing adverts. Not unlike poster campaigns, you can gain some indication of how effective they are by checking sales against the screen content.

Some screens have cameras in them that can provide footfall information or change the display content based on the age group or gender of the people in front of the screen.

With advertising systems, a screen outside or inside a large retail store for example might be owned by an advertising company that pay the retailer for allowing them to put the screen there.

The screen operator will source the advertising content so the retailer just takes income from the advertising company. This doesn’t just apply to retailers, anybody that owns some public accessible space can rent it out to signage operators.

Indoor signage screens

Indoor screens are a much easier proposition in comparison to outdoor screens and in most cases you can just use a large screen LCD TV.

Be aware that the domestic TV sets aren’t as bright as dedicated signage screens so won’t be any use if you put them in a sunny window or where the sun might shine on them. For those situations you will need a special high brightness screen.

Domestic TVs are not normally designed to be left on 24 hours a day and their internal ventilation may be compromised if you operate them in portrait mode as they are not normally designed to operate that way.

That said, they aren’t as expensive as a commercial panel which is why you see them in use all over the place. Modern TVs have very little electronics inside them and don’t generate anywhere near as much heat as they did ten years ago.

If you’re putting up screens somewhere that’s difficult to get to you would be better off installing a commercial panel that’s designed for 24/7 use. One person up a ladder isn’t going to be able to take down a 75″ screen without falling off a ladder or dropping it, so you want something that’s reliable in such locations.

Outdoor signage screens

Building an outdoor screen isn’t just a case of putting a large high brightness screen in a big metal box outside and hoping it works.

There are a number of safety, environmental and electrical requirements to satisfy. Typically you need to allow any heat to escape in the summer, the rain and moisture to be kept out and to prevent anybody getting electrocuted if they touch it.

Modern outdoor enclosures have air conditioning units and heaters built into them. If you get it all wrong the glass covering the screen will just steam up or the damp will cause the electronics to fail.

What are commercial signage screens?

These are normally designed for 24/7 operation and often don’t have TV tuners in them.

Commercial screens can also be operated in landscape or portrait modes without any potential heat buildup as they’re designed for running in both orientations. They are often brighter than normal TVs but not as bright as high brightness screens, unless that’s what you ordered!

They might also come with a built in software timer to switch the screens on or off at different times of the day.

Anybody that has tried to switch off a bank of the same type TVs at once with a remote control will tell you things go wrong and some will stay on. Once some are on and others are off it’s difficult to get them all on or all off again!

One other advantage they usually have is that the outer bezel is the same width on all sides and there is no makers name on the front that looks out of place if you mount it in portrait mode.

As a note, UK betting shops usually have banks of normal TVs that are switched on all day, simply because they are cheaper, lighter and offer more choice.

What about signage screen orientation?

Screens can be positioned in landscape orientation like your TV or positioned vertically in portrait mode.

There is no ‘best way’, and something like space might dictate which is best. However, to ensure the same media fits on all your screens it would be best to keep them all in the same orientation otherwise you will need to make two versions of everything.

A screen in portrait mode can be split into three sections, and each section will be more or less the same aspect ratio as a widescreen display.

Three screens next to each other in portrait mode are also more or less the same aspect ratio as a normal widescreen display, so they could be operated as three separate signage channels or one huge landscape channel.

Advertising screens are often positioned in portrait mode so if you are planning on displaying video on them you will either need to have it made especially for that orientation or to maintain the normal aspect ratio and display it on a third of the screen.

Which operating system do signage players use?

Signage players typically or historically run Microsoft Windows, but that’s now shifting to other platforms. These can be Linux, Android and Chrome.


Systems running Windows are easier for the end user to fix or administer as due to its widespread use people are familiar with it. Windows 10 home versions aren’t the best option as the Windows update can’t be switched off so you might find the screen out of action for a while when it decides to do a major update.

Ideally you would set the updates to happen during the night when nobody is looking at the screens.

On the professional version, update can be switched off.


Linux is fine for signage but it’s not without its problems.

The biggest issue is administering it as not that many people are familiar with it. Giving customers with a problem a list of complicated command line instructions to type in to try and fix it can make them glaze over fairly quickly and one wrongly entered command can break it requiring expert assistance.

The newest hardware often doesn’t have the required drivers to make it work efficiently so you might have to spend more on faster hardware to compensate.

That said, a ready configured Raspberry Pi 4 signage player from us shouldn’t give you any problems.


Android is a popular platform for signage as it’s used in devices like tablets with their built in screens to media boxes that plug into large TVs.

Android media players are often less than £40 and due to the large integration of the circuitry there is hardly anything in them to fail in comparison to a full blown PC. Android actually sits on top of the Linux kernel.

