All touchscreens have an integrated display. Whether it’s a smartphone, tablet or any other touchscreen device, it will feature a built-in display. You can touch the display to control the touchscreen. But not all touchscreens feature the same type of display. There are many several different types of displays used in touchscreens, some of the most common of which are listed below.
Liquid-crystal display (LCD) is a common display technology for touchscreens. It involves the use of liquid pixels, which are isolated in a layer. Behind this pixel layer is backlighting. Most LCDs use light-emitting diodes (LEDs) for their backlighting. Displayed labeled as “LED,” in fact, are typically LED-backlit LCDs. Regardless, many touchscreens use an LCD display.
Some touchscreens feature an in-plane switching (IPS) display. IPS is a variant of LCD. It involves the alignment of the liquid pixels so that they are parallel to the glass top layer. IPS displays apply an electrical current to electrodes on the glass top layer. This electrical current allows the liquid pixels to be switched, thereby changing their orientation.
Keep in mind that there’s also Super-IPS. Super-IPS is essentially an upgraded version of IPS. It’s not as common as its standard IPS counterpart, but some touchscreens feature a Super-IPS display.
Another LCD variant that’s commonly used in touchscreens is thin-film transistor (TFT). As its name suggests, TFT involves the use of thin-film transistors. It’s still considered an LCD technology that, like other LCD technologies, leverages liquid pixels and a backlighting solution. The difference is that TFT displays feature thin-film transistors. When compared to traditional LCDs, TFT displays typically offer faster refresh times and higher contrast ratios.
Some touchscreens feature a twisted nematic (TN) display. Like IPS and TFT, TN is a variant of LCD. TN displays have a layer of liquid pixels that are able to twist — as well as untwist — in response to an electrical current. This twisting action changes the polarization of the liquid pixels.
In recent years, organic light-emitting diode (OLED) has become an increasingly common display technology for touchscreens. OLED displays aren’t the same as LCDs. OLED is a relatively new display technology that involves the use of electroluminescent pixels. Electroluminescence means the pixels will emit light when exposed to an electrical current. During use, an electrical current will flow through the pixels in an OLED, thus activating the pixels.