To identify whether the touch screen is a resistive screen or a capacitive screen - Database & Sql Blog Articles

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AVX tantalum capacitor low resistance TPSD107K016R0100 original 2011+

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Resistive screen: The screen part of the resistive touch screen is a multi-layer composite film consisting of a layer of glass or plexiglass as the base layer, and the surface is coated with a transparent conductive layer (ITO, film), which is covered with an outer surface and hardened. Smooth, scratch-resistant plastic layer. Its inner surface is also coated with a layer of ITO, with a number of fine (less than one thousandth of an inch) transparent isolation points between the two conductive layers separating them. When the finger touches the screen, the two layers of ITO come into contact, the resistance changes, the controller calculates the coordinates of the contact point according to the detected resistance change, and then performs the corresponding operation according to the coordinate, so the technique must be applied Go to the screen to get a touch.
Capacitive screen: The capacitive touch screen works by the current sensing of the human body. The touch screen is composed of a four-layer composite glass screen. When the finger touches the touch screen, since the human body electric field, the user and the surface of the touch screen form a coupling capacitance, for the high frequency current, the capacitance is a direct conductor, so the finger sucks a small current from the contact point. This current flows out from the electrodes on the four corners of the touch screen, and the current flowing through the four electrodes is proportional to the distance from the finger to the four corners. The controller obtains the position information of the touch point by accurately calculating the ratio of the four currents. .
From the principle of the resistive screen and the capacitive screen, it can be seen that the capacitive touch screen only needs to be touched without requiring pressure to generate a signal. Capacitive touch screens require only one or no correction after production, while resistor technology requires routine correction. The life of a capacitor solution can be longer because the components in the capacitive touch screen do not require any movement. In the resistive touch screen, the upper ITO film needs to be thin enough to be elastic so as to be bent downward to contact the underlying ITO film.
To identify whether the touch screen is a resistive screen or a capacitive screen:
1. Looking inside, whether it is a resistive screen or a capacitive screen, the visual effects of both are very good. But if you put it in the sun, the effect can be quite different. The resistance screen performance will be unsatisfactory because its extra screen level reflects a lot of sunlight. Such as the Motorola "Ming" series of classic mobile phones, usually in the sun, the visibility of the naked eye is very poor.
2. Touching the resistance touch screen requires pressure to make contact with each layer of the screen. You can use your fingers, stylus, etc. to operate. The capacitive touch screen comes from the most subtle contact on the surface of the charged finger and activates the capacitive sensing system at the bottom of the screen. Non-living, nails, etc. are invalid.
3. Experiencing the fundamental characteristics of the resistive screen determines that the top of the resistive screen is soft and needs to be able to be pressed, which makes the screen very susceptible to scratches. However, since the resistive screen can be operated with a stylus or a nail, the cleanliness of the screen is still advantageous. The outer layer of the capacitive screen can be made of glass, so that although it is not indestructible, it may break under severe impact, but the glass should be easier to handle for everyday rubs and stains.
4. The cost of purchasing a resistive screen is relatively low, and the cost of a capacitive screen is relatively high. That's one of the reasons why domestic tablet prices are lower than Apple's iPad (excluding software interference).