If your signage system is using an Android web browser this might appear to be running at a much lower resolution like 1280 x 800 even if your TV reports the device is outputting a resolution of 1920 x 1080 or higher. This is usually due to the way the  dpi for the screen is configured. It makes small fonts look big for viewing on a TV set from 6ft away. Sometimes there’s a menu setting to change it, if not we can normally alter it in a config file.

That said, signage tends to use fairly large fonts and is normally viewed from some distance away so unless you’re displaying complex tables of text high resolutions aren’t always necessary for typical use.

The one big downside to Android signage players is that unless the device is rooted it can’t be programmatically rebooted so you might need to restart the box manually if it stops.


Chrome OS is another contender but most of the Chrome boxes I’ve seen are no cheaper than a Windows 10 Net-Top class of PC that most people will know how to administer so it might be easier to stick with something you know.

How are signage screens updated?

Screens are normally updated over a network connection and each signage company will have their own method of updating the screens.

Depending on how the system is designed to operate display data can be sent to the screens as HTML pages or in a proprietary format. HTML5 with modern CSS supports lots of features including animation so using this format gives you more scope to use external applications such as JavaScript clocks. It also allows the system to easily keep up with modern display trends.

Media can be produced with built in page editors or are created elsewhere and saved as image files that can then be uploaded to the system. You could for example create display background images in PhotoShop and upload it to the system.

Multiple pages or images for display are then added into playlists or carousels so they are displayed one after the other.

A really simple way that some people use for signage is to just put a lot of images on a USB stick and plug that into a TV. This is OK if you only update the content once every six months as it’s not a very convenient way to put messages on screens. You may also get some onscreen graphics such as a Play / stop /pause from the TV media player that you don’t really want people to see.

Can I scan leaflets to display on the screens?

Yes, but bear in mind that anything printed by the print industry is made up of lots of tiny dots rather than continuous colour. Modern scanner application usually have settings for scanning printed items to remove any dot effects.

You might also need to crop the image afterwards to remove any scan borders or to isolate parts of the scan.

Once they are scanned you can upload them to the system and use them in the signage page editor.

Do LCD screens suffer screen burn?

A throwback to old CRT TVs is screen burn. If you left a static image on display on a CRT TV over a long period of time the screen would take on the image as the phosphors behind the screen became burnt.

Typically something like a screen that was only ever used to display airport flight information would show a shadow of flight times if you then showed something else on the screen. You could even see where the rows of characters were with it switched off if it was really bad.

Eventually the CRT (‘the tube’) would need to be replaced.

Plasma screen TVs also suffered the same problem. Some graphics cards had a Plasma TV mode that would keep shifting the picture around by a few pixels to minimise the problem.

Plasma TVs have been replaced by LCD TVs now so you’re unlikely to encounter one.

When LCD TVs first came out nobody thought they would suffer from screen burn, but they do.

A really burnt LCD screen is usually only fit for the rubbish bin, but ones that are not too badly gone can sometimes be repaired by showing changing patterns like an alternating black and white checkerboard or changing white noise patterns.

You might have to run the changing patterns for a week to recover the screen, so don’t expect instant results and don’t be too surprised if it doesn’t fix it, or the fix is only temporary.

It’s usually fairly easy to replace LCD panels, but in my experience the design of them changes slightly over time as their bezels get thinner so unless you get a panel with the exact same model number it won’t fit, or the mounting holes will be in a different place.

Some history of a very early digital signage system

Back in the past, way before PCs had any useful display capability and didn’t cost a fortune a number of companies took advantage of the teletext decoders in TV sets. One of the very first signage systems I was involved with in a previous job was for a since closed UK car plant.

Putting up notices in all the different sections of the plant took a long time as it covered such an enormous area. The solution was to use TVs with a custom made teletext decoder fitted into the set driven from a teletext generator they had on site. Messages were simply teletext pages, and different parts of the plant would have the TV display a different teletext page.

We’ve now almost gone full circle and are again starting to use the internal display smarts of domestic TV sets. This modern equivalent being the TVs built in web browser, although that often runs at a low 1280 x 800 resolution, even if the TV display is running at 1920 x 1080. The TV CPUs are usually incredible slow and underpowered, so for anything other than just showing a simple list such as flight times you are probably better off using a separate signage player for now.

It’s also much easier to replace a small signage player than the entire TV if something breaks down as man handling a very large TV is often a two person job.

Modern TVs support ‘apps’ that could provide the signage functionality although that eco system appears to be rather locked down and proprietary which makes it difficult to obtain data on how write and install them so it probably isn’t worth using unless you have a very large project.