The First Touchscreen Invented
A touch screen is an electronic visual device that permits users to control electronic devices (like phones, GPS, computers, tablets etc.) with just a simple touch of a finger or stylus. in general sensors have an electrical current running through them and touching the screen causes a voltage change. The voltage change signals the location of the touching.
The real inventor of touchscreens was E.A. Johnson, he published a short article in 1965 , and then in 1967 a more detailed article that came with diagrams and some photographs .
E.A. Johnson invented the first capacitive touchscreen but was never manufactured for consumers.
The first resistive touchscreen was invented by Samuel G Hurst in 1981 and produced in 1982 .
Systems are built based on different types of sensors: resistive (most common), surface acoustic wave, and capacitive (most smart phones).
What means capacitive and resistive ?
Capacitive Touch Screens
Capacitive touch screens use a layer of capacitive material to hold an electrical charge . When a user touches the screen with a finger, the electrical charge changes, and sensors at the edge of the screen detect this change and identify the spot touched. Capacitive screens proved to be a simple design, but any scratches or damage to the screen could substantially reduce accuracy or even prevent the touch screen from working.
Resistive Touch Screens
The resistive system is comprised of five components, screen base, glass panel, resistive coating, a separator dot, a conductive cover sheet and a durable top coating. When the user presses against the screen, the two layers touch, altering the electrical characteristics of the screen and allowing the system to pinpoint the spot. These screens have the advantage of not requiring skin contact, and can be used while wearing gloves or with a non-conductive stylus. The thickness of the touch screen layer, however, reduces the clarity of the display beneath.