Types of Touch Screen Technologies
You use touchscreens daily. They're on our phones, in our automobiles, and in nearly every device we
use. That is why we created a guide to the most common types of touch screen technology available
today. UICO specializes in providing Projected Capacitive (PCAP) touchscreen solutions for harsh
environments. To assist you in making educated judgments, we've compiled a guide to the most
prevalent types of touch screens: PCAP touch screen (PCAP), Resistive touch screen, surface capacitive
touchscreen and the surface acoustic wave touchscreen.
PCAP Touch Screen (Projected Capacitive Touchscreen)
Technology: A PCAP touch screen consists of a glass or acrylic top cover lens with an active conductive grid layer of X and electrodes laminated to the back side of the cover lens. These electrodes emit an electromagnetic field that is disturbed when a finger touches the front surface of the cover lens.
Operation: When a conductive object, such as a finger or stylus, touches the screen, a PCAP touch screen disrupts the electrostatic field, allowing the screen to detect the touch.
PCAP Touch Screen Advantages:
Multi-Touch Support: PCAP screens enable multiple touches on the touch screen usually simultaneously, facilitating a true multi touch experience. Multi touch PCAP supports touch screen movements like intuitive gestures, pinch-and-zoom, swiping, multiple users on the same touch screen.
Durability: Known for robustness, PCAP touchscreens are resistant to scratches and contaminants due to the cover lens being an inert glass surface, typically chemically strengthened or hardened tempered glass. PCap also supports thicker glass substrates (1.1mm to 10mm cover lens glass is possible)
Resistive Touch Screen
Technology: A resistive touch screen is comprised of two layers separated by a small air gap. The top layer is typically a flexible conductive PET film, while the bottom layer is a rigid glass substrate with a conductive coating.
Operation: When pressure is applied to a resistive touch screen, the top layer makes contact with the bottom layer, electrode patterns around the perimeter of the top and bottom registering touch positions based on resistance or current draw.
Resistive Touch Screen Advantages:
Durability: Resistant to moisture and dust depending on the touch screen design and sealing gaskets applied. Semi suitable for challenging environments based on the top PET sheet durability. Works well with a stylus or gloved hand.
Surface Capacitive Touchscreen
Technology: Capacitive touchscreens use a glass substrate with a transparent conductive ITO layer applied to the front surface. Typically, a top surface hardened layer is applied to protect the conductive ITO surface from wear and scratches.
Operation: Touches occur when a human finger touches the front surface of the touch screen allowing the touch controller to measure small amounts of current with a surface capacitive touch screen. Touch is determined by the amount of current measured at each of the 4 corner measurements and controller algorithms designed to calculate the exact position on the touch screen. Surface capacitive requires a human finger touch on the front surface directly or a driven stylus tied to the same grounding as the touch controller to work.
Advantages of a Surface Capacitive Touch Screen: Surface Capacitive screens are highly
responsive, work well with fast drag and drawmovements, and can support gestures depending on the software interpretation of single finger movements on the touch screen.
Clarity: Excellent optical clarity due to the absence of additional layers.
Surface Acoustic Wave Touchscreen (SAW)
Technology: SAW touchscreens have transducers at the screen's corners that send and receive ultrasonic waves along the surface.
Operation: When a finger or stylus touches the screen, it absorbs some of the waves, altering the wave's amplitude and allowing the screen to pinpoint the touch location.
Advantages of SAW:
Durability: Highly durable and resistant to physical damage.
High Clarity: Offer excellent image clarity and brightness.
At UICO, we specialize in delivering rugged PCAP touchscreen solutions that excel in harsh environments. Contact us to discuss your project and explore how our PCAP touchscreens can meet your specific rugged computing needs. Understanding the various touchscreen technologies available for rugged PCs is essential when selecting the right solution for your specific application. Whether you prioritize multi-touch support, durability, or precision, each technology has its strengths and ideal use cases. Choose wisely to ensure your rugged PC meets the demands of your environment and users.