How To Select The Right Touchscreen Panel

IR grid technology. Another type of mostly used touch panels are the IR touch panels (ITPs). IR technology consists of IR LEDs and light sensors that are placed on the perimeter of the bezel. LEDs transmit beams of light that run side by side to the assigned light sensor and create a light grid. If anything disrupts the light or reduces it, a touch point is registered by the controller.

Performance is sensitive to water, snow, rain and ambient light interference. The screen could malfunction due to build up of dust, oil or grease. Cost is relatively high as compared to other touch technologies.

SAW touchscreen. A SAW is a structure-borne sound wave that spreads across a surface in a planar manner, that is, in two dimensions. The receiving transducer locates the touch point and sends this data to the controller.

SAW touchscreens have excellent image clarity, so can display high-detail graphics. These can be activated by a finger, gloved hand or soft-tip stylus.

However, SAW panels are the most expensive of the three liquids, and any contact with something hard like a pen or finger nail can cause a false trigger. Solid contaminants on the screen can create non-touch areas, until removed.

Optical touchscreens. This is a relatively-modern development in touchscreen technology, which uses two line-scanning cameras located at the corners of the screen. IR backlights are placed in the camera’s field-of-view on the other side of the screen.

This technology is growing in popularity due to its scalability, versatility and affordability, especially for bigger units. It permits 100 per cent light transmission and requires only one calibration.

Near-field imaging touchscreens. This is one of the newest technologies and consists of two touchscreens. When the finger, glove or any other conductive stylus comes into contact with the sensor, electrostatic field is disturbed. It is an extremely-durable screen that is suited for use in industrial control systems and other harsh environments.