There are several variants of touchscreens available on the market. Although they may appear visually similar, they are different solutions characterized not only by their operating principles but also by factors such as sensitivity, precision, resistance to damage, and light transmittance.
Touchscreens are a universal term used to refer to the combination of displays, touch sensors, and glass. In our offer, we consistently provide two types of touch sensors: capacitive touch panels (CTP) and resistive touch panels (RTP). Upon request, we can also provide solutions in other technologies such as IR (infrared).
Below, we will describe capacitive touch panels.
Principle of Operation of Capacitive Touch Panels
In capacitive touchscreens, the determination of touch location is based on detecting disturbances in an electrostatic field. Capacitive sensors are composed of electrodes made of indium tin oxide (ITO), which can be arranged in two configurations: either in the corners of the screen (known as “surface capacitive”) or distributed across the entire surface of the screen (known as “projected capacitive”). These electrodes are overlaid on a glass substrate. When we touch the screen with conductive objects such as fingers or a stylus, their conductivity causes a change in the electrostatic capacitance between the electrodes through capacitive coupling. This change is identified and processed into touch points by the controller.
Learn more about the “surface capacitive” and “projected capacitive” variants from our comprehensive guide on capacitive touch panels.
How to Choose the Right Capacitive Touch Panel from Our Offer
When selecting a touch panel, it’s important to consider several key parameters, such as:
- Requirements regarding the size and aspect ratio of the display;
- Glass thickness, which affects the durability of the touch panel;
- Type of built-in controller.
Calibration of the Capacitive Touch Panel
In addition to the basic parameters, it’s also important to take into account factors present in the device’s operating environment that may require the calibration of the capacitive touch panel (this is an additional service that can be provided in collaboration with the Unisystem team). In some projects, these enhancements may include:
- Water rejection mode, which ensures proper operation of the touch panel when water is present on the screen surface;
- Palm rejection mode, which ensures proper operation of the touch panel when larger objects, such as the entire palm, come into contact with the screen surface;
- Noise detection or frequency hopping functions, which dynamically adjust the module’s operation to the prevailing environmental conditions, particularly useful for handling frequent changes in interference levels and frequencies.
Touch Panel Finish – Glass Customization
Visually appealing devices are attention-grabbing. This drives manufacturers to create solutions that undergo various modifications, such as painting the glass edges.
Designers increasingly take advantage of glass customization options, including:
- Glass trimming;
- Cutting holes in the glass to accommodate necessary mechanical elements such as buttons, switches, or knobs;
- Glass painting.
Learn more about designing touch solutions from our touch panel customization guide.