How a Smartphone Touch Screen Works

Smartphone Touch Screen

It was not so long ago that we had to tap on the tiny keypad of smartphones or use the micro-keyboard of different smartphones. It was in 2007 when the touchscreen was introduced, and everyone started swiping their fingers across the screens and pinching images and performing other functions with their bare fingers which were earlier not possible. Touchscreen now has become a part of our everyday experience, but have you ever wondered, how it works. Here’s how!

There are different touch technologies available which are distinctly different. Some deploy infrared light technology, and few others use sound waves or force sensors. Although there are different touch technologies available with their respective pros and cons, there are two technologies that are randomly adopted and used by the smartphone industry. They are resistive touchscreens and capacitive touchscreens. Below we discuss both and the underlying technology that is made to use in making our smartphones work as we swipe our fingers over them.

Resistive Touchscreens

Resistive touchscreens have glass panels that are covered with both resistive and conductive metallic layers beneath the surface. This technology is used in many smartphones and is typically used in ATMs and supermarket checkouts and other appliances for public use. The resistive and the conductive metallic layers beneath the glass surface are held apart by a spacer and electrical current runs through them when the screen is operational. With the user’s touch of the finger, the two layers make contact in that particular spot. The change in the electrical field is noted, and the device driver translates the touches and movements to the operating system of the phone.

Capacitive Touchscreens

These glass touchscreens are primarily used by the smartphones of premium brands which are covered by a transparent conductor layer which stores electrical charges. On the touch of the user which is also conductive the electrical field gets distorted at a particular point. This helps the device to find out the point at which the screen was touched which it relays to the device driver which in turn gets transmitted to the OS of the phone. Although this type of technology is used in many phones, one of the drawbacks of this technology is that it does not respond to the touch of electrically insulated materials. In case the fingers are covered by gloves or other electrically insulated material the technology won’t work.

The term capacitive touchscreen comes from the term capacitor which is an electrical device that stores electrical charge temporarily. Although capacitive screens are widely used in smartphones resistive screens are relatively cheaper, and you can even touch them with fingers and gloves. The disadvantage is that you can’t swipe it or use it with multi-touch gestures as they are designed to respond to pressure. Touchscreens with resistive technology have been around since the 1970s, but capacitive touchscreens are increasingly used in the smartphones that we use.