What is a touchscreen?

The sphere of mobile communication devices is developing at an unprecedented pace. Not all had time to get used to the terms "candy bar, slider and clamshell", as new ones appeared. For example, regardless of the wishes of users, manufacturers forcibly transfer everything to touch screens, refusing hardware buttons. Now the choice of push-button devices, in comparison with the sensors, is negligible. It's good or bad - time will tell, but, definitely, to know what a touchscreen is, everyone should.

This unusual term is a combination of two English words - "Touch" and "Screen", which in literal translation can be read as "touch-sensitive screen". Anyone who asks the question "touchscreen: what it is" does not always represent the field of application of this technology. Devices with touch screens residents of cities see daily several times a day: bank boxes for accepting payments, reference terminals, mobile phones, etc. When you click on certain sections of the screen, the contact is recorded and processed, according to the algorithms of the launched program. Now there is a lot of information on the Internet about what a touchscreen is. In fact, the general principle of the operation of such screens is quite simple and even a person who is far from electrical engineering will be able to understand it. However, although the term is the same, the technology used for manufacturing determines the type of touch screen.

For sure, everyone who happened to choose a modern phone, paid attention to the description of the variety of touch screen - resistive or capacitive. Anyone who understands the question "what is a touchscreen" will easily choose the best model, because he understands the difference between them.

The basis of any touchscreen is a matrix on liquid crystals (in fact, a small copy located in the monitor). On its back side are light-emitting diode lights, and on the front surface - layers that fix the pressing (resistive technology) and touch (capacitive variety).

A person who has learned what a touchscreen is, no doubt knows, that more than half of the devices use resistive touch screens. This is due to the relative simplicity of their design and cheapness. Most of the Chinese "smartphones" that flooded the market were made using resistive technology. In addition, not least, this version of the screens appeared first.

The resistive type sensor consists of two transparent plastic plates with a thin grid of conductive material located on top of the liquid crystal screen. Between them is a dielectric layer (also transparent). Since the image on the matrix is clearly visible, programs display a graphical interactive interface. The user, in response to the request of the program, clicks on a certain point of the interface (for example, the button shown). As a result, the plastic dielectric diverges, and the plastic plates touch. The current fed to the electrode of one of them falls on the grid of the other. The registering controller catches the appearance of the current and, in accordance with the grid, determines the point of depression. Its coordinates are transferred to the running program and, in accordance with the embedded algorithms, are processed.

Consequences:

• Simple touch is not enough, you just need to press;
• Because of the redistribution of the mass of the insulating layer through time, calibration of the screen is necessary;
• The number of clicks on each section of the screen is limited (from 3 to 35 million).

Capacitive screens are otherwise constructed . In them, a transparent conducting current is applied to the upper surface of the screen, with electrodes connected at the corners. When a person touches (large capacity), a leakage of current to the body occurs to such a layer. The coordinates of the touch point are calculated and processed. Touch screens, created by this technology, withstand more than 200 million touches.