For a tablet or smartphone, the touch screen is not only a means of displaying information, but also controlling the device, which is very important. The first such display was invented back in the seventies of the last century, and actively using steel on gaming consoles and smartphones. All sensors are conventionally divided into capacitive and resistive. Resistive technology is obsolete today, but it is used quite widely, which makes it possible to significantly reduce the cost of the device. This technology implies the use of any more or less sharp object for contact with the screen, however, the list of advantages of such devices ends on the cheapness and variety of control accessories.
Capacitive touch screens are different in that gadget control can be performed only when using objects having a large capacitance that conducts a current. The screen itself is made in the form of a glass panel, covered with resistive material, which has a sufficiently high degree of transparency. When the screen is touched by fingers, or by another object that conducts current, current leakage occurs, recorded by the electrodes located at the corners of the panels. Capacitive touch screens are equipped with controllers that register the point of contact. So you get a touch to a certain point. Capacitive touch screens have a high enough reliability, allowing to carry out at least two hundred million touches.
You can consider other options of this type. The type of capacitive touchscreen became the progenitor of technology such as projection-capacitive. Here the principle of action is based on the operation of a grid of electrodes located on the inside of the screen. Together with the human body, they form a capacitor, the capacity of which changes the display controller. This technology is used in the production of the iPhone.
Capacitive touch screens have a number of advantages. They can be considered in comparison with the resistive ones, so that it becomes more obvious. Of course, in this comparison, the first win, because they have great advantages. They have a higher reliability indicator. For them there is no need for calibration. The sensitivity of such screens is much higher. Multi-touch capacitive touch screen supports multiple touch technology, which can not be said about resistive.
It is noteworthy that this way of making screens every year becomes more affordable in the end devices for buyers, today it can be increasingly seen in budget versions of tablets and touch phones. The only controversial issue is the inability to work with the stylus, but this has already been fixed. Based on the described arguments capacitive touch screens can be called at the moment the most promising in the production of tablets.