Touchscreen technology explained – Everything you need to know!

How does a touchscreen work?

As you know, unlike pressing the buttons, the touchscreen interface uses the fingertips as input. The touch inputs are identified or detected using the human body’s electrical conductive nature of our fingertips. In this manner, it registers the device input.

A touchscreen consists of three components – A touch sensor, a controller, and software. Let’s see what these components are and how does it work. Before that, take a look at some quick facts about touchscreen technology.

Quick facts:

• About 90% of touchscreens are Projected Capacitive Touchscreens (PCAP)*
• The average life span of a touchscreen is about three years.
• Almost all touchscreens feature an LCD.

*You will see different technologies in the later sections.

Touchscreen components explained!

1. Touch sensor or touch panel: A touch sensor consists of a touch-sensitive surface and detects changes in electrical properties like current, voltage, capacitance, and resistance.
2. Controller: The hardware component that converts the electric changes detected on the sensor to signals. The controller interprets touch gestures like sliding, zooming, and lock patterns.
3. Software: Upon receiving signals, the software processes the signals and completes the function. In this manner, a touchscreen detects the touch instruction.

“Only 1% to 3% of users perform two-thumb tapping when using a touchscreen.”

Note: Apart from fingertip sensing, the stylus is a pen-shaped instrument used to operate a touchscreen. The hardware picks up the signal once the tip touches the screen surface, and the user taps the switch on the stylus, which helps to draw and make selections.

Technologies

Many types of touchscreen variants are available in the market. The decision-makers or engineers choose the right technology based on the application and industry. Let’s see some of the technologies available for you.

• Resistive
• Surface acoustic wave
• Capacitive
• Surface Capacitive
• Projected Capacitive
• Mutual Capacitive
• Self Capacitive
• Self Capacitive
• Infrared Grid

The most popular technologies used widely are Resistive and Projected Capacitive Touchscreens (PCAP).

Let’s see brief details about these two popular touchscreen variants.

PCAP touchscreen

PCAP touchscreen consists of a glass sheet embedded with transparent electrode films and an IC chip that produces a 3D electrostatic field.

When a user touches the screen, the ratios of electrical currents change immediately, which helps the device to detect the touchpoints. For durability, the top is well covered up and protected. This variant is perfect for users with improved visibility and aesthetics. Also, using optical bonding instead of air bonding makes the screen stronger and anti-reflective.

Resistive touchscreen:

Resistive touchscreens consist of an ITO conductive coating & space dots sandwiched between two conductive layers and a glass or acrylic backing panel adjoined with the bottom layer.

The touchpoint is established on a PET film above the top circuit layer. When a user touches the screen, the layers converge to form an electric flow, causing a voltage change. This change detects the touchpoint, converts it into X & Y coordinates, and sends it to the controller.

Ergonomics:

Apart from device functionality, consider how the device appears to a user. The ergonomics determine the user response and interaction with the device.

The engineers are required to follow proper guidelines while designing the device with a touchscreen interface. For quick interaction, special gesture functions are used for touchscreen applications like single or double tapping and swiping for the best user experience.

Also, the inclusion of haptic technology – creating an experience by enabling vibration on touch commands is yet another feature to consider. While providing the touch features, one has to consider the trace it may leave on the device. For example, including fingerprint sensors for device security will leave touch marks on the display. Adding an optical coating will reduce the visible effects of fingerprints.

The application setting may also vary, and the engineer has to design a compatible with the settings. A perfect scenario is the glove touch compatibility of an application used in factory settings. If the touch sensitivity is incompatible with gloves, then the application won’t recognize the input. That’s why ergonomics is a key factor to consider.

Back to the past – Important milestones in the early history of touchscreens

To this day, the invention timeline has grown significantly, one after another.

What is ahead in the race – The future!

The scope for touchscreens in the future is vast. At present, we use devices with foldable screens that bend without breaking. The flexibility these devices offer is high. Also, the durability, which is on average three years, is increasing – one of the advantages we will witness soon. An ROI option!

Improvements in functionality, sensitivity, and durability are another future goal. The industries using touchscreen technology are also growing. With interactive techniques, ergonomics will improve, hence more user satisfaction.

Touchscreen manufacturers and suppliers are staying up to date in designing & researching the scope of hardware improvements. A lot more to come our way; for now, let’s focus on the present and wait to see what will roll out in the coming years.