Checklist for choosing a touchscreen
Considering the following factors and comparing them with the advantages and disadvantages of the key technologies, one will have a better understanding of what technology to choose: Size. Decide the size required by your application. Capabilities. Evaluate the type of functionality needed. Input method. Would it be a finger, stylus or glove? Number of points. Decide whether you want a surface with single-touch, dual-touch or multi-touch with X number of touch points. Environment. Ascertain the conditions that the surface will be subjected to. Durability. Know the expected life cycle of the device. Complexity. Evaluate whether the need is for a standard product or custom designed one. Regulatory restrictions. Are there any industry regulations that a designer needs to consider? Availability. Ascertain availability of replacement components should a component fail. Cost. Work out the budget for adding touch to the product design. For more, refer to the white paper ‘Choosing the Right Touch Technology,’ which serves as a great reference to understanding the strengths and limitations of each technology.
—Jamie D. Sewell, public relations & communications manager, Touch International greasy fingers, capacitive or IR type of touch technology is a better option, especially if the screen size is large.”
You should also know the application area of your device. Some people may want better optical clarity, some may want a robust screen, while some may want a low-cost screen. So there is no such thing as the best technology. The selection mainly depends on the use.
“Like, for large-format displays multi-touch capacitive has not evolved much, but on small format multi-touch can be seen on most touchscreen phones. So the use of a specific touchscreeen technology is really where its application is,” adds Taparia.
“One of the reasons for so many touch technologies is that there is no perfect solution,” says Sewell. She enumerates a few challenges that design engineers might face while working on some of these options: “Projected-capacitive technology can be difficult to integrate, so it is important to have an experienced team available during the integration process. This technology can be sensitive to noise and electromagnetic interference (EMI) and can also emit EMI. It is important to be aware of this when designing your product. You may need to include an EMI filter, mesh or gasket into the touchscreen depending on the application.”
Resistive touchscreens face the problems of low optics and a shorter lifespan. IR and optical systems have issues with occlusion and sunlight interference. It is therefore important to think about the environment in which the touchscreen will be used, to choose the right technology for the application.
Tapadia observes, “In any touchscreen solution the critical aspect to work on is the combination of experience that’s delivered via the touch interface. If you have a touchscreen that supports 40 touch points, an application that exploits these touch points is needed. However, what has been happening traditionally