If you have already purchased your screens, then you’re well on your way to setting up your digital signage network. If not, here’s a quick guide to choosing the right TV display for your digital signage.
Top factors to consider:
Types of TV Displays
Expected Display Lifespans
Screen Size and Viewing Distance
Display Resolutions and Pixel Density
Bezels and Video Walls
Price and Warranty
The Magic Behind the Screen
LCD vs LED vs OLED vs Plasma
Ever wonder about what goes on behind the pixels? TV displays today use various technologies to deliver an image. The most popular screen technologies today are:
LCD (liquid crystal display)
LED (light-emitting diode)
OLED (organic light-emitting diode)
LCD is the most common screen technology due to its low cost and high-quality image. Though the technology is old, their lower price point makes them the dominant market leader.
LEDs have a vibrant, brighter image compared most LCDs since their light comes directly from each pixel. Their higher price point has made them the second choice to LCDs.
The new kid on the block is OLED (organic light-emitting diode). They allow for sharp contrast and far deeper blacks than any other display type.
Plasma screens are no longer widely produced due to their tendency for image “burn-in”.
The Life of A Pixel
How Many Hours Will Your Screen Last?
If you’re spending big bucks on a TV display, then you should care about its life expectancy. These factors are usually determined by the quality and build-grade of the components of the TV. TV displays fall into one of two categories: consumer and commercial.
Consumer displays are meant for personal use. These are the TVs you’d buy for your living room and are built to display media like movies and video games. They often come with a large number of software features. They are not designed for rugged environments, and their lifespan is less than that of commercial displays.
Commercial displays are built to be kept on 24/7. They can be carefully colour-calibrated, and can easily integrate with third-party control devices. They often have more limited input options and may not always have built-in audio. However, they are an excellent choice for digital signage due to their purpose-built design. They’re also designed to be visible in both outdoor and indoor settings.
Commercial-grade screens excel in 24/7 usage environments such as public areas and transit hubs. Elements such as high humidity, volatile weather, and exposure to sunlight can damage outdoor displays. However, commercial displays are built to resist these factors. Commercial backlights can last up to 5x longer than those on consumer-grade screens. They also include security features that deter infrared tampering. That being said, commercial displays can 2-3x cost many times the price of consumer-grade televisions.
Like any light source, backlights will dim over time. Typical commercial LCDs can be expected to last around 100,000 hours. The light from an OLED screen comes from organic material that also decays over time. While earlier models were less reliable, new OLEDs have comparable 100,000-hour life expectancies. One thing to remember is that the brighter the image, the more power it will use, and the quicker it may burn out.
What You Need to Know About Screen Size and Viewing Distance
Screen size is important - but bigger is not always better. There are a variety of use cases that necessitate a variety of screen sizes. Smaller screens are great for kiosks, which is a popular use case for digital signage. Displays that are 50 inches or larger are the best screens for wall-mounting and reaching more than one or two people at a time.
TV Sizes and Viewing Distances: At larger sizes, LCDs tend to have a less reliable viewing angle. When considering LCDs, use the 4/6/8 principle for viewing distance.
The minimum distance a person needs to be from the screen to understand information is:
4x the screen height for detailed information.
6x the screen height for general information.
8x the screen height for at-a-glance information.
LEDs start to lose brightness at about 60° and have a maximum viewing angle generally of about 150°. Because of their intense brightness, this means they are the ideal choice for outdoor displays. Their minimum viewing distance in metres is measured by multiplying the pixel pitch by 1000. Pixel pitch is an industry standard of measuring pixel density in millimetres.
OLED pixels generate their own colour and light, so the viewing distance and angle are much improved. They will, therefore, retain their colour accuracy at extreme angles.
Talking ‘Bout My Resolution
Display Resolutions and Pixel Density
Resolution is a measure of the horizontal pixels by the vertical pixels. No matter what your screen size, you will want your resolution to be at least 1080p. The higher the resolution you choose, the more readable your displays will be.
The other factor in screen clarity is pixel density, or pixels per inch (ppi). Pixel density measures how many pixels are present in a single square inch area of the screen. The higher your ppi, the clearer your image will look when a viewer is close up. Higher ppi will diminish the “screen-door effect” that can occur when the resolution is too low.
4K resolution can allow for massive information clarity on a large screen. To run 4K, you will need to have a media player capable of outputting 4K in real-time. You will also need the necessary internet bandwidth to transmit 4K content reliably. 1080p is still acceptable for most display types. If you are planning to deploy screens larger than 65 inches, 4K is recommended. See our article on media devices to learn more.
Shine Bright Like a Backlight
How to Measure the Brightness of Your TV Screen
Measurement: The modern standard to measure display brightness is known as the nit (nt), or “candela per square metre” (cd/m2).
A candela is a measure of luminous intensity equivalent to the light of a single candle. It is a useful measurement of light emitted per unit area. Most HD LCDs have a nit level of between 450nt and 1,500nt. LED ranges from around 1,800nt to 6,500nt for outdoor displays.
OLEDs on the other hand generally have dimmer screens, typically producing around 800nt at their brightest. However, sections of the display that are black produce no light. This gives them unbeatable contrast compared to LCD.
Putting Your Best Bezel Forward
How Thin Should You Go?
A current trend in display design is to create smaller and smaller bezels. Bezels are the physical borders around the display that often house sidelights and hold the screen in place.
Why They’re Important: A thinner bezel means that your content can more easily stand on its own. The effect is most important when it comes to video walls. These require the viewer to look at a mosaic of screens and see just one large display. The smaller the bezel, the less the separation of screens is noticeable. Currently, the thinnest bezels available are around 1mm.
Caveats: When not using a video wall, bezels aren’t always a thing to be avoided. Screen bezels provide a visual buffer for your content against the environment around your display. This can help draw attention to your displays. In a busy environment, a larger bezel can make your display stand out more than it would on its own.
Budget for Less
Price and Warranty
Whether to get a warranty essentially depends on how you’re using your displays. Modern screens are very reliable. If your screens are indoor and not being touched often, you can expect nearly a decade of life out of them. Outdoor displays and kiosks may see enough use to make a warranty worth considering.
For digital signage, you do not need displays that include any consumer features like smart TV software. Be sure to avoid these as they can sometimes double the cost of a screen. While most commercial-grade televisions will not have these features, different brands vary in their feature-offerings.
Checklist: Before You Buy Your TV Screen
Second only to your content, your displays are the most essential part of your digital signage ecosystem. While your audience might not know the difference between an LCD and an LED, they will notice which one looks best.
Your audience is key to deciding which display type is right for you. You need to ask yourself:
- How long will they be looking at the screen?
- How far away will they be?
- Where will the screen be?
- How many people will view it at once?
- What kind of content is being displayed?
- Does the display need to be on 24/7?
Put yourself in the shoes of your ideal viewer and determine how they would interact with your display.
Determining what you want to accomplish with TelemetryTV will help significantly in making a more informed decision. If you would like to get started with a free trial of TelemetryTV you can sign up here.