TOUCHSCREEN

• A touchscreen serves a dual purpose: it acts as an input receiver for computers (like tapping an app) and displays the output (such as launching the app). Apart from smartphones, touchscreens are now common in ATMs, household appliances (like TVs and AC panels), e-readers, billing systems, and electronic voting machines.
• According to historical records, the touchscreen's inception is credited to engineer E.A. Johnson at the Royal Radar Establishment in Malvern, U.K., in 1965. Johnson detailed his invention, a capacitive device detecting finger touch, in two papers published in 1965 and 1967. He envisioned its use beyond air traffic control systems.
• Another significant advancement was the development of the resistive touchscreen in 1970, attributed to G. Samuel Hurst at the University of Kentucky. These inventions spurred further innovation.
• For instance, Nimish Mehta at the University of Toronto pioneered a multitouch-capable touchscreen in 1982, while Myron Krueger, an American artist, explored capturing various hand gestures on a screen in 1983. Building on these, Bob Boie at Bell Labs created the first transparent multitouch interface in 1984.
• While touchscreens were adapted for non-expert use with computer terminals in the early 1970s, their widespread adoption began in 1993 with IBM and BellSouth's Simon, a portable email-capable device.
• Subsequent devices like Apple's Newton, the Palm Pilot PDA, and others popularized touchscreens. In the early 2000s, engineers introduced wall-sized touchscreens, enhanced computer capabilities for touch and gestures, multitouch-enabled touchpads, and overall touchscreen improvements.
• In consumer electronics, 2007 marked significant breakthroughs with the release of the LG Prada and the Apple iPhone, the pioneering phones featuring touchscreens

A touchscreen is a user interface that allows interaction with electronic devices by directly touching the display screen. It enables users to input commands or interact with digital content by physically touching the screen, eliminating the need for external input devices like a keyboard or a mouse.

There are several types of touchscreen technologies, including:

1. Resistive Touchscreens: These consist of multiple layers. When pressure is applied, the layers make contact, determining the touchpoint. They are durable but can be less sensitive to touch.

2. Capacitive Touchscreens: They use the electrical properties of the human body to detect touch. When a conductive object, like a finger, touches the screen, it disrupts the screen's electrostatic field, allowing the device to pinpoint the touch location.

3. Surface Acoustic Wave Touchscreens: Utilizing ultrasonic waves on the screen's surface, they detect touch by measuring the disturbances caused by touching the screen.

4. Infrared Touchscreens: These use infrared light to detect touch. When an object touches the screen, it interrupts the infrared light beams, enabling the device to identify the touch location.

Touchscreens are commonly found in smartphones, tablets, laptops, ATMs, interactive kiosks, information displays, and various other electronic devices. They offer intuitive and user-friendly interactions, facilitating a wide range of applications in both personal and commercial settings

4. How do touchscreens work?

• The two primary types of touchscreens are capacitive and resistive, although various other methods exist. Among these, capacitive touchscreens are utilized in smartphones and other portable devices designed for information access.
• A capacitive touchscreen comprises a surface embedded with a grid of capacitors.
• A capacitor, an electronic component, consists of two parallel plates with an air gap between them, each plate linked to the circuit. These plates store electrical charge.
• When a user's finger touches the surface, a small charge from a nearby capacitor moves through the circuit into the finger, altering the electric field at that spot. Sensors positioned along the screen's edges detect this alteration and transmit it to a signal processor, determining the point of contact. (This explains why some touchscreens may not respond to touches when the user is wearing gloves.)
• A more complex method, known as the projected capacitive approach, is employed in smartphones utilizing mutual capacitance architecture. In this method, two conducting layers contain strips of conductive material, with one set of strips running horizontally and the other vertically. When these strips intersect, they form capacitors, and changes in their capacitance help locate where the screen was touched. This technique enables the detection of multiple simultaneous touches.
• In contrast, resistive touchscreens use resistance. They consist of two conductive sheets separated by a small gap.
• When a finger touches one sheet, it presses it to touch the underlying sheet, allowing an electric current to pass through. Sensors detect this change using a grid of wires attached to one of the sheets and, with the aid of a processor, determine the touchpoint. Other touchscreen technologies rely on optical or acoustic wave inputs, among other methods.
• Between 2007 and 2013, capacitive touchscreens surpassed resistive touchscreens in the consumer electronics market.
• Resistive touchscreens are cost-effective to manufacture and consume less power. However, as per a review published in the journal Sensors in July 2021, capacitive touchscreens offer superior image clarity, sensitivity, and durability