As cost of hardware prices decreased, interactive video walls start becoming very popular in digital signage. To understand video wall technologies, we need to first compare the two main technologies, LED (Light Emitting Diode), and LCD (Liquid Crystal Displays).
Until a few years ago LED technology was mostly used in outdoor displays, where it was required to “fight against sunlight” and be seen by observers far away of it. This selection was natural as LED displays are more brighter than LCD with standard backlight. Examples of video walls can be seen here.
In the last couple of years, LED manufacturers start producing very high resolution with a dot pitch (or pixel pitch) of less than 1mm, making it also a great option for displays where observers are close to the display.
The first big question is who needs that. 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:
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:
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.
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. 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.
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.
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:
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.
When it comes to a video wall technologies, 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.
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:
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:
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. Whether you choose an ultra-narrow bezel LCD or a DV LED for your video wall, you’re going in the right direction. Nothing captivates an audience quite like an entire wall of continual motion and vivid color.
Displays are significantly growing in size and resolution with each year, and many companies are starting to use more advanced video wall solutions. For companies interested in jumping into the world of video walls, the biggest question they have to address is whether to use LCD or direct view LED displays.
There are a variety of tools one can use to craft a video wall. “There is a full range of technologies that can be leveraged to create a video wall – tiled or discrete LCD flat panels, rear-projection cubes, LED tiles projectors,” Andy Clipsham, senior product manager of global market solutions at Christie, said in an article. “Key considerations when selecting the best technology for a given installation include: design flexibility, physical footprint, ease of installation, image quality, ambient light tolerance, reliability, ease of maintenance and cost.”
Before companies decide on LCD or LED, they need to examine the hardware, software, cost and scenario.
Hardware for LCD displays is significantly simpler than for LED displays, according to Brian McClimans, vice president of sales, Americas and APAC, Peerless-AV. Customers typically only need to decide how large they want their image to be. From there, they can just add on additional LCD displays as needed to create the video wall. Direct view LED, on the other hand, requires a bit more thought.
“First, you need to decide at what resolution you need the image. As most LED panels will not scale, the number of pixels is the resolution,” McClimans said in an email interview. “With the advent of narrow pitched LED cabinets, form factors do not need to be as large as they once were. Once resolution is determined, the size of the deployment can then be spoken to.”
You also need to keep in mind the average distance most customers will be viewing the display from. If customers will be up close, you will need a finer pixel pitch.
For LCD displays, typically integrators just need to select a media player. They can select one that has the right amount of outputs for a video wall. They can also plug one into a video wall processor, or plug it into a wall of displays that daisy chain content.
LED software is similar but with one key difference. All cabinets have to plug directly from the video encoder or player, or all cabinets have to be daisy chained together.
“As most of these cabinets will be connecting via a traditional data cable (i.e., cat5e/cat6), there is often, but not always, additional information available on the cabinets that are in a deployment,” McClimans said.
Cost is probably the biggest barrier to direct view LED.
“While the prices for Direct View LED displays are projected to decrease, they are still quite a bit more expensive than LCDs. Your total cost will be impacted by the variables of the project, however, LED is the pricier option, for now,” McClimans said.
But cost alone can’t be the determining factor. You also need to examine the specific scenario.
You should consider a variety of factors such as viewing distance, environment, mounting hardware and content. McClimans argues that LCD displays are good for short viewing distances, for example, since they can display clear images, text and videos. However, the bezels of an LCD video wall are more visible than an LED display.
LED displays also might be better for outdoor solutions since they can handle ambient lighting better than LCD displays.
“There is no definitive right or wrong choice between LCD and LED displays for a direct viewing video wall, rather there are key variables to keep in mind when making your decision,” McClimans said.