How it works: touch screen monitor


A touch screen is a device for entering information in the form of a screen that responds to physical contact.


The touch screen was invented in the United States in the study of programming research training. The computer system PLATO IV, introduced in 1972, had a touch screen on a grid of infrared rays consisting of 16 × 16 blocks. But even such low accuracy allowed the user to select an answer by touching the desired location on a screen.

In 1971 Samuel Herst (future founder of Elographics and now Elo TouchSystems) developed the Elograph - a graphics tablet which works according to 4-wire resistive principles.

In 1974 the same Hurst managed to make the Elograph transparent; in 1977 he developed a 5-wire screen. Together with Siemens, Elographics managed to build a convex touch pad suited for screens of that time.

At the world fair in 1982 Elographics presented a TV with touch-screen.

In 1983 the HP-150 touch screen computer appeared with an IR grid. However, in those days touch screens were mostly used in industrial and medical equipment. In consumer devices (phones, PDAs etc.) touch screens came as a replacement for tiny keyboards when devices with large (the whole front panel) LCD screens began to appear.


Touch screens are used in payment terminals, information kiosks, trade automation equipment, handheld computers, and operator panels in the industry.

Advantages and disadvantages in handheld devices


Simple user interface.

Combined small size with large screen.

Quick dialing in a calm environment.

Significantly expanded multimedia capabilities.


No tactile feedback, it is difficult to work in shaking conditions. In addition you cannot dial blindly.

You must either use two hands (one with device, the second with pen) or make a large interface suitable for pressing elements with your finger, undermining the benefits of a big screen.

High power consumption.

Without special coatings, fingerprints may interfere with user interaction.

Extremely thin models of screens are at risk of breaking, even from a small impact.

Advantages and disadvantages in stationary devices


For information devices, vending machines, operator panels and other devices that do not have an active input, touch screens have proven to be a very convenient way of human interaction.

Improved reliability.

Resistance to hard external influences (including vandalism), dust and water protection


For screens that respond to touch, there is no tactile feedback.

Working with a vertical screen the user is forced to keep his hand in the air. Therefore vertical screens are only suitable for occasional use, such as in ATMs.

On a horizontal screen the hand can obscure the operator’s view.

Even with a sharp pen, parallax limits the accuracy of the operator’s actions on touch screens without a cursor. At the same time, a cursor creates additional complication for the operator reducing ergonomics.

Without special coatings, fingerprints may interfere with user interaction.

These shortcomings do not allow touch screens to be used in devices which people work on for hours.

However in competently designed devices the touch screen may not be the only input device. For example, a cashier can use the touch screen for quick selection of products and use the keyboard to enter numbers.

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