Capacitive and resistive are the two leading types of touchscreen technologies. Powering smartphones, tablets, computer monitors, smart appliances and human machine interfaces (HMIs), they both allow users to control the respective device using touch commands. And while there’s no signs of resistive or capacitive technology slowing down anytime soon, there are new touchscreen technologies emerging, including infrared (IR). IR touchscreen devices work in a similar manner by supporting touch commands. However, they are unique in the sense that they rely on IR light to perform this task.
There are actually two different types of IR touchscreen technology, each of which uses a different method to detect touch commands. In this post, we’re going to take a closer look at these technologies, revealing how they differ. Using this information, you can decide which type of IR touchscreen device is right for you.
IR Acrylic Projection
IR acrylic projection is a type of IR touchscreen technology that uses an acrylic layer as a projection screen. Around the perimeter of this acrylic layer is an array of light-emitting diodes (LEDs). When an IR acrylic projection device is turned on, these LEDs illuminate the acrylic layer. There are also cameras on the back of this acrylic layer that measure IR light. Upon touching the surface of an IR acrylic projection device, your finger will disturb some of the light produced by the LEDs. And the cameras will identify this distortion, using it to determine your point of contact. Acrylic projection has become a popular choice thanks to its highly accurate and responsive characteristics.
IR Optical Imaging
The other type of IR touchscreen technology is optical imaging. With optical imaging, IR backlights are installed on the opposite side of the screen. Touching the surface partially blocks this light from hitting the cameras, allowing the device to determine where exactly you touched. It’s similar to acrylic projection, being that both technologies feature a combination of lights and cameras (sensors). The difference, however, is that IR optical imaging uses cameras around the exterior edges of the device, whereas IR acrylic projection uses cameras around the inside perimeter of the device. IR optical imaging is an affordable, cost-effective solution for IR touchscreen applications.
To recap, the two types of IR touchscreen technology are acrylic projection and optical imaging. They both use light and cameras to detect touch commands, with IR optical imaging costing slightly less than its IR acrylic projection counterpart.