Not All Touch Displays Are Created Equal
What to look for in purchasing a large touch display or multitouch table. Touch technology, resolution, and build quality all make a difference.
Every day we receive questions about our touch displays, the technology they use, and how they stack up to our competitors. We’ve been developing large-scale multitouch tables and displays since 2008 and we’ve incorporated a lot of different types technologies as our product line has evolved. With so many differences in touch technologies, screen resolution, build quality, and durability it can be confusing to potential purchasers.
Our focus has always been on creating the highest-quality displays and touch tables for museums and others. We are committed to incorporating the latest and most responsive touch technology. All of our models are lockable, have push button operation, and are housed in aluminum chassis that we design and build here in the US. Our displays and touch tables tend to be more expensive than many of our competitors, but if you understand what goes into them, you’ll understand why.
So how do you evaluate which touch display or touch table is best? Here are the qualities that matter most.
There are huge differences in the fidelity and qualities of various touch technologies. Here we outline the two most common technologies that are used in large-scale displays: IR overlays and Projected Capacitive Touch.
IR overlay is the most common type of touch technology. This optical technology uses infrared light, as your finger breaks the beams of light, the system detects a touch point.
IR overlays work pretty well for touch walls and in environments where light can be controlled. They can be susceptible to light interference, particularly sunlight. The overlay requires a bezel around of the edge of the screen so the surface is not completely flat. For this reason, we no longer use IR overlays for any of our standard-sized flat multitouch tables (we still use it for our Drafting Table 65 and Presenter 65 and our Presenter 75 models). The bezel on IR systems can also make cleaning and maintenance a bit harder, as the bezel can collect grime.
The quality of IR overlays can vary significantly, as can the number of touch points that are supported. IR overlays are commonly used in inexpensive displays. IR overlays can be purchased to fit on existing screens, but these are not “hardened” solutions that perform well in public spaces. It is worth mentioning, that if a vendor is selling a touch screen and doesn’t mention which technology is used, it almost always an IR overlay.
Projected Capacitive Touch (PCT, also PCAP) is emerging as the clear choice for touch technology. It has been used in smart phones and tablets for years, but it has been difficult to scale it to work with larger screens. Projected Capacitive touch uses a thin layer of conductive material to form a grid. As voltage is applied an electrostatic field is then created across the grid. As users touch the screen (or another capacitive object touches the screen) the field is distorted. Hardware and software are then used to recognize touch points.
Since Projected Capacitive Touch is non-optical it is impervious to light interference. Unlike IR overlays it is also bezel-less. PCAP is the first choice for most people who understand touch technology well. However, like IR overlays there are differences in the available PCAP solutions. There are a few different types of PCAP including: metal mesh, ITO (indium tin oxide), and silver nano wire — all of these can work well — what’s important is the number of touch points and the fidelity and responsiveness of the particular touch panel. We have sought out those touch solutions that provide the best combination of these qualities. When comparing PCAP displays it is worth looking at specifications such as response time and the number of simultaneous touch points.
HD (high definition) and 4K UHD (ultra high definition) are two display resolutions that are available for large scale touch displays and touch tables. UHD displays have a resolution of 3840 x 2160 vs. 1920 x 1080 for an HD display. For smaller displays, 42” or 46” sizes, HD is generally fine for displaying most content. In fact, currently most content is developed for HD displays.
Once you start to hit 55” or above in size, the resolution begins to make more and more of a difference (the “pixel density” in these larger sizes spreads out the number of pixels causing degradation of the content). Recently we stopped offering HD resolution for our 55” and larger displays. Regardless of from whom you buy, we would recommend that unless your budget is very constrained that you “future proof” your investment by purchasing touch screens with UHD display capability.
While most people don’t think too much about the “case” the display comes in, it can make a big difference particularly for public spaces or even semi-public spaces such as schools or corporate settings. We started out working almost exclusively with museums, so we’ve concentrated on developing hardened solutions that are locked down for public spaces. Our cases are made out of aluminum with lockable access panels and we make them as thin and as durable as possible. Again, this does add cost, so the buyer needs to understand whether this level of quality and attention to detail is something worth paying for.
Most touch displays and even some touch tables from our competitors are not completely protected for public spaces. Many displays use cheap plastic from Asia, which is neither durable nor conductive. Aluminum has the advantage that it can help to reduce heating of the display inside.
The Complete Package?
Our 55” Presenter, Platform, Pro, and Drafting Tables all have 4K UHD displays, with the latest in 3M Projected Capacitive touch technology in a rugged, aluminum, turn key system. We are proud to say that we are currently the only company to offer a 55” 4K UHD display with 3M touch technology. Our products are designed, built, and supported here in the US, by an American-owned company. We take pride in what we do. If you’ve made it this far in this blog post, we hope you have a better understanding of what makes our products unique.
This article was originally published on the Ideum blog.