LED vs LCD: What’s the Best Video Wall Solution?

As digital signage technology continues to expand, digital displays are exponentially increasing in size. At 25,000 square feet, the largest video wall in the world has been recently revealed in NYC's Times Square. It is said to provide advertisers with more than two million impressions weekly and spans an entire city block.

So, things are getting big...really big. Video walls aren't just made for a giant billboard in New York, they can also be used in a variety of places where disseminating information is important and advertising is possible. This can include:

• Auditoriums
• Atriums
• Broadcasts on-air
• Concerts and events
• Museums
• Retail
• Universities
• Corporations
• Hospitals
• Casinos
• Hotels

Fortunately, there are a full range of digital signage technologies you can leverage for a video wall solution that works best for your business. Some of the key considerations before integrating a video wall solution should be:

• Ease of implementation
• Image quality
• Location (indoor vs. outdoor)
• Design flexibility
• Physical footprint
• Ease of maintenance and cost of repairs
• Viewing distance

One additional detail you need to consider is the type of digital signage hardware you will be using. Higher-resolution LED is quickly catching up to LCD in popularity due to a decrease in the cost of manufacturing.

The two best options for a video wall are direct view (DV) LED displays and ultra-narrow bezel LCDs. Before deciding on which works best for your video wall, you should understand the technologies and costs associated with each.

What is a Direct View LED Display?

A wall of videos isn't an easy thing to accomplish and it requires smaller units working together to create a bigger picture. Direct view LED displays are comprised of several smaller LED screens mounted on a flat panel. LED stands for "light-emitting diode" and unlike LCD screens, the LEDs in DV displays produce light themselves. Each LED acts as a tiny bulb that emits color when electrically engaged. Rather than backlighting the images, the LEDs are actually producing them.

DV LED displays originally started out as monochrome and were often used in outdoor digital signage solutions. When RGB color LEDs hit the market in the late 90s, everything changed. DV LED is now the current leader in technology for digital signage and is advancing at a rate that puts it in direct competition with the pixel density of LCD video walls.

Pixel Construction

A modern LED used in video walls is coated with a black resin epoxy. Shades are inserted between the lights to eliminate reflectance and to achieve true black. This greatly improves pixel density and makes DV LED displays as high of a quality as any LCD on the market.

When installing an LED video wall, it is important to keep in mind the average viewing distance. Since most LED panels will not scale, the number of pixels is your resolution. The closer people are, the finer the pixel pitch needed. Typically, one surface mount device (SMD) LED is equal to 1 pixel in a video wall (and on that lies the RGB die). The pixel density is usually calculated by the pitch, which equates to the distance (in mm) between each SMD LED.

Advantages to DV LED Digital Signage

As LEDs become a more popular choice for video walls, the advantages to installing one continue to grow. The following are some of the benefits to choosing this type of hardware for your digital signage display:

• Seamless: LED panels have no bezels (seams) and can be tiled together
• Best refresh rates of any digital screen
• Long life ≥ 50,000 hours
• Achieves true black with epoxy coated LEDs
• Wide color gamut ≥ 95% NTSC and accuracy the best on the market
• Unmatched uniformity
• High brightness ≥ 800 nits
• Energy efficient
• Best viewing angles (widest too)
• Any size or shape, not only 16:9
• For handling ambient lighting, LED, vs LCD, does better, depending on overall brightness
• Depth varies, rear access common
• Better for outdoors

LED is an incredibly efficient application for high-impact visuals, but it's not the only one. LCD screens are also used in large video displays and, depending on the circumstance, they may be the better option.

Please note, when you are using the finer dot pitches of DV LED panels, they are very susceptible to damage along the edges during installation. If damaged, they typically require onsite repair by a service technician.

What is an Ultra Narrow Bezel LCD?

When it comes to a video wall solution, LCDs have been the popular option for years, and an ultra-narrow bezel LCD is one of the best suited for the job. LCD stands for "liquid crystal display" and chances are, you use this technology every day with your smartphone.

LCD panels in a video display are composed of a layer of liquid crystal that is sandwiched between two polarized pieces of glass. When electricity is applied, the liquid shifts to create an image. Since the crystals in this liquid do not produce their own light, a backlight is created to illuminate the display. LEDs are the most common means of backlighting LCDs, and the technologies are often advertised as a package deal, i.e. "LED-LCD."

Although LCD video walls are tiled like LEDs, there are spaces in-between the displays known as "bezels." The ultra-narrow bezel design is the most ideal for video walls because it creates the smallest seams. In fact, with the liquid technology and a narrow bezel, video walls can display a highly uniform brightness.

Pixel Construction

Each pixel in an LCD consists of a molecular layer aligned between transparent electrodes and polarizing filters. Pixelation is determined by an electric field and the placement of light. Other features:

• Single multi-layered LCD module
• 2M cells in module
• Pixel structure less visible
• Dense pixelation (compared to LED)

Advantages to Ultra Narrow Bezel LCD Digital Signage

There is a reason why LCD technology has always been the prime choice for video walls. The following are some of the advantages to choosing this hardware for your digital signage installation:

• Brilliant and fluid colors
• Higher resolution
• Energy efficient - reduce power consumption up to 50%
• Most affordable option on the market
• Easy to size and install
• High uniform brightness
• Slim installation depths
• Better for indoors
• Hardware is simple and easy to maintain
• Brightness ≥ 500 - 700 cd/m2
• Ultra-narrow and takes up little space

Please note, with the release of new sub-2 mm bezel gap displays, they have now become very fragile during installation. Due to the small piece of sheet metal holding the glass in place, any force applied along the edges can shatter the display, so extra care must be taken during installation.

Image quality, energy efficiency, size and location are just a few factors that will help you to determine the appropriate digital signage display. Whichever side of the LED vs LCD debate you're on, if you are choosing between an ultra-narrow bezel LCD or a DV LED for your video wall, you're already going in the right direction. Nothing captivates an audience quite like an entire wall of continual motion and vivid color.

Quick Things to Remember:

• Color uniformity is affected by light. Indoor use causes various light levels
• DV LED video walls should be calibrated for color uniformity for indoor use
• Beware of optimal viewing distances. LED-only vendors can understate them
• Brightness is the key concern for outdoor environments
• For indoor environments, the key concern is image quality and contrast
• Comfortable viewing distance equals half of retina distance
• Content, application, perception and budget are final determinants of hardware choice