Understanding Touch Technologies

We at Molden Media have gathered quite some experience with touch technologies over the years, and we would like to share them with you. Although most of us feel very well adapted to touch technologies, using our phones, tablets and touch screens on a daily basis, we do sometimes encounter very common misunderstandings when it comes to our installations. This article is an attempt to give you a heads up and make your experience with our installation as comfortable as possible.

mbc_touchscreen_screenshot_02

In terms of hardware, we have tried and tested almost all technologies on the market, and we are happy to work with most of them. However, we usually use a combination of HD screen and our custom infrared touch frames. The advantage of this setup is that our customers can hold on to the screens which they have previously purchased, not having to invest a large amount of money into new hardware, while we turn these screens into multi-touch devices through a simple and quick installation of our frames.

With every technology, specific details need to be taken into account by the operator. We have gathered a few to help with the most common problems that occur in using our multi-touch frames.

 

Installation

We will create a touch frame that is especially fit to match the dimensions of your screen. In case we are not around to do the installation ourselves, here are a few things you should keep in mind.

The touch frame requires an even surface for installation on a screen. It oftentimes helps to remove the manufacturer logo from the screen. These are usually glued on, so a blow dryer and a screw driver should do the trick.

removing-logo

The touch frame is an individual device and requires power and communication with your workstation. Always connect the work station, the display and the multi-touch frame to the same power outlet to avoid problems caused by voltage fluctuations. The frame will be connected to the workstation via USB. We highly recommend that you do not use USB extenders, since infrared multi-touch systems are highly sensitive measuring technologies that need absolutely stable communication. It is best to place a separate gateway PC right next to the installation. If this is not possible in your studio environment, we can recommend USB extenders that have proven to work. Please contact us for more information.

Before you move the screen and multi-touch frame, please make sure to power down the entire system, including the applications on your workstation that communicate with the frame. Carefully disconnect the power and USB cable from the frame and only then move the screen. Do not put pressure on the frame when pushing the screen along, since it might get deformed, which can result in faulty touch information or malfunction.

 

Creating Content

Our multi-touch frames use embedded infrared diodes that throw a grid across the entire screen. The diodes have a distance of about 5.6 millimeters, which results in a few design parameters that need to be taken into account. Touchable objects should never be smaller than 7 by 7 millimeters and never too close together. Please keep in mind that when you downscale content to run on a smaller screen and multi-touch frame, the distance between the diodes remains the same. Touchable objects might be too small for recognition at a lower resolution. If this is the case, you will need to adjust your content.

The infrared grid has a certain distance to the surface of the screen. This is necessary not only because of the way the infrared frames are manufactured, but also because we need to assure that the infrared barriers are never broken by the screen itself. This sometimes results in problems for the operator, especially when he triggers touch commands at an angle.

secondary-touches

 

If an operator uses his index finger to touch a button or move an object, it sometimes happens that he involuntarily triggers secondary touches with the knuckle of his pinky finger or the cuff of his shirt. Depending on the content, this can result in the sudden scaling of an image or pushing the wrong button. Please note that this problem can be easily solved by using the Group configuration in M2Touch Gateway, which will group a cluster of touch inputs into a singular touch command, thereby avoiding the effects of involuntary secondary touches.

Another problem is the so-called parallax effect, also caused by operating the screen at an angle. While the fingertip might break the barrier right above the correct spot, when moving the finger in or out, the point where the infrared barrier is broken will move along the finger and thus change position. Please see the drawing below for better understanding of the parallax effect.

parallax-effect

 

The problems caused by the parallax effect can be easily avoided through smart design choices. The size of and distance between touchable elements is key here. Very small objects crammed into a small space will increase the risk of false inputs. If you instead give touch buttons a reasonable size and arrange them well in your project, the parallax effect can be easily eliminated. In addition, the installation will be much easier to operate.

 

Training

Every multi-touch installation is only as good as the person operating it. This is especially true for live broadcasts, where an error or false reaction by the installation cannot be taken back. Therefore, we have found it crucial to bring the potential operator into the development process as early as possible. Not only will this lead to them getting well acquainted with the technology at an early stage, but they will also let you know how to set up the installation in order for them to feel comfortable with it.

Once the design is finished, take some time for an in-depth training with the operator. Show them every sub-menu, have them click on every button. It’s like learning to drive a car: They need to know their way around the installation by heart to guarantee a fluent and sophisticated show.

mbc_touchscreen_screenshot_01

If you keep these few details in mind, you can avoid the most common mistakes made when installing and operating multitouch frames. Naturally, we are happy to help if any issues arise, so please do not hesitate to contact us with questions and comments.

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